Ten Principles of Health Cultivation — The Foundations of Wellbeing

In the history of world medicine, Chinese medicine alone possesses a longstanding and comprehensive approach to preventing illness: the art of health cultivation, or yangsheng.

Following the advanced principle set out in the Huangdi Neijing (The Yellow Emperor’s Inner Classic) — “The superior physician treats disease before it arises” — Chinese medicine has always emphasized health cultivation and regarded remaining free of disease as the best outcome.

Chinese medicine offers many methods of cultivating health. Although the ten principles introduced in this chapter represent only some of them, they embody the essence of this tradition. Their value lies in their safety and effectiveness, and in the fact that ordinary people can understand and practice them. Drawing on the experience of earlier generations, this approach advocates a modest lifestyle and a simple diet. It helps healthy people safeguard their quality of life and natural lifespan, while enabling those who have become ill through neglecting these principles to preserve both as far as possible.

This emphasis on health cultivation explains why Chinese medicine has endured, and constitutes a fundamental difference between Chinese and Western medicine.

Many illnesses are, in fact, the result of what people eat or how inactive they become. Chinese health cultivation helps people avoid precisely these problems. Simple to follow, safe, and effective, the ten principles reflect three teachings from the Huangdi Neijing:

1. The superior physician treats disease before it arises; the lesser physician treats it after it has developed.
2. The kidneys are the foundation of one’s inherited constitution; the stomach is the foundation of nourishment acquired after birth.
3. When upright qi remains within, pathogenic influences cannot invade.

Beginning with waking in the morning, this approach sets out the activities of a day in sequence. It is easy to learn and follow, and closely resembles modern medical approaches to maintaining health.

Experience has shown that people who follow these methods, even only in part, remain healthy, energetic, and physically strong, and look noticeably younger than their peers. They save on medical expenses, avoid the suffering of illness, and reduce the burden on their families. Their condition demonstrates that it is possible to avoid infectious disease; that diabetes, high blood pressure, and high blood lipids can be prevented; and that people can remain vigorous, energetic, and clear-minded well into old age.

Health cultivation is more than a means for healthy people to prevent illness and prolong life. It is also a basic form of treatment for those who have become ill without practicing it. My point is this: seeking treatment when ill may sound right, but the approach is incomplete if it stops there. A patient should first examine whether their lifestyle is healthy. Every aspect of how we live has pharmacological effects; these effects are not confined to medicines. People who continue to seriously violate the principles of healthy living are creating illness while receiving treatment, making recovery extremely difficult.

Everyone should therefore correct unhealthy ways of living. We must gradually learn to seek health through a lifestyle consistent with the principles of health cultivation. In this way, illness can resolve more quickly, and a long, healthy life becomes more attainable.

The Appended Statements in the Commentaries on the Book of Changes says: “What is easy is easy to understand; what is simple is easy to follow.” Health cultivation must be understandable to be mastered, and simple to be followed. The ten principles in this book are so straightforward that their simplicity may invite doubt. Yet that very simplicity makes them worth sharing widely. Their ease of practice is one reason Bencao Yangzheng Tang is committed to promoting them.

Of course, everyone has the right to choose how to prevent and treat illness. The natural human lifespan is approximately 120 years, yet most people die prematurely from disease — and it is often we ourselves who wear our lives away. Life deserves to be cherished. I hope everyone will treat their own life with care.

1. Drink Water on Rising: The First Principle of Health Cultivation

The first thing to do on getting up is drink boiled water that has been allowed to cool. Then urinate, wash your face, exercise, and eat breakfast. As the ancients said, “Stomach qi is weakest on rising; drink water to stimulate it.”

Drinking cooled boiled water in the morning has six benefits:

First, when a person has just awakened, stomach qi is at its weakest. It is not yet time to eat; cooled boiled water should be used to stimulate the gastrointestinal tract and prompt the hypothalamus to produce hunger — what is commonly called “waking the stomach.” Morning water also washes the digestive tract, dilutes stomach acid, reduces irritation, and helps keep the stomach and intestines in optimal condition. People with small appetites who feel uncomfortable after eating a little more can greatly increase their appetite by making a large glass of cooled boiled water on an empty stomach a daily habit.

Second, waking is a crucial time to replenish the body’s water for the new day. During sleep, substantial water is lost through urine, skin, and breathing, leaving the body physiologically short of water by morning. Approximately 400 milliliters are lost overnight. Drinking cooled boiled water on rising replaces water lost through metabolism.

Third, it stimulates gastrointestinal movement, moistens the intestines, softens stools, encourages bowel movements, and prevents or relieves constipation. People who develop this habit often find that a large glass of water soon creates an urgent need to move their bowels. This is why.

Fourth, the intestinal lining rapidly absorbs the water into the bloodstream, effectively increasing blood volume, diluting the blood, reducing its viscosity, improving circulation, and preventing cardiovascular and cerebrovascular disease. The first two or three hours after rising are a peak period for these events. Some older people who die of a heart attack in the morning were, in fact, missing only a large glass of boiled water.

Fifth, it helps the body eliminate toxins and moisturizes the skin. Besides encouraging bowel movements, morning water helps metabolic toxins accumulated overnight leave promptly through the urine. Mild suboptimal-health symptoms, such as poor sleep or a dull complexion, are actually mild autointoxication and can therefore be corrected with a large glass of cooled boiled water each morning.

Sixth, drinking water on rising quickly restores mental alertness, preparing a person for the day’s study, work, and everyday activities.

Eat breakfast half an hour after drinking your morning water. Fresh gastric juices will have been secreted by then, allowing nutrients to be absorbed well. Avoid drinking water as far as possible for half an hour after meals — generally, wait two hours before drinking large amounts — to maintain a sufficient concentration of digestive juices. Drinking water half an hour before a meal, however, is beneficial because it ensures adequate digestive secretions. Leaving roughly half an hour between substantial drinking and eating is basic knowledge in health cultivation. In particular, do not drink large amounts immediately after a meal: this dilutes the digestive juices and causes the diluted food to leave the stomach quickly, impairing digestion and absorption.

Drinking cup after cup of tea immediately after a large meal reveals a lack of understanding of health cultivation.

Breakfast must be eaten, and eaten well. The stomach meridian is most active from 7–9 a.m., and the spleen meridian from 9–11 a.m. Eating between 7 and 9 therefore favors digestion and absorption. Otherwise, the stomach works without food during its peak period, causing dizziness and, over time, considerable harm. This is also when yang qi in nature and the body is becoming increasingly vigorous. Strong yang qi favors the transformation of food, so a substantial breakfast will not make a person fat.

During the morning, bodily yang qi is increasing while both the stomach and spleen meridians are at their most active.

Many people make dinner their main meal, neglecting breakfast and lunch and eating very little at either. They end up with both a weak constitution and excess weight. Eat little or nothing at dinner, and always eat a good breakfast. Eating and sleeping in accordance with the natural rhythms of heaven and earth makes illness less likely.

Skipping breakfast not only fails to supply the energy needed for the morning; it also affects bile secretion. Poor bile secretion encourages gallstones and affects gastric digestive secretions, impairing the digestion and absorption of lunch. Those who skip breakfast therefore absorb lunch poorly as well. Suppose someone would normally absorb 30% of their lunch: after skipping breakfast, that figure might fall below 25%. Continued over time, this readily leads to health problems.

Observing the people around you will make this clear. Be sure, therefore, to eat a good breakfast.

Breakfast should be nutritious and easy to digest. Avoid foods such as sticky-rice dumplings that are difficult to digest. Modern medicine has found that human metabolic rate is lowest at around 4 a.m.; heart rate, breathing rate, and digestive secretions are also at their lowest. Difficult-to-digest foods are therefore unsuitable immediately after rising. How can the digestive tract be brought into action more quickly? By drinking water. Clinical experience shows that many stomach problems result from hurriedly eating immediately on waking before rushing to work. Many others arise from skipping breakfast or eating foods that are hard to digest.

Many people eat as soon as they open their eyes, sometimes even in bed. Is that a blessing? No. Others immediately drink beverages, or even alcohol. Is that a blessing? No. These habits violate the laws of life and diminish both wellbeing and longevity. It would be surprising if they did not cause illness and shorten life.

The following points also deserve attention:

1. For healthy people, boiled water cooled to 22–25°C is generally best; water freshly boiled and then cooled offers the greatest health benefit. In spring and summer, a convenient practice is to boil it in the evening and place it in a sealed cup that allows heat to escape, ready for the morning. Remember that “cool” means room temperature, generally no lower than 18°C. In cold autumn and winter weather, freshly boiled water cooled to near body temperature is preferable. Begin with half a jin of water in the morning, gradually increasing to around 1 jin.

During the rest of the day, drink before thirst becomes pronounced, but not excessively. Drink enough to relieve thirst; as with eating, stopping halfway to fullness is sufficient. Also avoid drinking too much before bed.

2. Never refrigerate the water. Its cold qi is harmful and injures the spleen. As bodily yang qi begins to rise in the morning, refrigerated water obstructs this natural process and is extremely detrimental to health.
3. Menstruating women and people with stomach disorders should drink warm boiled water, particularly in winter for those menstruating or suffering from stomach cold. Women recovering from childbirth, people weakened by serious illness, and those with spleen or qi deficiency should favor warm-to-hot boiled water on rising. Middle-aged and older people over 45 whose spleen and stomach function has noticeably declined should also drink water near body temperature when the weather is cool. People with sensitive stomachs, rheumatism, gout, or bladder disease should likewise avoid cooled water, as a sudden temperature drop can worsen their condition. Water close to body temperature, preferably no hotter than 45°C, is suitable for them.
4. Unboiled mineral or purified water cannot replace cooled boiled water. Remember the ancient maxim: boil water before drinking it. Beyond hygiene, boiling makes water neutral and slightly warming in nature, which benefits the body. Unboiled water is somewhat cold in nature, and prolonged consumption damages spleen and stomach yang qi.
5. Morning exercise helps yang qi rise, so move your body in the morning. Walking, jogging, tai chi, hill walking, dancing, and fitness exercises are all options. Generally, loosening up the body until it feels warm or lightly perspiring is enough. This encourages yang qi to rise without rising too quickly and dispersing. Avoid excessive exercise that depletes it. Everyone’s condition differs, so choose an intensity that feels appropriate. Reduce the amount if you feel physically exhausted afterward.

Those interested may investigate this: people who work up a heavy sweat in the morning may be physically fit, yet most do not live especially long. Younger people, of course, have abundant original qi and may increase morning exercise intensity to improve sporting performance and fitness.

6. During the mao period, 5–7 a.m., the large-intestine meridian is most active. “The lungs and large intestine form an interior–exterior pair.” During the preceding yin period, 3–5 a.m., the lungs distribute abundant fresh blood throughout the body, subsequently stimulating the large intestine to absorb water and nutrients and eliminate waste. Rising, drinking water, urinating, moving the bowels, and exercising should therefore take place during mao, 5–7 a.m., although outdoor exercise should not begin too early during the three winter months. Since the large-intestine meridian is strongest then, morning water provides further stimulation and makes bowel movements smooth and easy. This is another small secret of health cultivation.

Following the above instructions will establish a daily morning bowel habit. Remember: 5–7 a.m. is an important period for eliminating the day’s waste. Drink water before urinating or moving your bowels.

7. During the chen period, 7–9 a.m., the stomach meridian is most active and digestion and absorption are most efficient. Breakfast should therefore be eaten before or around 7 a.m. This gives the stomach food to process throughout the full two-hour chen period, generally completing digestion by about 10:30 a.m., as mentioned earlier. Although 7–9 a.m. is the first eating period of the day, arrange breakfast toward its beginning. Only by eating before or around 7 can the stomach finish digesting at about 10:30, allowing you to “eat when the intestines rumble” at noon.

You will then approach lunch with a strong appetite and digest and absorb it well.

Intestinal rumbling marks the digestive tract’s entry into its optimal state of qi transformation, when eating produces the best nutrient absorption. Those who delay breakfast until around 9 or 10 miss the morning’s best digestive period. By noon they feel no hunger, eat little, and digest even that poorly, creating a vicious circle. Over time, this can damage health and weaken the constitution.

Some now suggest eating only twice daily, with the first meal between a little after 8 and around 9 a.m., and the second between a little after 2 and around 3 p.m. Leaving aside whether this is scientific, it is difficult to implement within current social eating and working habits. I therefore regard breakfast at around 7 a.m. as the scientifically sound arrangement.

8. Drink in moderation. Some mistakenly believe that more water is always better because it removes more harmful substances, and consequently drink seven or eight jin a day. Both the belief and the practice are wrong. Excess water not only disturbs cellular fluid balance, causing a dull complexion, enlarged pores, or swelling of the limbs; it also carries substantial nutrients and trace elements out of the body. Apart from morning drinking, take water when thirst is beginning but is not yet pronounced, and stop when it is relieved.

Excessive drinking does not detoxify the body; instead, it increases the kidneys’ burden and causes kidney deficiency. Naturally, more fluid is needed with heavy perspiration or exercise. Overall, however, most people currently drink too little.

9. Drink good-quality water, preferably uncontaminated natural water such as mountain spring water. Long-term consumption of purified water is not recommended. Because tap water in some cities does not meet drinking-water standards, be willing to spend money on bottled drinking water to boil, or on a purifier that brings tap water up to drinking-water standards before boiling it.

2. Drink Meat Broth and Eat Coarse Grains and Vegetables at Midday: The Second Principle

At lunch, drink meat broth first, followed by coarse grains and vegetable dishes. As the ancients said, “At midday, drink meat broth rather than eat pieces of meat, gaining nourishment while avoiding meat toxins; then eat coarse grains and vegetables to bind intestinal toxins. This is eating to seventy percent full.” Do not eat lunch too late; around 11 a.m. is best.

Broth may be made from beef, pork, lamb, scaled fish, chicken, or duck. Wash the meat, soak it in clean water for an hour, then place it in a pot and simmer over low heat for 12 hours, until it falls apart. Low heat must be used from the beginning. Once cooked, remove the fat and meat residue before serving. Only broth prepared this way is a highly nourishing concentrated broth. Thick and quite different from water or ordinary vegetable soup, it is an excellent health-cultivating food to take on an empty stomach.

There are two ways to consume it. One is to drink one or two small bowls before eating the other foods at a meal. The other is to add vegetables and make soups of different flavors, again drinking the soup first. The broth can also be used to stir-fry vegetables, giving them a delicious flavor. Remove the floating fat: after straining out the meat residue, refrigerate the broth briefly, scrape off the surface fat, and reheat before serving.

A basic dietary principle is to make coarse grains the main staple, with refined grains playing a supporting role. Choices include corn, millet, buckwheat, barley, beans, sweet potatoes, and taro. Eat plenty of beans. Chinese diets commonly provide insufficient high-quality protein, leaving the body less robust. Among coarse staples, beans deserve particular emphasis: they supply high-quality plant protein and, from the perspective of Chinese medicine, nourish the kidneys. Alongside more coarse grains and beans at lunch, preferably make your own soy milk in the morning.

My habit is to make morning soy milk from soybeans and white sesame seeds, or to have a bowl of nourishing congee or some meat broth, accompanied by a coarse-grain staple. Corn was once called “imperial grain”; even emperors recognized its value. Eating more corn can help reduce weight. Steamed corn-and-soybean buns, or wotou, make a good staple, although they are not appetizing when poorly prepared.

Vegetable dishes may include carrots, pumpkin, tomatoes, potatoes, radishes, eggplant, winter melon, Chinese yam, and Chinese cabbage. Eat these generously. Use water or meat broth instead of cooking oil whenever possible: high heat alters vegetable oil, making it extremely harmful. Flavor enhancers are also harmful and best avoided; even salt should be used sparingly. Once accustomed to this diet, you will find food’s natural flavor the most delicious.

Here the ancients introduce two concepts: avoiding meat toxins and binding intestinal toxins.

What Does “Avoiding Meat Toxins” Mean?

The ancients said, “Meat broth does no harm, but pieces of meat entering the belly generate meat toxins and cause great harm.” In other words, broth is absorbed directly and produces almost no stool, so it does not injure the body. Pieces of meat, however, form stool in the colon and do cause harm. Is this true?

Modern medicine has found that the body absorbs, at most, about 30% of meat eaten in pieces; thorough cooking until soft can improve this rate. The remaining 70% forms stool in the colon. Fermentation of this meat-derived stool produces many harmful chemicals — carbon dioxide, methane, histamine, tryptamine, ammonia, indole, phenols, skatole, sulfate esters, hydrogen sulfide, and others — causing what is called autointoxication. Its immediate signs include fatigue, irritability, loss of appetite, constipation, internal heat, repeated minor illnesses, and even bone pain throughout the body. Longer-term effects include premature aging and a shortened life.

Observe people particularly fond of making meat their main food: compared with their peers, they often have poorer physical stamina, especially endurance, and rougher skin.

Meat left outdoors at 37°C soon rots and smells. What happens when it is placed inside the belly? Fortunately, the body can detoxify itself; otherwise, the consequences would be difficult to imagine. Most people absorb meat’s nutrients while simultaneously being poisoned by its toxins. If we could obtain its nourishment without those toxins, our health would improve greatly.

Steak, pork chops, stewed chicken, stir-fried sliced meat, and roast duck therefore bring both benefits and harm. After the enjoyment of eating, only some nutrients are absorbed; the rest becomes a bellyful of foul-smelling stool. Meat-derived stool is particularly offensive. Once its toxins are absorbed, the harm is incalculable, providing an unrecognized cause of many otherwise mysterious illnesses. Avoiding pieces of meat, and thus avoiding the production of this stool, can prevent many diseases.

Some say that broth, like meat, raises cholesterol. This is incorrect. The floating fat has already been removed from broth, so it contains no cholesterol. Fat is difficult to remove completely from pieces of meat, making cholesterol intake much more likely.

Humans must replenish animal protein: children need it to grow, and adults need it too. Daily cellular metabolism loses substantial animal protein that must be replaced through food, so plant protein alone is insufficient. Broth is readily absorbed directly without forming stool or causing autointoxication. This is why Chinese medicine advocates it. Drinking broth before each meal naturally prevents overeating — this is what it means to eat to seventy percent full.

People must eat to survive, so stool is inevitable. What kind is less harmful? That produced by a vegetarian diet. Vegetarian food does not produce foul-smelling stool and also has a therapeutic effect: it binds intestinal toxins. Because their cell walls differ, coarse grains produce more stool than refined grains.

On reflection, the body resembles a length of bamboo: empty inside and surrounded by space outside, with only the intervening layer constituting the body itself. Why? Think of the hollow passage from mouth to anus. Unlike bamboo’s straight channel, ours winds and curves. This inner space is the internal environment, while the space we see outside is the external environment. Only when both are good and clean can we remain healthy and free of disease. My opposition to eating pieces of meat is intended to keep our internal environment as clean and sound as possible.

Although people now acknowledge that fat is harmful, most still believe refined grains should be the human staple.

Refined grains and fats provide abundant calories. Most of us grew up eating refined grains, yet humans do not need a high-calorie diet. Such diets readily cause many diseases and make many illnesses difficult to treat. A staple diet based on coarse grains is more beneficial to health.

Why? Coarse and refined grains differ in their calorie content: coarse grains are low in calories, refined grains high. As warm-blooded animals, humans should favor lower-calorie foods. May refined grains be eaten? Yes, but not excessively; roughly twenty to thirty percent of staple foods is preferable, with coarse grains forming the majority. Rice, the staple most widely eaten in southern China, is only one of the five grains. Eating rice while excluding the other four is already an imbalance.

For thousands of years, residents of many regions of China have indeed relied on rice. This has given rice a strong affinity with our bodies, making its nutrients easy to absorb — an indisputable fact. However, rice’s nutrients are concentrated mainly in the germ. The rice we eat today has lost its germ, is nutritionally poor, and can lead to malnutrition. This is another major problem with rice today.

People with heat-type illnesses, high blood lipids, high blood pressure, or diabetes should eat more coarse grains. Those with heat-type conditions such as cancer, hepatitis, or mental illness should preferably replace refined-grain staples altogether. Refined grains — rice, sticky rice, and white flour, for example — contain substantial starch and supply many calories. Excess calories in these patients cause symptoms such as fever, pain, and irritability. Naturally, people with heat-type illnesses should be especially careful to avoid sugars.

In particular, avoid garlic, scallions, onions, and Chinese chives as far as possible; even healthy people should not eat them. Some believe they kill germs and reduce inflammation, but must we rely on them for those purposes? Why advise against them? These are foods that provoke illness and readily direct qi upward. For people with high blood pressure, glaucoma, diabetes, high blood lipids, or cerebral vascular blockage, they rapidly draw qi upward and must not be eaten. Cancer patients should pay still greater attention.

These provocative foods are also generally warming, readily causing heat in the blood and its reckless movement, which harms health. Historically, in Buddhism, the term hun referred first to garlic, scallions, onions, chives, and similar foods that cause turbid qi to rise, rather than to meat. By making the mind dull, they obstruct spiritual practice and health. Thus hun, “pungent foods,” is associated with hun, “mental dullness.” Avoiding them makes the mind much clearer and the eyes brighter. Once this is understood, garlic, scallions, onions, and other heating, provocative ingredients should no longer be used in cooking.

Yet how many people will listen? People always trust what newspapers, television, experts, and professors say. Naturally, readers should examine my words critically as well, preferably testing them personally before accepting them. People tend to depend on established habits and resist changing familiar ideas. They prefer arranging life around subjective sensory desires instead of adapting to physiological needs. Changing our habits is truly difficult.

Many vegetarians oppose animal protein because it contains bacteria, viruses, parasites, antibiotics, animal growth hormones, and other harmful substances that can cause illness when consumed in quantity. There is some reason to this. However, prolonged high-temperature cooking into broth avoids these problems, because sustained heat can neutralize all manner of toxins. The real issue with animal protein is not whether it is eaten, but the stool produced afterward. Preventing it from forming toxic stool prevents the harm.

Conversely, vegetarians who consume large quantities of starch, vegetable oil, scallions, ginger, garlic, chili, and other heating foods also harm their bodies. Chinese people consume more of these heating foods than any other population and are consequently among those with relatively high rates of disease. Although vegetarians advocate a light diet, without understanding health cultivation they may actually eat high-calorie foods, leaving disease rates high.

Even vegetarians who avoid high-calorie foods will naturally experience a decline in vitality and health over time without replenishing animal protein. Many become very weak after several months or half a year of vegetarian eating. People can be vegetarian, but a prerequisite applies. What is it? I will discuss it in detail in a future book. In certain circumstances, vegetarianism is necessary; for ordinary people like us, eating only vegetarian food is not scientifically sound.

Many parents are distressed by children who stay awake at night, cry during the day, and frequently run fevers. Why does this happen? They have given the children too many refined grains and other high-calorie foods. With excessive calories, children naturally need an outlet. On whom do they vent? Their parents, of course — keeping them awake at night, anxious by day, and rushing to emergency departments. These seemingly inexplicable problems arise from inappropriate dietary arrangements.

As children grow, they may be unable to sit and read, restless, preoccupied with play, and disruptive, prompting repeated calls from teachers. The cause may be too many refined grains, fats, sweets, chocolate, and similar foods. Excess calories are behind it all.

You may have a minor illness that never improves despite treatment, leaving you distressed. Is there no miraculous remedy? If you eat harmful things all day, nobody can save you. What are these harmful things? High-calorie foods such as fats, sweets, chocolate, and potato chips.

Perhaps you care for both parents and children: the older people are riddled with illness, the children constantly misbehave, and you feel unwell too. Why is the whole household unsettled? You have allowed everyone to eat and drink indiscriminately. After satisfying their appetites, the entire family suffers the consequences.

Would you like peace and health for the whole family? Here is the secret: more coarse grains and fewer refined grains, more meat broth and vegetables, and little or no animal fat, sweets, chocolate, potato chips, or other miscellaneous high-calorie foods.

Many people struggle to follow all ten principles. Some cannot immediately change their habits; others lack their family’s understanding or face constraints at work and home. Diet is often the most difficult area, yet it is crucial. Humans are born with two great appetites: sexual desire and the desire for food. Mismanaged sexual desire injures one’s roots; mismanaged appetite damages one’s foundation. Folk sayings such as “Illness enters through the mouth” and “Age begins in the legs; death comes through the mouth” explain that food sustains life but can also damage it when consumed improperly.

If you cannot yet arrange your diet as described, observing the following points can still count as practicing health cultivation well.

Specifically:

1. Keep the diet light, balance food proportions sensibly, and eat according to need. Favor plant foods over meat, cook meat thoroughly until tender, and prefer mild flavors to strong ones.

Modern people’s long reliance on refined grains has left their digestive systems insufficiently exercised and their absorptive function diminished. They have also moved away from nature: from single-story homes to high-rises, and from walking to riding in vehicles. The earth governs yin; static electricity generated by bodily friction must be discharged through contact with the ground. Separation from the earth produces deficient yin and excessive yang, naturally weakening internal-organ function and immunity. Whenever possible, walk barefoot on grass or soil, especially children. Together, these changes have reduced modern people’s ability to digest, absorb, and eliminate animal proteins and fats compared with the ancients.

Eating too much meat without corresponding expenditure inevitably leaves surplus material to putrefy within the body, causing autointoxication — what the folk saying describes as “Meat produces phlegm; fish produces fire.”

Remember that saying: “Meat produces phlegm; fish produces fire.” Meat readily produces phlegm and fish internal heat. If phlegm and fire are present, eat less meat. Too many pieces of meat also cause mental dullness. The qi of animal flesh is coarser than that of plants; making broth refines it considerably, which is why broth is advocated. Processing meat is more demanding for the spleen and stomach, while the brain needs very refined qi for nourishment. Excess meat impairs transformation and circulation, clouding the mind.

This is one important underlying reason that monastic practitioners avoid animal flesh. Sensitive people may feel mentally dull immediately after eating large amounts of rich, greasy dog meat, lamb, or beef for precisely this reason. Habitual meat eaters who adopt a vegetarian diet for a time may lose some strength but become much clearer mentally. This recalls a line I learned as a child in Cao Gui’s Discussion of Warfare: “The meat eaters are narrow-minded and incapable of far-reaching plans.” Looking back, Cao Gui was quite right; his observation has a scientific basis.

An ancient commentator explained: “To call meat eaters narrow-minded is not to despise their eating of meat, but their inability to plan well. Their poor judgment arises because rich, greasy essences congeal into fat, obstructing the chest and heart, as though thatching over the mind until none of its openings remain. This is not my conjecture; it has been verified.” How can turbid qi from excess meat be prevented from rising to the brain? Eat more plant food and less meat, and prepare meat as broth. Parents who want children to do well at school should give them more coarse grains, vegetable dishes, and meat broth.

If you continue eating pieces of meat, stronger digestion permits more, while weaker digestion calls for less. Younger people may eat somewhat more; older people with weak stomach qi should eat less, though they should still drink plenty of broth. There is no fixed proportion: the amount should depend on individual digestive strength. No abdominal bloating or unpleasant mouth odor after meat indicates a normal response; otherwise, reduce the quantity. This applies to young and old alike.

If meat is not made into broth, cook it thoroughly until very soft. Humans originally ate meat raw; learning to cook it over fire improved the human constitution. Stewing meat until very tender and consuming both meat and broth improves absorption, reduces meat-derived stool, and noticeably improves physical condition, most obviously through increased strength. Drinking only broth, thus taking in only hydrolyzed animal protein, raises physical condition to another level.

If you cannot forgo the pleasure of meat, cook it as thoroughly and tenderly as possible to improve absorption and utilization. This allows enjoyment and nourishment while minimizing meat-derived stool and exposure to meat toxins. It is a simple principle of health cultivation and a moderate compromise.

Thoroughly stewing meat and consuming both meat and broth has long been advocated. Ancient Chinese sages emphasized that “Thin congee and tender meat do not injure the spleen and stomach.” Fish and meat should be stewed until tender for easy digestion and absorption, hence another saying: “Boil tofu a thousand times; stew fish ten thousand times.” This particularly matters for older people and children with weak spleen and stomach function. The late-Qing statesman Zeng Guofan paid close attention to it. In a letter to his younger brother, he wrote: “My present regimen requires food to be carefully prepared. Vegetables are cooked in meat broth, and chicken, duck, fish, lamb, and pork are all stewed until very tender. To my mind, this is the most delicious and nourishing food under heaven.”

I knew a man who remained healthy and lived to 92. He especially liked pig’s trotters and ate them weekly in later life — twice a week once he could afford it. They were simmered for three or four hours until completely soft. He removed the bones and surface fat and mixed the meat with rice, obtaining both good nourishment and high absorption. Had he known the ten principles, however, he would have simmered the trotters in water for 12 hours, removed the floating fat and meat residue, and drunk the broth or mixed it with rice. The health benefits would have been greater, and his life should have been longer still.

Soybeans stewed with beef or pig’s trotters provide good nutrition once the floating fat is removed. In my view, before middle age, when spleen and stomach function is strong, some thoroughly stewed meat and broth are acceptable. After middle age, gradually emphasize broth; older people over 70 should switch entirely to broth. This too broadly counts as sound health cultivation. Better still, develop from childhood the habit of drinking meat broth or using it to cook vegetables and soups. This is simply a dietary habit; the principal change is in cooking methods.

A good dietary habit will benefit you throughout life.

Many people nevertheless prefer culinary pleasure to health and longevity. Living in southern China, I often see people enjoying partly raw fish and meat, which is detrimental to health. Some southern regions spend heavily per person on food, yet rank poorly nationally in physical health. This deserves thought and attention.

There are additional reasons to cook meat thoroughly. Like humans, pigs, cattle, and sheep are mammals and may suffer many of the same diseases, including hepatitis. Some people like stir-fried liver particularly tender, sometimes with traces of blood still visible. If it contains hepatitis pathogens, these may infect people with weak immunity.

Chinese people should eat less meat and more plant seeds, making seeds the dietary staple — predominantly coarse grains, with particular emphasis on beans. Seeds possess the greatest vitality: to reproduce, every species provides its seeds with the richest nutrients and immune substances. Seeds should therefore be our principal food; birds’ eggs also belong in this category. Egg yolks are high in cholesterol and should be limited; one yolk daily is appropriate for a healthy person. More egg white may be eaten. Many athletes in China and abroad eat only the whites, discarding the yolks.

Seeds and vegetables are light and pure foods. Eaten correctly, they return that lightness and purity at a higher level. Among seeds, coarse grains should again predominate.

Most ethnic groups in China have historically relied on farming, obtaining their food principally from the land. The Huangdi Neijing says, “The five grains nourish, the five fruits assist, and the five domestic animals supplement.” This shows that our ancestors ate plant seeds as their staple and that we, too, can only do the same. It is the result of thousands of years of inherited genes and cannot be changed. Because our staple foods are fibrous plant seeds, Chinese people use chopsticks: one cannot realistically eat millet with a knife in one hand and a fork in the other.

Westerners are different. They use knives and forks because their ancestors ate meat; most were nomadic peoples whose staple was meat. Continual meat eating intensifies internal fire, creating excessive heat that must be balanced with iced water, raw vegetables, and fruit. Their dietary and lifestyle habits therefore do need to differ from those of Chinese people. This is a simple principle, yet many fail to understand it and mistake suffering for enjoyment.

Look around: many Chinese people have become enthusiastic meat eaters, making pieces of meat their staple and reversing the proper order. Older people are somewhat better because weakened stomach qi prevents them from eating too much. Many in their forties and fifties went hungry as children; now that they can afford it, they indulge daily in meat and alcohol. The result is a headlong rise in high blood pressure and high blood lipids. If you use a digestive system inherited for processing fibrous foods to tackle steaks and chicken legs, it is hardly surprising that metabolic disease follows.

The Huangdi Neijing says, “The changes brought by rich food can give rise to great sores.” Large quantities of meat and high-calorie foods, together with abrupt dietary change, have produced today’s high incidence in China of metabolic diseases such as elevated blood lipids, high blood pressure, and diabetes. Once chiefly diseases of wealthy households, they now readily affect ordinary people too. As the poem says, “The swallows once beneath the eaves of Wang and Xie now fly into the homes of common people.”

2. Keep food fresh.

Freshness means eating fresh food. Vegetables, fish, and meat remain fresh only for a limited time; as they approach deterioration, they do harm rather than good. Southern Chinese people do well in this regard, valuing newly picked vegetables and fresh meat, fish, and shrimp, whereas some northerners pay less attention. One point deserves emphasis: soy milk may be consumed generously, but tofu damages stomach qi and should be limited or avoided. Why, when both are made from soybeans? Whenever I advise against frequent or excessive tofu consumption, people usually assume I am uneducated and talking nonsense.

To explain, let me begin with a story about tofu’s origins.

In 164 BCE, Emperor Wen of Han appointed his younger brother Liu An Prince of Huainan. Liu An admired Daoist adepts and regularly gathered thousands at his residence to practice alchemy. They often used highly toxic bittern. Once, an adept accidentally dropped some into soy milk, which coagulated. He thought the milk had spoiled, but others tasted it and found it edible. Thus a new food appeared: tofu, or doufu, whose name, taken literally, means spoiled soy milk.

This is why it is called doufu rather than “bean treasure,” “precious bean,” or “bean essence.” Yet the Daoists praised it as “condensing the essence of heaven and earth and augmenting the vital endowment of creation,” widely promoting its consumption. First the adepts ate it, then ordinary people gradually adopted it, and it remains a daily Daoist food. Liu An failed to produce an elixir but accidentally obtained tofu. Eating it did not prolong his life. Indeed, perhaps too much tofu muddled his mind: he overestimated himself and plotted to usurp Emperor Wu’s throne.

In 122 BCE, Emperor Wu discovered the plot. Knowing the seriousness of his crime, Liu An killed himself in fear of punishment. Later, some considered highly toxic bittern too alarming an ingredient and discovered that adding gypsum to soy milk also produced tofu. Two types thus emerged: northern tofu made with bittern, and southern tofu made with calcined gypsum. Both, however, are harmful to the body.

Bittern is a water-soluble mineral whose chemical constituent is magnesium chloride. Acute magnesium chloride poisoning can cause hypermagnesemia and cardiac arrest; chronic poisoning can damage both kidneys and cause uremia. People formerly often killed themselves by drinking bittern. In the Chinese film The White-Haired Girl, Xi’er’s father, Yang Bailao, dies this way. Bittern is still classified as highly toxic, and even tofu factories strictly control its issue through their security departments. Why would you eat northern tofu?

Is southern tofu safe, then? No, because it uses calcined gypsum, chemically dehydrated calcium sulfate. This material is used to make statues; it hardens on contact with water and is not absorbed by the body. People have accidentally swallowed it and obstructed their digestive tracts. The only treatment in such cases is to cut the gastrointestinal tract open surgically and remove the gypsum that has formed a cast of it. Japan reportedly now has new tofu-making methods. I do not know whether that tofu is edible, but imagine the underlying principle remains the same.

In Chinese medicine, tofu’s harm can be expressed in one sentence: it injures spleen and stomach yang qi. Why does it injure stomach qi? Yin–yang theory holds that yin condenses things into form while yang transforms them into formlessness. Water vapor meets cold, or yin, and condenses into droplets; water exposed to subzero cold becomes ice. Conversely, heat, or yang, melts ice into water and evaporates water into the air. Turning liquid soy milk into solid tofu requires a yin-cold substance. Are bittern and gypsum such substances?

Yes. Bittern is bitter and cold; gypsum is pungent, sweet, and extremely cold, while calcined gypsum is slightly cold. Excessive yin-cold substances inevitably damage spleen and stomach yang qi and the foundation of postnatal nourishment. Chinese medicine holds that “Whatever damages stomach qi is called a toxin.” Can you live long while consuming toxins every day?

An astute person can understand this from the old health maxim “Boil tofu a thousand times; stew fish ten thousand times.” If ancient tofu contained no toxins, why boil it for so long at high temperature to neutralize them? Does the saying mean fish is toxic too? Fish does not require prolonged cooking because it is inherently toxic, but because eating it directly readily creates phlegm and fire and produces foul-smelling stool. Besides, farmed fish today is contaminated and toxic as well.

Today’s tofu differs from ancient tofu, however. Continuous improvements in production have indeed greatly reduced its toxicity. It is simply somewhat cold in nature, so people with stomach heat may eat more to restore balance. For people with stomach cold, however, it is unsuitable and noticeably harms the spleen and stomach.

Nobody would knowingly eat completely rotten fruit. But when only part is rotten, some people economize by cutting it away and eating the rest, believing this hygienic. It is not. A fruit is a whole, its internal circulatory network interconnected like human blood vessels. When one part rots, the contamination has already circulated throughout. An off-flavor in the apparently sound part proves this. The same applies to vegetables. Scientific experiments have shown that when one area of a fruit or vegetable rots, harmful substances already exist in the apparently intact portions.

Fish and meat are, in fact, animal carcasses; once spoiled, they are decomposing carcasses whose toxicity harms people. Common cases of food poisoning demonstrate this.

Most people will not eat thoroughly foul-smelling fish or meat. Yet some mask the odor of less-than-fresh products with chili, Sichuan pepper, yellow rice wine, ginger, and other seasonings. This is self-deception. Seasonings conceal smells but cannot readily eliminate toxicity. Toxic food damages the body instead of nourishing it; better not to eat it.

Cured meat, cured fish, salted meat, and similar foods are animal mummies — preservation methods invented when refrigeration was unavailable. Modern people can eat fresh food and should not become overly attached to cured products. A little for the flavor is acceptable; prolonged consumption is inevitably harmful. Modern science has established that these products contain many substances unfavorable to health.

3. Keep food clean. Washing the surfaces of vegetables and fruit is something everyone can do, but ensuring relative cleanliness inside them is often overlooked.

Modern pollution affects fruit and vegetables in many ways, including pesticide residues and the penetration of chemical fertilizers. After washing vegetables, preferably soak them in clean water for a time so that water-soluble harmful substances dissolve into it.

Farmed fish, shrimp, chickens, and ducks may receive feed containing growth promoters, urea, and other additives that accelerate fattening. Cut meat should preferably be soaked so that soluble substances can leach out. This is only a temporary expedient, however. The best and most thorough method is making broth. After a night of low-heat simmering, the proteins are hydrolyzed into readily absorbed amino acids and all toxins are neutralized.

Older people in particular, whose liver detoxification function is weaker, should make broth from farmed chicken, duck, fish, and meat. Their other bodily functions also decline. Without attention to what and how they eat, what else accumulates in the body? Harmful hormonal substances. Once substantial quantities build up, they are difficult to break down and can lead to diabetes, high blood pressure, glaucoma, coronary heart disease, various cancers, and other diseases of modern civilization.

Do not overindulge in seafood, especially if you come from inland. Coastal populations are physiologically somewhat more accustomed to it; excessive consumption harms inland people’s health. Shrimp and crab are high in protein, but much of it is foreign protein that the body cannot absorb. It can temporarily supply needed protein, yet two or three days later it passes out in the stool. Seafood such as shrimp and crab is generally best dipped in vinegar, which helps break down and absorb these foreign proteins.

Eating shrimp and crab thus amounts largely to satisfying the palate.

Seafood is delicious, but too much burdens the liver. Many people in China’s coastal regions have liver disease; the five types of hepatitis, including A, B, C, and D, are more common there, with proportions far higher than inland. One reason is excessive consumption of shrimp, crab, and other seafood. Anyone claiming that sea produce is fresh and uncontaminated likely lacks common sense. Water ultimately flows into the sea, taking pollution from the land with it.

The sea is, in effect, a vast dye vat. How could it remain unpolluted?

Scaled marine fish such as yellow croaker may still be eaten, preferably as broth. Squid, shrimp, and crab should be limited to a little for the taste; excess burdens the liver. Remember especially that eating shrimp and crab can readily trigger rapid tumor growth and the rapid spread and metastasis of cancer cells in people with tumors.

Truly clean eating is difficult in modern society. Environmental contamination is everywhere, reaching every aspect of life. To respond properly to these conditions, we must adjust and control what enters through the mouth.

In sum, food entering the digestive tract must be light, fresh, and clean to maintain health. According to the principle of yin and yang embracing one another, the pure and the turbid attract. Fresh, pure food binds with impure substances, and they leave the body together.

Four Further Points on Diet

1. Eat more foods harvested from underground. Generally, above-ground foods such as Chinese cabbage and chives encourage yang qi to rise, whereas sweet potatoes, potatoes, Chinese yam, and other underground foods help store it. Modern environments, work, and habits — including more nightlife — generally cause excessive outward rising of yang qi. Deliberately eating more underground foods helps conserve it and prevents excessive depletion.

Modern diets have two excesses and two deficiencies: too many refined grains and too few coarse grains, too much above-ground food and too little underground food. This imbalance should be corrected.

2. Chinese medicine classifies foods through the five phases and five colors, an approach helpful in daily health cultivation and increasingly supported by science. Modern experiments show that yellow vegetables have a special benefit for stomach health. Five-phase theory assigns the spleen and stomach to earth, whose corresponding color is yellow; yellow enters the spleen and stomach.

Following the principle that “Everything born in nature has its use,” the five colors and flavors correspond to the internal organs as follows:

Blue-green and sourness enter the liver. The liver belongs to wood and is closely associated with the gallbladder.

Red and bitterness enter the heart. The heart belongs to fire and forms an interior–exterior pair with the small intestine.

Yellow and sweetness enter the spleen. The spleen belongs to earth and forms an interior–exterior pair with the stomach.

White and pungency enter the lungs. The lungs belong to metal and form an interior–exterior pair with the large intestine.

Black and saltiness enter the kidneys. The kidneys belong to water and form an interior–exterior pair with the bladder.

Choosing foods by color, flavor, and bodily need is another method of cultivating health.

3. Do not eat when angry; eat slowly when troubled. Do not rush when hungry; avoid cold food on an empty stomach. Anger and worry disrupt the coordination of internal organs, particularly the liver’s contribution to gastrointestinal digestion. Food eaten then is difficult to digest and, in severe cases, causes illness that is hard to treat.

Throughout history, many illnesses have arisen from eating while angry or worried. When upset, first drink some water; wait until the distension in the chest and abdomen subsides before eating.

Never eat cold food when hungry, lest it injure the spleen and stomach. Those of middle age and above, whose spleen and stomach are weaker, should be especially careful.

Among cold cooked staples, ordinary and sticky rice are particularly harmful. Rice flowers at night and closes at sunrise, making it yin and cool in nature. Traditionally, women in northern China were not allowed rice during the month after childbirth. Wheat flowers at sunrise and closes at night; it is yang and neutral, so wheat foods were permitted during postpartum confinement. Millet congee, meat broth, and fruit juice are recommended during this period. Eating cold cooked rice while hungry often leaves lasting stomach trouble.

An old Chinese folk remedy treats a stomach injured by cold rice by roasting the same rice on a roof tile until golden-brown, grinding it, and taking it with yellow rice wine. Alternatively, stomach-strengthening Chinese medicine may be taken immediately with ginger-and-sugar water.

4. Some people routinely take calcium and assorted nutritional supplements without a particular need, only to become more depleted, accelerate osteoporosis, and worsen physiological function. A little supplementation is acceptable; too much creates trouble. Substances that cannot be absorbed become a burden within the body. What should be done? Increase exercise. Even if calcium or other nutritional deficiencies seem severe enough to require supplementation, these biochemically synthesized nutrient tablets should not be used.

Exercise can improve bodily functions, including digestion and absorption. To replenish calcium, buy bones and make broth, preferably adding a pig’s trotter. Trotters nourish yin and contain abundant gelatinous material and protein. Bones need this gelatinous material. Such broth contains calcium and other needed nutrients; readily absorbed, they gradually penetrate the bones. Bones and skin particularly require gelatinous substances. Deficiency can lead to osteoporosis and dehydrated, lax skin; adequate supplies prevent these changes.

People short of calcium may also eat more pig’s trotters stewed with soybeans, preferably adding marrow bones to make a concentrated broth. Have less rib broth and more spinal-bone broth; spinal bones are cheaper too. The most nutritious part of the spine is the tailbone region. Simply making broth from bones and tailbones is a better way to replenish calcium.

Pay attention to dietary composition, arrange food and daily living sensibly, and understand and master this culture of health cultivation.

Finally, a common misunderstanding deserves attention: when broth or thoroughly stewed meat is inconvenient or unavailable, some people stop eating meat altogether. For example, work may oblige them to eat workplace meals, whose meat has not been stewed until tender, let alone simmered overnight into broth. Eating it brings meat toxins, so what do they do? They eat only rice and vegetables for long periods. This merely exchanges one mistake for another, is inadvisable, and causes malnutrition.

To obtain good nourishment with little or no meat toxicity, follow the ten principles. If that is impossible, continue eating pieces of meat, but in smaller quantities and with more plant food. Animal fat is best avoided. At home I mainly drink broth, occasionally stewing chicken feet or pig’s trotters, removing the floating fat, and eating both meat and broth at lunch. But only at lunch: in the evening I drink broth alone.

Health cultivation should be applied flexibly to actual circumstances, without rigid adherence.

3. Rest After Lunch to Nourish the Spirit: The Third Principle

A midday nap is very important. Rest briefly after lunch, then take a nap and make it a daily habit. As the ancients said, “Rest a little after eating to nourish the spirit.”

During the wu period, 11 a.m.–1 p.m., the heart meridian is most active. A short sleep then greatly benefits the heart: “When one lies down, blood returns to the liver.” The heart governs consciousness, opens into the tongue, and manifests its radiance in the face. A nourished heart naturally produces a bright appearance. Chinese medicine says that “The heart and spirit communicate.” Sleeping then for 15 minutes or more nourishes the heart, soothes the spirit, and enriches qi and blood, hence the name “beauty sleep.” During wei, 1–3 p.m., the small-intestine meridian is most active. “The heart and small intestine form an interior–exterior pair.” A midday nap replenishes heart qi, supporting nutrient absorption during wei and helping the skin remain rosy, smooth, and clear.

Women unaccustomed to napping can notice a prompt improvement in their facial skin after maintaining the habit for a time.

Do not nap too long. Around 45 minutes is generally appropriate. For busy younger people, even 15 minutes of actual sleep offers substantial benefit; older people should generally not exceed an hour. Schedule the nap during wu, 11 a.m.–1 p.m.

From the perspective of yin and yang generating one another and the unity of humanity and nature, wu and zi have special significance for human life and health among the day’s 12 two-hour periods.

Traditional Chinese culture contains the taiji diagram, which expresses in the simplest form the fundamental laws of movement and development in the universe. Accounts differ as to when, where, and by whom it was created. One thing is clear: it is a masterpiece of five thousand years of Chinese civilization and embodies the philosophical essence of that culture. It also has the practical value of “four liang moving a thousand jin”: solving the most complex problems by the simplest methods and obtaining the greatest benefit with the least investment.

The diagram shows that everything in the universe is a unity of opposing forces, bearing yin and embracing yang, constantly moving, changing, and developing. As one side reaches its extreme, its opposite has already begun changing alongside it. The brightest part of the yang half, or yang fish, contains a dark dot; the darkest part of the yin half contains a bright dot. Each contains the other, expressing the principle that extreme yang gives birth to yin and extreme yin to yang. They embrace and generate one another in endless cycles.

Everything under heaven follows this pattern.

The ancient sages believed that heaven, earth, and humanity originate in one qi and that all things are connected through it. Visible forms are simply condensed states of qi. Within and around them exists a formless qi field, so minute that nothing lies inside it and so vast that nothing lies outside it. Thus even the smallest object’s qi field extends throughout the universe. Through these fields, all things blend, unite, and respond to one another, presenting a vision of “all things as one.” These fields are also their principal means of mutual connection and influence.

Traditional yin–yang theory holds that yang is formless and yin has form. Accordingly, the visible aspects of things are yin, their invisible qi fields yang. Form and formlessness contain one another; yin and yang embrace and generate one another, forming complete unities, each a complete taiji. The saying “Each thing is born with its own body, and each body contains its own heaven and earth” expresses this idea. The human body, too, is a small taiji, a miniature universe.

Truly understanding the taiji diagram reveals the solar system — heaven and earth — as a great taiji, the entire universe as an even greater one, and each thing as a smaller taiji. Each is integrated into the larger taiji of nature and the cosmos, blending, uniting, and responding. This naturally presents the unity of humanity and nature. The human taiji likewise forms one whole with heaven and earth. Within that whole, changes in nature’s yin and yang bring corresponding changes in the body’s miniature universe.

In other words, natural changes in yin and yang regulate and influence bodily changes. This is what the ancients called “the correspondence between humanity and nature.” Modern science also demonstrates that cosmic movement is holistic and every object belongs to the universe. More than two thousand years ago, the Huangdi Neijing revealed this wholeness and the connection of all things through one qi, establishing the great theories of “the unity of humanity and nature” and “the correspondence between humanity and nature.”

Traditional culture deserves renewed study, understanding, and appreciation. A prominent American sociologist observed that Western society’s survival would depend on whether it could absorb these Eastern, and above all Chinese, ideas. This would be a cultural revolution in the true sense.

Zi is the period of nature’s most extreme yin. Extreme yin generates yang, so this is when the first yang returns in heaven and earth. In correspondence with nature, the first yang also arises in the human body. Bodily yang qi enters a phase of gradual growth, but growth requires it first to return to the body and its root. Only by being concealed and stored can it rest, recover, and increase. At this transition between yin and yang, when the first yang returns, it therefore needs careful protection through peaceful sleep and quiet nourishment.

From zi through chou to the beginning of yin — 11 p.m.–3 a.m. — is the most precious time for yang qi to return to its root and gradually grow. Observe everyday life: people deficient in yang become more deficient after staying up late, with bluish, darkened complexions the next day. Sexual activity during zi, when the first yang returns, noticeably damages their health and inevitably shortens life. Night workers should rest briefly during zi whenever possible; if unable to sleep, close the eyes for a while. This greatly benefits the body, as those who practice it will discover.

Only when this return of yang and transition between yin and yang succeeds can the next cycle of their mutual embrace and generation proceed smoothly. At the beginning of yin, the body moves from the concealed growth of yang qi into its outward rising. When this reaches a certain point, a person wakes naturally. After yin, at around 5 a.m., one should therefore awaken and begin the day’s activities. This is a natural process of life.

Only when yang qi is properly stored and nourished at night can it rise well by day, giving strength and mental clarity during waking hours.

At wu, the sun is overhead, yang qi is strongest, and nature reaches extreme yang. Extreme yang produces yin, so the body and nature together enter another transition: the birth of the first yin. This newly emerging yin likewise requires care, which is why one should take a brief midday nap or rest. Proper midday rest leaves a person energetic and clear-minded throughout the afternoon and even into the evening.

Sleep therefore has different effects at different times. Zi and wu are transition points for yin and yang, and for the movement of qi, in both nature and the body. Among the day’s 12 periods, sleep during these two is most important. Good zi and wu sleep provides the greatest health benefit for the smallest investment of time.

The Chinese habit of a midday rest is thus both healthful and wise. Newspaper articles claiming it offers no health benefit reflect a failure to understand yin and yang.

Just as the body has moments when the first yang and first yin arise within each 24-hour day, nature has corresponding solar terms within the year.

The winter solstice, in the eleventh month, marks nature’s return of the first yang. The ancients considered it a day for closing the gates and withdrawing. In the Book of Changes, the Return hexagram consists of Kun above Zhen, earth above thunder. Its Image says, “Thunder within the earth: Return. On the solstice, the former kings closed the passes; merchants and travelers did not journey.” Here “the solstice” means the winter solstice. Why withdraw then? It is when the year’s first yang emerges and returns to its root. Withdrawal has two purposes. The first is to reduce human activity and avoid disturbing this natural transition.

Northern farmers fear winter thunder. Why? It means nature’s yang qi has been disturbed and is rising when it should return to its root, remain concealed, and grow. When spring comes and it should rise, insufficient strength remains, leading to poor harvests. The second purpose is “to draw on heaven’s strength to replenish human strength.” Thus the ancients withdrew at the winter solstice, shutting out toil and disturbance. In a quiet setting, the body could resonate with nature and use its strength to return yang qi to its root, nourish life, and increase vitality.

The ancients also withdrew at the summer solstice, when the first yin begins to grow. The Biography of Lu Gong in the Book of the Later Han states: “According to the Changes, the fifth month has its governing influence; the former kings issued orders stopping travel in every direction.” The summer solstice falls in the fifth month. Withdrawal was therefore required both when yin gives way to yang at the winter solstice and when yang gives way to yin at the summer solstice.

Carefully protecting yin and yang as they first emerge at these natural transitions brings twice the benefit for half the effort in health cultivation.

4. Drink Fruit Juice After Resting to Nourish the Blood and Vessels: The Fourth Principle

Wu is followed by wei, 1–3 p.m., the period entered after a midday nap. Drink fruit juice then: it is the time to nourish the blood and vessels and replenish vitamins. As the ancients said, “After a short rest, drink fruit juice to nourish the blood and vessels.”

Fruit juice leaves the stomach about 10 minutes after being drunk and enters the small intestine, whose lining immediately absorbs it into the bloodstream. In other words, its nutrients are absorbed entirely by the small intestine. During wei, 1–3 p.m., the small-intestine meridian is strongest. The small intestine separates the pure from the turbid, directing fluids to the bladder, waste to the large intestine, and essence upward to the spleen, which governs blood. Juice at this time supports metabolism and purifies the blood. This is why wei is chosen.

There is another reason. During the following shen period, 3–5 p.m., the bladder meridian is most active. The bladder stores water and bodily fluids, circulates them, and expels the excess. Shen is the time for draining fire and expelling toxins; urination, exercise, and perspiration then favor their removal. Modern science has also found that body temperature, internal fire, and metabolic rate peak at 4 p.m. Juice during wei, 1–3 p.m., therefore both nourishes the blood and vessels and replenishes water. If you do not drink juice, remember to drink water instead.

This allows substantial urine to collect for elimination during shen and prevents dehydration during exercise, facilitating perspiration and the discharge of fire and toxins.

Leave about one or two hours between lunch and fruit juice. Drinking it immediately after eating dilutes food in the stomach and impairs digestion and absorption. Adults may drink from three or four liang, about one glass, to around one jin, about two glasses, at a time. Fresh juice from neutral-natured fruits is a healthy drink. Besides taking it during wei to nourish the blood and vessels, it may be drunk on an empty stomach after work in the afternoon.

Would eating fruit directly not be more convenient? Yes, but only on a completely empty stomach. Leave at least two hours after lunch. For most people, food requires at least two hours of digestion before gradually leaving the stomach. Fruit eaten while food remains there mixes with it and becomes held up. If the fruit pulp stays too long, it ferments with the food, creating new waste and making digestion and absorption harder. Severe cases may cause bloating, diarrhea, and other adverse effects.

Many now regard fruit after a meal as an ideal feature of modern living and enjoy it to freshen the palate. In fact, this is an incorrect habit. Those who do not drink juice are advised to eat an apple on an empty stomach in the afternoon, effectively preventing high blood lipids and other modern diseases.

The body also absorbs and utilizes juice more efficiently than whole fruit. Teeth cannot grind fruit extremely fine; they merely break it into small pieces. Its nutrients are consequently not fully absorbed by the digestive tract, making whole-fruit consumption a form of waste. Whenever circumstances permit, favor juice.

Do not buy ready-made juice merely for convenience, because it is not sufficiently fresh. A juicer makes home preparation easy. Different fruits have different medicinal properties and should be chosen accordingly. Watermelon, like banana, is cold in nature and particularly injurious to the spleen. Cucumber and tomato are cooling and should not be eaten raw in excess. The safest juices come from neutral fruits such as apples, grapes, and sweet oranges. Healthy people may eat watermelon in hot weather to relieve summer heat and clear fire, but eating it even in winter, as people now do, disregards the proper order.

An important principle is always to prioritize protecting the original qi of the spleen and kidneys and the body’s yang qi. As the foundation of postnatal nourishment, the spleen and stomach require careful protection; damage to this foundation allows all manner of illness to arise. Limit raw consumption of cold or cooling fruits and vegetables. People with very weak spleen and stomach function or qi deficiency should temporarily avoid fruit and juice, waiting until they regain some strength before benefiting from them. Those with weak spleen function should place juice in warm water during winter and drink it slightly warmed, preventing cold from injuring the spleen. The water should not be too hot, lest it destroy vitamins.

Spleen and qi deficiency weakens the body’s ability to transform food. Raw and cold foods, especially those cold or cooling in nature, can further damage the spleen, stomach, and yang qi, worsening weakness. Incompletely transformed food becomes new internal waste. People recovering from serious illness and women after childbirth should be especially careful. Some dismiss this and suffer for it. A friend of mine followed a modern nutritionist’s advice and ate fruit for breakfast every morning.

After half a year, the friend’s gums had receded and physical condition had deteriorated considerably. Prolonged spleen-qi weakness causes upper-gum recession; prolonged stomach-qi weakness causes lower-gum recession.

If juice causes diarrhea or soft, loose stools, stop temporarily and switch to warm or hot boiled water. Avoid juice when stools are ordinarily loose, even juice of neutral nature. If strongly desired, boil it before drinking. With stomach fire and dry stools, some cooling fruit or more juice may be appropriate.

Besides morning cooled boiled water, drink some water half an hour before lunch and remember to replenish fluids during the afternoon. Avoid excessive water before bed so that sleep is not disturbed. From the standpoint of health cultivation, most people today are short of water. Why drink half an hour before eating? Once water dilutes gastric juices, roughly half an hour is needed to secrete enough fresh juice for proper digestion and absorption.

Water is therefore unsuitable within the half-hour immediately before a meal, a point made in the first principle and emphasized again here. A few sips to moisten the throat are, of course, acceptable.

What if someone likes neither fruit nor juice? They should still drink water in the afternoon and avoid overcooking vegetables prepared with water or broth, although people with weak spleen function should favor cooked food. This will generally meet basic vitamin needs.

Vegetables and boiled water cannot completely replace fruit juice, however. Juice does more than supply vitamins: its distinctive benefit is nourishing the blood and vessels, best achieved during wei. After drinking it daily for a time, the skin gradually becomes fairer and clearer, presumably because the blood has been purified. The ancient understanding that the small-intestine meridian is strong at the start of wei and juice then nourishes the blood and vessels appears correct. Ancient wisdom deserves serious consideration. I suspect women and those who value their appearance will be especially likely to follow this principle after reading the book.

Many people complain of daily fatigue. Is work exhausting? Not necessarily. Is their food poor? Not necessarily. What, then, explains it? Besides insufficient animal protein, vitamin deficiency is common. Why should people who eat plenty of vegetables lack vitamins? Because vegetable vitamins exist only in the raw state and disappear on cooking.

Juice may also be taken at other times, such as in the evening, preferably on an empty stomach, to relieve thirst and supply vitamins. Moderation still matters. Excessive consumption of any edible substance harms the spleen and stomach.

Remember that the ten principles form a complete system; following only one can sometimes cause problems. Fruit juice tends to be cooling, while broth tends to be warming. Juice alone can discomfort those with weak spleen and stomach function; broth alone can cause internal heat in sensitive people. Taking both avoids these drawbacks. Those who follow all ten principles strictly can achieve balanced qi and blood and steadily improve their constitution.

5. Move and Perspire During Shen: The Fifth Principle

Exercise during the afternoon shen period, 3–5 p.m. The bladder meridian is then most active. This important, extensive pathway runs from the heels along the backs of the calves, up both sides of the spine, and into the brain. The bladder stores and circulates water and bodily fluids, expelling the surplus. Shen is the time to drain fire and expel toxins; exercise, perspiration, and urination then support metabolism. As the ancients said, “During shen, move until you perspire, and take pleasure in calling out.”

Around 4 p.m., metabolic rate is highest, energy and judgment are better, and exercise is less likely to cause injury. Some may say, “That is precisely when I feel unwell.” This indicates a problem; pronounced drowsiness then is kidney-yang deficiency. Exercise is not solely a morning activity. Shen, especially around 4 p.m., is best for relatively strenuous exercise. In the twelve-animal zodiac, shen corresponds to the monkey, which leaps about — another indication of the period’s suitability for movement.

Morning activity need only stretch and loosen the body, free the sinews and channels, and encourage yang qi to rise. Gentle activities such as walking outdoors, jogging, and tai chi are best. Afternoon exercise may be more substantial: “move until you perspire.” Whatever form you choose, emphasize aerobic activity. Since the bladder meridian is strongest during shen and the body is draining fire and toxins, perspiration then is desirable and has a pronounced strengthening effect. If thirsty after sweating, drink boiled water near body temperature rather than refrigerated water for momentary pleasure.

During the three winter months, however, exercise less and avoid excessive sweating, especially a heavy sweat, lest upright qi be injured. Many people now take frequent hot baths or saunas in winter, deliberately sweating profusely each time. This inevitably damages yang qi and is unfavorable to health cultivation. Once you understand this, leave a winter bath when the whole body is warm or lightly perspiring. That is the proper approach. Massage and vigorous back-scrubbing in winter can also damage qi and the body.

Gentle massage replenishes qi; forceful massage drains it. Do not casually seek out so-called blind massage services: their forceful techniques may feel good at the time, but fatigue soon afterward is an inevitable result. Truly beneficial massage is gentle and follows the meridians; it should not leave you feeling beaten up.

Unfortunately, few massage practitioners today truly understand their craft.

“Age begins in the legs; death comes through the mouth.” Compared with younger people, older adults particularly need afternoon exercise and activity for the legs and feet, which strengthens the kidneys. Hill walking, brisk walking, and jogging are good choices. Everyone has preferred activities: swimming, martial arts, gym workouts, badminton, and table tennis are all good. These are conventional methods available to everyone, requiring little specialized technique yet delivering clear benefits. The key is persistence.

People in good physical condition may add appropriate exercise with weights, which can noticeably improve heart and lung function. If daily life seems too busy, simply set aside half an hour.

During ordinary exercise, make a sound if you can rather than remaining silent: “take pleasure in calling out.” Vocalization helps clear qi rise and turbid qi descend. This explains the generally long lives of some Peking opera performers and singers. Peking opera emphasizes projecting the voice from the dantian. In less than half an hour, qi and blood circulate freely and the whole body perspires, with greater fitness benefits than running 2,000 meters. Two years ago, after a friend’s father retired, I explained some health-cultivation methods to him. He now climbs a hill every morning and afternoon and practices vocalization at the summit. Calling out from a height not only raises clear qi and lowers turbid qi, but strengthens the five viscera; while calling, retain some awareness inside the body and observe its sensations. He can now project his voice a great distance, showing that his central qi is abundant.

Once troubled by many illnesses, he now has none of them. Many notable figures in ancient times also enjoyed climbing hills and letting out long calls audible several li away. “Taking pleasure in calling out” has another meaning: exercise in a cheerful frame of mind.

Walking is an excellent exercise, provided it is brisk and the strides are long. Two or three kilometers in the morning or early evening gives clear benefits. While walking, direct all your attention to your legs. The spirit mobilizes qi, which mobilizes essence and bodily fluids, directing them into the leg joints to lubricate them. This is why skilled walkers can travel far and long without aching, tired legs. Walking is the most economical exercise: it costs nothing, rarely causes serious problems, and particularly suits middle-aged and older people.

Those with irregular schedules can still obtain good results by exercising in the afternoon at least twice a week. Busy people may choose either morning or afternoon; establishing a habit is what matters. When circumstances permit, exercise a little both morning and evening every day.

Points to Observe

First, exercise moderately. Begin with a manageable amount and progress gradually. Many people either do nothing or suddenly undertake more than an hour of intense exercise, causing harm rather than benefit.

“Life lies in movement” is a familiar saying. Adding “moderate” makes it more accurate: “Life lies in moderate movement.” Excess exercise depletes yang qi and damages the body. The purpose of everyday exercise is health and longevity, not winning a world championship. When walking, continue while the legs and feet feel light; rest as soon as they become a little tired. Middle-aged and older people should be especially careful. Fatigue afterward indicates excessive exercise.

Some older and middle-aged people buy gym memberships only to develop heart problems rather than improve their health. This occurs because depleted yang damages the qi of the sinews, resulting in “the sinews failing to nourish the heart.”

Markedly weak middle-aged and older people should avoid vigorous afternoon exercise. Their capacity to generate yang is poor and their bodily fluids are depleted, so excessive movement consumes more yang than it produces and wears the joints. Instead, go outside in the morning to move gently and breathe fresh air; in winter, wait for sunlight. Vital qi sprouts in the liver, which corresponds to spring and governs the sinews. Morning is the day’s spring, and spring governs movement. Going out for a slow walk frees the sinews and channels, allows liver qi to unfold, and renews vitality.

Generally, weak people should avoid strenuous exercise. At first, simply loosen and stretch the body, preferably by walking or jogging. Stop before feeling tired; retaining thirty percent of your strength allows the body to benefit. Increase duration and intensity gradually as health improves: that is a scientific approach. When beginning afternoon exercise, choose an appropriate amount, progress steadily, and avoid noticeable fatigue afterward. Alongside this, eat coarse grains and take meat broth or tender stewed meat and fruit juice, so the body can become truly strong.

Younger people may exercise more intensely.

Second, once it is fully dark, exercise — particularly strenuous exercise — is unsuitable. Everyone knows the saying “Go out early and return in the evening.” Morning corresponds to spring; spring governs yang, and yang movement and outward activity. Morning exercise promotes yang qi. Evening corresponds to autumn, which is yin; yin governs inwardness and stillness. Reducing activity after dark conserves yang qi. In the countryside, birds return to the trees as darkness approaches: later in summer, earlier in winter, following a regular pattern.

We should learn from them. When should daily activity decrease? Let darkness be the guide. This generally coincides with you, 5–7 p.m., when the kidney meridian is strongest according to the midnight–noon flow of meridian qi. It is the day’s autumn. After the discharge of fire and toxins during shen, the kidneys begin storing essence during you. Autumn governs gathering; without gathering there is no storage, and essence is lost. After 9 p.m. the day’s winter begins. Winter governs storage, and stimulating activity afterward disturbs and disperses yang qi.

“When yang qi is troubled by toil, it expands.” Here expansion means outward movement. At night, yang qi should draw inward and return to its proper place. Agitation and exercise prevent that return, causing gradual depletion. After 9 p.m., therefore, rest and sleep. Going to the gym after dinner when it is already fully dark, as many now do, violates the laws of life. A post-dinner stroll may aid digestion, but during the three winter months keep outdoor activity after dark to a minimum, in keeping with winter’s principle of nurturing storage.

Although shen already belongs to the day’s autumn, it is the time for draining fire and expelling toxins, so some activity benefits metabolism. After shen, strenuous conventional exercise is no longer appropriate.

We have discussed exercise’s importance and why ill or weak people must be cautious. Movement can both generate yang and consume it. Which effect prevails depends on the individual’s condition.

We actually consume yang continuously. Speaking and thinking use it; walking uses both yang and qi. But with a sound foundation and normal yang-generating function, it is quickly replenished. Movement then generates yang, improves its circulation, and stimulates its production. Even so, moderation remains essential, and the principle “Do not exhaust yourself recklessly” must always be observed.

Weak people should not overexercise; walking is generally sufficient. Traditionally, Chinese medicine recommends quiet recuperation for the profoundly weak. Their capacity to generate yang is inadequate. Excess movement consumes more than it produces, steadily depleting yang qi, the basis of life, and undermining life’s foundation.

A relative of mine was extremely weak after a serious illness. During a visit I explained some basic convalescent care. He followed it, recovered well for a time, and was delighted. When we next met, however, his complexion looked wrong, so I asked what had happened.

He said, “I’ve been exercising these past few days: running 2,000 meters every morning and playing table tennis in the workplace gym in the afternoon. Perhaps I’m not used to it yet, but I keep feeling exhausted and sleepy.”

I replied, “You’ve got it wrong! This isn’t helping your body. You’re too weak; stop overtaxing yourself and recuperate quietly. Go to bed and get up early, and simply stroll around your residential compound in the morning. Wait more than half a month before running again, beginning with about 500 meters of slow jogging. If you feel even slightly tired afterward, reduce the amount; increase it only if you feel well. Play less table tennis for the next few days and avoid strenuous exercise. Be patient — your constitution will improve.” He listened, and after two or three months was considerably healthier and stronger.

One Final Point on Exercise

There are many forms of exercise, operating at different levels. Certain distinctive methods rooted in Chinese health-cultivation culture are better than any described above. Their defining feature is directly strengthening internal-organ function and replenishing original qi. Vital qi originates in the internal organs, not the limbs. Conventional exercise excels at strengthening muscles but affects the organs only indirectly, making its contribution to organ function less than ideal.

Directly strengthening the organs would produce more noticeable bodily changes and better results. Yet simply publishing such methods in a book would inevitably create problems, and some readers would neither accept nor agree with them. They are best learned through personal instruction or through reading supplemented by instructional video discs, reducing the chance of error. Their requirements and principles differ from those of conventional exercise, so discussing both together would cause confusion.

I mention these methods here because I may publish a book and video discs about them in the future; consider this an advance indication. When using conventional exercise, the points in this section are sufficient. Be sure to observe the principles set out here.

6. Sleep on an Empty Stomach to Dispel Fattening Qi and Nourish Stomach Qi: The Sixth Principle

Eat little or no dinner and keep the stomach empty during sleep. I summarize this as “Sleep on an empty stomach, dispelling fattening qi to nourish stomach qi.”

Remaining full throughout the day readily leads to illness. This is why the Chinese did not traditionally eat dinner as people do now. The evening meal was called an “evening snack,” meaning only a little food. One reason modern people fall ill so frequently is that they overfill themselves at dinner. Experience demonstrates that skipping dinner does not harm health; instead, the strong hunger it induces makes illness less likely. Modern medicine also holds that some portion of every 24-hour day must be spent hungry, with an empty stomach, to awaken the body’s inherent powers of self-healing and immunity.

Dinner should be nutritious and easy to digest. Recommended evening foods are nourishing congee, meat broth, soy milk, rice water, and easily digested vegetables. Millet, corn, or japonica-rice congee prepared with chicken broth, another meat broth, or soy milk is especially nutritious. Tastes differ: some prefer congee made simply with water. Options include millet congee, millet and sweet potato, japonica rice, japonica rice and sweet potato, or ordinary rice and sweet potato. Note the distinction between congee and merely watery rice: prolonged cooking should blend the grain and water together so the body can absorb them readily.

Older people and children have weaker spleen and stomach function and should particularly favor congee in the evening, adding meat broth if concerned about nutrition. Coarse grains are difficult to digest, so avoid ordinary coarse-grain meals at night except in congee form. Easily digested vegetables are acceptable. Those who do not drink juice may eat raw vegetables mixed with toasted sesame paste in the evening, chewing them; this can avoid spleen injury and diarrhea. Hunger generally returns within an hour or two, yet the nourishment is better than that obtained through overeating.

In fact, developing the habit of eating nothing in the evening is still healthier. Buddhist and Daoist practitioners once observed this rule, and people in many regions of China and abroad also forgo dinner. Some ask whether nighttime hunger will cause stomach disease. It will not; the key is establishing a habit. As the ancients said, “A time for tension and a time for relaxation: this is the way of Kings Wen and Wu.” After working hard all day, the stomach should rest at night; that is how stomach qi is nourished. What it most fears is irregular, unrestrained eating. Alternating between eating and not eating, or between large and small dinners, readily causes stomach trouble.

Forgoing dinner is best, but most people find the idea difficult to accept. I therefore currently recommend eating a little in the evening. Keep it nutritious, easily digested, regular in time, and consistent in quantity; this can nourish the stomach. People with existing stomach disease who feel discomfort when hungry at night may take a small bowl of warm congee or broth, avoiding difficult-to-digest foods. Even congee and hot broth should leave one only half full, never completely satiated.

What does “dispelling fattening qi” mean? A saying goes, “A horse will not grow fat without nighttime fodder.” People are the same: without a large evening meal, they do not become obese. Nowadays most people are too fat. In the United States, reportedly around 60% are overweight, yet Americans do not eat especially large portions. Why? They enjoy dinner and late-night snacks. These cause weight gain because little energy is consumed during sleep, allowing abundant incoming calories to become fat readily.

This fat accumulates, first filling out the abdomen and then enlarging it further. It also gathers elsewhere — under the skin, in the blood, heart muscle, and liver — impairing bodily function.

A modest dinner soon leaves you hungry. After a while, however, hunger passes: the body has begun consuming itself. Excess fat gradually disappears and you become slimmer. Surprised acquaintances ask which weight-loss drug you have taken. You can reply that heaven’s secrets must not be disclosed.

Some say a small dinner may suit office workers and older people, but not the young or manual workers. That is wrong. Many residents of Rudong County in Nantong, Jiangsu, still eat the traditional two congee meals and one solid meal daily; manual workers remain energetic too. The county also has far more centenarians proportionally than other Chinese cities. Is this surprising? No: the pattern largely matches the dietary requirements of health cultivation. Some people today neglect lunch and never exercise after returning from work. Instead, they spend considerable time preparing a lavish dinner and gorge themselves in the name of “replenishing nutrition.” They are actually inviting illness.

Without evening hunger, the body cannot carry out qi transformation properly. How could illness not follow?

What is bodily qi transformation? Every day, substantial dead tissue disappears within the body. Chinese medicine calls this process qi transformation; it is one aspect of it, just as food digestion and absorption are others. Western medicine calls it absorption. Many people have experienced hunger fading when they do not eat immediately. What is happening? Chinese medicine calls this qi transformation: the body begins consuming itself. Overweight people become thinner, masses shrink, and accumulated fluid decreases.

Such is the remarkable nature of qi transformation.

Because this process works well during hunger, one must allow oneself to remain hungry rather than eating at will. Generally, people need only two daytime meals. Those doing strenuous manual labor may add a meal around 3 p.m., as happens during busy farming seasons. Eating little or nothing near bedtime preserves an empty stomach to optimize transformation during sleep. Nutritionists now also suggest fasting one day each week to help absorb dead material within the body; the reasoning is the same.

A full day without food can, however, provoke gallstones, so complete fasting for that day is not scientifically sound.

Many people eat to their heart’s content whenever evening hunger arises, even during the night. This very poor habit prevents proper qi transformation. Yet many dismiss such advice and eat their fill whenever hungry at night, sacrificing the body for the mouth.

We notice changes in the body on waking because qi transformation has occurred during sleep. Why does a hematoma after a fracture disappear without a doctor removing it? It has been transformed. Why does a badly swollen hand after a hornet sting subside without the doctor clearing the local swelling? The swelling has been transformed.

How Does Western Medicine Explain Qi Transformation or Absorption?

Western medicine identifies immune cells in the blood called phagocytes. They are the body’s scavengers, specializing in consuming dead cells; this is nonspecific immunity. There are two forms of immunity: nonspecific immunity, represented by phagocytes, and specific immunity, represented by special blood proteins called antibodies. Antibodies constitute immunity acquired after an infectious disease. Western medicine uses this principle in vaccination.

There are thousands of infectious diseases, however. No person can receive thousands of vaccines, and some antibodies do not persist indefinitely. Human immunity therefore depends chiefly on nonspecific immunity — phagocytes.

Modern medicine has found that the strength of nonspecific immunity depends on phagocyte numbers and activity. Their number depends on nutritional status, while their activity depends on hunger.

Phagocytes approach and consume dead material, digesting it inside themselves; this is called pinocytosis. This process is the feeding method of single-celled animals. Paramecia, amoebae, and other single-celled organisms still feed this way. As animals evolved, they began using mouths, esophagi, stomachs, and intestines, but blood phagocytes retained pinocytosis.

This self-cleaning function is essential. Without it, dead tissue would pile up inside the body.

Adults shed large numbers of cells daily, almost all of which are consumed by phagocytes and digested into organic material. The phagocytes then undergo self-dissolution, also becoming organic material usable by other cells. They therefore consume large quantities of dead tissue each day. They can eat dead cells but not healthy ones. Interestingly, microscopic photography shows that when a person is intensely hungry, several blood phagocytes attack dead cells like starving wolves, tearing them apart and eating them.

When hunger is weak, however, phagocytes and dead cells largely pass one another without interacting.

This explains the particular emphasis on improving stomach qi by omitting dinner. Without strong hunger, neither the person nor the phagocytes eat. Conversely, when a person eats like a starving wolf, phagocytes consume dead cells in the same way. A fracture-related hematoma disappears quickly in someone with good stomach qi, slowly in someone with poor stomach qi. The same applies to swelling from a hornet sting. Many readers may recognize this from experience.

The disappearance of cancerous masses follows the same principle: faster with good stomach qi, slower with poor stomach qi.

The point is not that one is incapable of eating a full dinner. Rather, eating less optimizes qi transformation and supports proper metabolism. A rumbling, hungry belly signals that the digestive tract has entered a good transformative state, when food nutrients are best absorbed. The ancients called this “eating when the intestines rumble.” If one does not eat, hunger fades after about two hours and the whole body can enter a favorable state of transformation.

Sleeping then brings good-quality rest and an energetic, clear-minded morning. This is “sleeping on an empty stomach.” Go to bed immediately after a full meal, and you will feel exhausted the next day; try it yourself if unconvinced. Those who eat late-night snacks daily inevitably experience a worsening constitution.

Conversely, you may eat a full dinner, provided the stomach is already empty by seven or eight in the evening if bedtime is 9:30 p.m. As the saying goes, “A half-grown boy can eat his father out of house and home.” Some adolescents can digest this quickly; we cannot. Even adolescents, however, should eat dinner only to seventy percent full. If very hungry later, they should take liquids such as meat broth, juice, soy milk, or nourishing congee. School cafeterias providing these in the evening, while preventing students from eating packaged foods, would noticeably improve students’ constitutions in less than a month.

This is why nourishing congees, broth, juice, and soy milk can supply evening nutrition: only these foods ensure digestion is largely complete within about 1 hour, with high nutrient absorption. Most people eat large dinners that are not fully digested until the early morning, and most of their food is poorly absorbed, “overworking the digestive tract and wasting money.” Others eat little but choose difficult foods such as rich meat and fish dishes or sticky rice. Digestion is still underway at bedtime, leaving them tossing and turning.

Remember: for health cultivation, wait until the whole body enters a favorable transformative state — after the hunger has passed — before sleeping. This is the bodily secret involved.

Many do not realize that poor sleep relates to food remaining in the stomach. A large nighttime meal directs all energy toward processing it. Qi and blood concentrate in the stomach, leaving other areas undernourished. The brain, in particular, lacks their nourishment, preventing easy or deep sleep. We sleep most deeply only when yang qi, qi, and blood are abundant and harmonious. Do not underestimate this principle.

Sometimes an insomniac who follows it reports, “I now sleep like a baby.” This delights me, because it indicates a truly high and deep quality of sleep, which is very important. Remember: when the stomach is out of harmony, sleep is restless. Be sure to eat less at night.

A Western saying advises, “Give your dinner to your enemy.” Its meaning is plain: let the enemy die sooner. Another says, “Eat lunch like an emperor and dinner like a beggar.” The ancient Chinese said, “Overeating injures the body; hunger treats a hundred diseases.” Skipping dinner will not starve a person to death, but excessive dinner can damage them through overfilling. This is basic health-cultivation knowledge. Children in particular readily develop fever after overeating in the evening.

Even young people who eat a very full dinner readily have nightmares that harm the brain. Older people, especially, are prone to sudden death after an excessive evening meal.

Without observing this principle, one cannot claim to practice health cultivation properly.

7. Bathe the Feet in Hot Water Before Bed to Warm the Meridians and Raise Clear Qi: The Seventh Principle

Bathe the feet in hot water before sleeping. This has special significance for health and longevity. What exactly are its benefits?

First, it can prevent sudden death. As the ancients said, “Bathe the feet in hot water before bed, warming the meridians so clear qi rises; when clear qi rises, death does not occur.” People, especially older adults, are prone to sudden death during sleep. Increased blood viscosity, arrhythmia, and interrupted breathing have all been proposed as causes, yet prevention often remains difficult. Traditional health cultivation emphasizes hot foot bathing: stimulating foot acupoints and using the meridians’ action can effectively prevent it.

Second, it relieves fatigue and promotes sleep. Hot water relaxes the channels, improves circulation, and removes heaviness in the lower limbs and fatigue throughout the body. It activates peripheral nerves, regulates the autonomic nervous and endocrine systems, benefits brain-cell proliferation, and gently stimulates the cerebral cortex, helping a person sleep peacefully. Thus hot foot bathing before bed surpasses tonics and sleeping pills.

Third, it brings the heart and kidneys into communication, harmonizes water and fire, and unites yin and yang, with pronounced effects in dispelling illness and strengthening health. “A tree ages first at its roots; a person ages first at the feet. To keep the legs and feet strong, bathe them in hot water every night.” Chinese medicine holds that more than 60 foot acupoints are intimately connected with the internal organs, each of which has corresponding points in the feet. Frequent hot foot bathing and massage of the soles and toes therefore have important therapeutic effects: opening the meridians, regulating the organs, promoting qi and blood circulation, increasing metabolism, and restoring yin–yang balance. They are therapeutic or supportive in neurasthenia, kidney deficiency, insomnia, headache, indigestion, colds, high blood pressure, and other conditions.

Many people, particularly young and middle-aged adults, either cannot sleep or dream constantly once asleep. This poor sleep quality substantially harms the body. In Chinese medicine, such insomnia commonly results from a lack of communication between heart and kidneys. Though apparently troublesome, it is readily treated by two measures: eat less dinner and sleep on as empty a stomach as possible, and bathe the feet in hot water before bed to reconnect heart and kidneys and harmonize water and fire. A child with a cold may also benefit from a hot foot bath before sleeping, because the many foot acupoints aid recovery.

Adjust the water until it feels somewhat hot to the hand. Support both of the child’s feet with one hand and use the other to apply water to them. Once accustomed to it, gradually immerse the feet and continue adding hot water. After about half an hour, the child begins to perspire. Dry the feet and immediately put the child under the bedcovers to sleep. Children are pure-yang beings with abundant qi and blood, however, so healthy children need not do this every night.

The water should be approaching boiling, with the temperature judged so that it does not burn the feet. Alternatively, begin with warm water and gradually add hot water until the feet are thoroughly warmed. Water should cover the ankles. Each bath should last at least 10 minutes, generally around 10 minutes, though longer is better; otherwise the effect is poor. Once the feet are hot, vigorously rubbing the soles and toes with both hands for 5 minutes improves the effect. Practiced nightly, this can treat illness and cultivate health. Many people merely wash or soak their feet in warm water before bed; this offers little health-cultivation benefit.

Remember: the practice is hot foot bathing before bed, not simply washing the feet.

My family has done this for years, even during the hottest days of summer, and greatly enjoys it. A few liters of hot boiled water each night make it simple, convenient, and inexpensive. Add more boiled water as needed to maintain the temperature. When the feet are slightly red and the whole body warm, sometimes lightly perspiring, dry them and go to bed for peaceful sleep. The benefits are indeed excellent. Ma Junren reportedly used the same hot-water foot washing when training his long-distance runners.

This comfortable, virtually cost-free method deserves wide promotion. Most people know hot foot washing before bed feels good, but few understand its many health-preserving and illness-dispelling effects. Having learned them here, put the practice into daily life and make it a habit. Middle-aged and older people should certainly do so. Some feel neither warmth nor perspiration afterward because they have excessive internal dampness or markedly deficient yang qi.

They may add mugwort leaves to the hot water and improve matters by using kidney-regulating methods to warm and replenish kidney yang in daily life.

Chinese folk sayings include: “To nourish a tree, protect its roots; to nourish a person, protect the feet”; “Frequent hot foot baths are better than frequent medicine”; “With money, take tonics; without it, bathe the feet often”; “Bathe the feet often and take less medicine”; “Eating a sheep every three days is less beneficial than a hot foot bath before bed”; “For a cold-induced cough without medicine, use boiling-water foot baths”; “For a cold, hot foot bathing is better than medicine”; “Bathe the feet nightly and cold will seldom rise from them”; and “In spring, hot foot baths raise yang and secure it against collapse; in summer, they dispel summer heat and dampness; in autumn, they moisten and nourish the lungs; in winter, they warm the dantian. Daily hot foot baths are better than tonics.”

8. Sleep at Hai and Rise at the End of Yin: Sleep Nourishes More Than Food — The Eighth Principle

Go to sleep at the beginning of hai, the 9–11 p.m. period — that is, at 9 p.m. — and rise at the end of yin, 3–5 a.m., or 5 a.m. The triple-burner meridian is strongest during hai and connects all the vessels. Sleeping then allows them to rest and recover, keeping a person free of major illness throughout life. During yin, 3–5 a.m., the lung meridian is strongest. Staying awake then weakens the lungs, encourages coughing, produces a bluish-gray complexion, and eventually predisposes one to lung disease. “The lungs receive the hundred vessels.” During chou, the liver renews the blood and supplies it to the lungs, which distribute it throughout the body during yin, preparing for the day’s activities.

Once yin has passed, therefore, get up and become active. Centenarians share a habit: sleeping at the beginning of hai, 9 p.m., and rising at the end of yin, 5 a.m. Few modern people manage this, which is why healthy, rosy faces are increasingly rare on the streets. Women wishing to preserve their appearance should sleep and rise early.

When nature stores, I store; when nature emerges, I emerge. When nature sleeps, I sleep; when nature wakes, I wake. This is a principle of cultivating health and preserving appearance. As darkness deepens, people should retire. The period from early hai to the end of yin and beginning of mao — 9 p.m.–5 a.m. Beijing time in the Beijing area — is especially active for new-cell division. During these 8 hours, each extra hour of rest produces more new cells; no amount of sleep after mao can compare. Thus 9 p.m.–5 a.m. is the golden period for sleep.

Within it, 11 p.m.–3 a.m. is the most precious time for yang qi to return to its root and renew itself.

In traditional culture, hai represents the renewed gestation of life, the beginning of a new cycle. Its zodiac animal is the pig. What image does a pig suggest? Laziness: after eating, it grunts and sleeps. At hai, likewise, sleep like a pig and enjoy it. Only then can new life be nurtured and the yang of zi emerge properly. Many traditional ideas reveal substantial knowledge when examined closely and deserve study.

The best rest begins a little after 9 p.m. Even if older people and children retire slightly later, they must do so before 10:30 p.m., and should sleep as soundly as a pig.

Traditional health cultivation regards sleep as the foremost tonic. Folk sayings include “Medicinal nourishment is inferior to food; food is inferior to sleep” and “A good night’s sleep restores a hundredfold vigor; a sleepless night leaves the whole body weary.” Why does sleep matter so much? As Laozi said, “One yin and one yang are called the Way.” Nighttime sleep restores and stores energy; daytime work and study release it. Yin and yang each account for half, and neither can be omitted.

Discussing sleep schedules requires considering the first health-cultivation principle of the Huangdi Neijing: “Follow the four seasons and adapt to cold and heat.” Health benefits only when we follow seasonal change and live harmoniously with changing time and circumstance. What characterizes each season? Spring brings birth, summer growth, autumn gathering, and winter storage. Nourish yang in spring and summer, yin in autumn and winter.

A day, like a year, has four seasons. A year contains twelve months and twenty-four solar terms; a day has 12 two-hour periods, or 24 hours. A day is a year in miniature, so daily rhythms should match its seasonal changes. From 9 p.m.–3 a.m. is the day’s winter; 3–9 a.m., its spring; 9 a.m.–3 p.m., its summer; and 3–9 p.m., its autumn.

Winter governs closure and storage, beginning at 9 p.m. Nature then sleeps. Remaining awake is like playing tug-of-war with heaven and earth. “Human strength cannot match heaven’s strength,” so nature inevitably wins. Only by matching bodily rhythms to natural ones can we “borrow heaven’s strength to restore human strength.”

Staying up too late takes two forms: being unable to sleep, and resisting sleep despite tiredness. In the first, yang qi fails to withdraw when it should; stimulating evening activities keep it outward, preventing yin from taking precedence. The second reflects mistaken priorities: forcing oneself to stay awake for mahjong, television, reading, or other activities, or working at night and sleeping late in the morning. Some claim their best work occurs between 11 p.m. and 1 a.m. In fact, they are spending the body’s most precious resource, exchanging life for work.

I sometimes advise friends in poor health to retire earlier, but most say they are too busy. Surely they are no busier than the American president. President George W. Bush went to bed at 9 p.m. every night, maintaining the habit even during the American attack on Iraq. Sleeping at hai and rising at yin therefore depends chiefly on holding the right view and giving it sufficient importance.

Habitually retiring too late damages gallbladder qi and, in serious cases, causes depression. The Huangdi Neijing says, “Qi strengthens the gallbladder” and “The eleven organs depend on the gallbladder.” The qi of all internal organs depends on the rising of gallbladder qi; when it rises properly, the body fares well. Zi, 11 p.m.–1 a.m., is the gallbladder meridian’s peak. Sleep stores and nourishes gallbladder qi, while wakefulness consumes it. Severe depletion produces “timidity disorder,” what modern medicine calls depression. In serious cases, sufferers regard their parents as strangers; further progression may lead to suicide or homicide.

Staying awake during zi, 11 p.m.–1 a.m., not only impairs bile metabolism but may cause anemia and insufficient blood supply. Liver deficiency fails to brighten the eyes above; blood deficiency fails to nourish the sinews below, causing tired eyes, mental weariness, and soreness and weakness of the lower back and knees. In the five phases, liver and gallbladder correspond to blue-green. Wakefulness during zi can make the face greenish, and during chou, dark blue-green. The lungs correspond to white; remaining awake during yin can produce a bluish-gray face. Because human cells are replaced about every 100 days, ancient health cultivators said, “Sleep comes first in nurturing life; one sleepless night cannot be made up in a hundred days.”

At 3 a.m. comes the day’s “Beginning of Spring.” Spring governs movement. Wind stirs the trees then, pumping nourishment toward their tips like a well pump; when warmth arrives after the spring equinox, buds emerge overnight. Humans and plants are both living things and respond similarly to nature. Nature wakes at 3, and bodily cells gradually awaken in response. This marks the beginning of yang qi’s outward rising, following its earlier growth, and the transition from stillness to movement. Deep sleep is needed to complete that process.

During yin, 3–5 a.m., the lung meridian is strongest and the lungs receive the hundred vessels. This is when people sleep most soundly. Skilled thieves therefore often act at three or four in the morning.

Why, then, do some people wake particularly easily during yin? Early waking reflects insufficient qi-and-blood energy and poor health. With abundant qi and blood, sleep during yin is necessarily sound and deep. People who go to bed early but wake early have insufficient qi and blood in the brain and too little yang to rise properly. This is commoner in older people and uncommon in the young. If an older person must wake every day then to urinate, it indicates kidney deficiency; the same applies to younger people.

By 5 a.m., dawn approaches and one should wake naturally, open the eyes, and rise. Remaining in bed when nature wakes is another tug-of-war that humanity cannot win. If one has not risen after 5, then at 6, the day’s spring equinox, the spirit cannot emerge, leaving inadequate energy. This explains modern “Sunday sickness.” With no work on Sunday, some sleep until 10 a.m. Yet 3 marks the beginning of spring, 6 the spring equinox, and 9 the beginning of summer. Failing to rise before summer means missing spring’s movement. Without movement there is no generation, and more sleep only creates more fatigue.

The Huangdi Neijing says, “Without spring there is no summer.” Summer is the great release of yang qi; without it, there is no vitality. Rise at around 5 a.m., or somewhat earlier in summer. If it is still dark, do housework, read, or write until daylight permits a walk outdoors. Both retiring too late and rising too late suppress yang qi, traditionally called “double killing.” Even after a late night, rise around 5 and make up sleep at midday.

On sleeping and waking times, a passage from the scholar Nan Huai-Chin is worth reading. He said that closing the eyes and truly sleeping for three minutes at precisely noon equals two hours of sleep. At night, five minutes at the exact midpoint of zi equals 6 hours. The timing of sleep is a profound subject, related to cosmic and earthly laws and the yin–yang principles of the Book of Changes. One can feel a force descending from beneath the heart and joining the force at the dantian, above the kidneys — the “completion of water and fire.” Suddenly, sleep is sufficient and vitality returns a hundredfold.

Those with insomnia or a genuine need to work through the night must therefore sleep at the exact midpoint of zi, even if only for 20 minutes, training themselves to do so if necessary. Remaining unwilling to sleep after that point is very bad. Worse still is staying awake during zi, then becoming drowsy at four or five near dawn, or at five or six during mao. Sleeping then leaves the whole day clouded. Those planning nighttime work should set aside even the most pressing matters at the midpoint of zi and sleep for half an hour.

But if sleepy during mao, 5–7 a.m., do not sleep — the meaning is to rise at 5 — and there will be enough energy for the day. Many insomniacs now remain tossing and turning after midnight, only falling asleep near dawn. Failing to sleep when one should, and sleeping when one should not, inevitably leaves the following afternoon muddled.

During the three winter months, however, one may sleep later into the morning. The Huangdi Neijing says: “The three months of winter are called closing and storing. Water freezes and the earth cracks. Do not disturb yang. Retire early and rise late, waiting for daylight. Keep the will concealed and hidden, as though harboring a private intention or having already gained something. Avoid cold and seek warmth; do not let the skin release its qi and rapidly deplete it. This is responding to winter qi, the way of nourishing storage.” Winter living should follow “early to bed, late to rise, awaiting daylight.” I oppose sleeping in and have never made a habit of it, but winter is an exception: sleep earlier, rise later, and wait for sunshine before getting up and going out. This is the teaching of the Huangdi Neijing.

Instead of daylight-saving time, therefore, we should adopt a four-season schedule based on the Great Treatise on Regulating the Spirit in Accordance with the Four Seasons in the Huangdi Neijing. That would truly accord with nature and regulate the spirit through the four seasonal qi. I believe winter’s “early to bed, late to rise” and “await daylight” would be welcomed. Who does not want to rise later in winter? Perhaps this will inspire an appreciation of the classic and Chinese health cultivation. Why should winter mean earlier sleep and later waking?

To accord with nourishing storage. Sleep itself is an excellent state of storage; because winter emphasizes this, its duration should naturally increase. Winter’s short days and long nights reflect storage, and people must respond by retiring early and rising late. How is the correspondence between humanity and nature put into practice? By nurturing storage in winter and following “early to bed, late to rise, awaiting daylight.”

Timing is essential. Store when nature stores, and release when nature releases. In practical terms, sleep is storage and work is release. Habitually working at night and sleeping by day fails to correspond with nature and reverses yin and yang, certainly harming the body. The young may not feel it, but will as they age. Those studying health cultivation should avoid this inversion. During winter, do not go out casually; exercise outdoors only when the sun is out.

A bedroom should not be too large, primarily to gather yang qi. Traditional health cultivation stresses closing doors and windows during sleep so that air can pass through without forming a current. During sleep, a protective layer of yang qi, called defensive qi, forms on the body’s surface. Moving air disperses it, prompting replacement from within. Repeated dispersal and replacement drain yang qi, leaving the whole body weak in the morning.

Avoiding noticeable air currents during sleep is a health-cultivation principle. Ancient wood, brick, and tile buildings allowed air exchange even with doors and windows shut; modern reinforced-concrete homes are much more sealed. Open a window while sleeping but draw the curtain to block drafts, keeping the air fresh without a current. When using air conditioning, do not worry about the extra electricity: leave a window slightly open for natural air, or open it fully behind a thicker curtain.

Chapter Sixteen of the Laozi says: “The myriad things flourish, and each returns to its root. Returning to the root is called stillness; stillness is called returning to life. Returning to life is constancy; knowing constancy is illumination. Not knowing constancy, reckless action brings disaster.” Returning to the root is therefore vital. For humanity, what does it mean to return to the root or renew life? Returning to the root is stillness. During a 24-hour day, when are we still? During sleep. Sleep is thus a return to the root, a stillness through which life is renewed. Each day offers such an opportunity.

Otherwise, how could life continue? Everyone should make good use of this opportunity for renewal.

In the body, “An abundance of yang is no cause for concern; what matters is its concealment and storage.” Sleep is the process by which yang qi is gathered, stored, and nourished. Although it does not directly supply nourishment as food does, it is more important than eating.

Sleep renews life by restoring vitality. Without that renewal, life is difficult to sustain. This is why insufficient sleep shortens life — a view shared by Chinese and modern medicine.

In sleep, yang qi is stored, entering the yin aspect and returning to its root. Sleep therefore both nourishes yin and brings yang back to the root: nourishing yin and subduing yang. Improving sleep improves the quality of that return, and a good return brings good renewal. Better sleep thus improves both quality and length of life. The Huangdi Neijing says, “With yang qi, stillness stores the spirit; agitation causes its dissolution.” Renewal is therefore also the storing of spirit.

When the spirit is stored, the ruler is clear; when the ruler is clear, those below are at peace. Cultivating life in this way brings longevity.

This brings today’s schoolchildren to mind. Under the current examination-driven system, hardly any child can retire early, starting in primary school and certainly continuing through high school. Sometimes homework remains unfinished even at midnight, requiring more late-night work. Students’ physical condition is therefore deeply worrying. Consider education in the West. Why do many people want to go abroad? Some do so for their children, feeling sorry for them and wishing to escape this situation.

Whether our country’s educational study schedules are scientifically sound deserves discussion. Health surveys from primary through secondary school show an unencouraging picture of children’s constitutions. This is a fact before us.

Let me close with a true story.

A pediatrician with considerable insight into Chinese medicine began allowing his son to arrive late at school each winter from primary school onward. Initially, he wrote absence notes, an easy matter for a pediatrician. Children are pure-yang beings and need no special exercise if their yang is properly protected; they will grow strong. Adequate sleep is therefore most important for their health. The doctor continued this winter practice, later explaining its significance to the class teacher after establishing a good relationship, so that notes were no longer needed.

The only thing he supervised daily was when his son went to bed and got up; he left everything else alone. The boy’s primary-school grades were naturally poor, but things changed completely in junior secondary school, especially in the second year. Without special exercise, he ranked first or second in the class at sports, excelling in high jump, running, and everything else. What does this show? A strong constitution. Six full years of sufficient sleep meant six years of carefully protected yang qi — how could he fail to thrive?

His academic results gradually improved too, eventually placing him first or second in class. Although only an individual case, it illustrates the point well and deserves serious reflection.

9. Moderate Sexual Activity to Nourish Essence and Qi for Longevity: The Ninth Principle

For someone with normal sexual function, intercourse about once a month is sufficient. Animal mating is seasonal, whereas human intercourse can occur at will. Excessively frequent intercourse consumes substantial physical energy and consequently increases illness. Marital intimacy should be restrained, following the principle that full essence overflows naturally: wait until the urge can no longer be contained rather than forcing ejaculation. About once a month is generally enough, though age and individual circumstances naturally allow variation.

Improved material conditions have increased overall vitality, with accompanying changes in sexual function. Because sexuality expresses vigorous life energy, people have made it a pleasure rather than solely a means of reproduction, thereby consuming great quantities of that energy. Human essence carries all of a person’s information and considerable energy; it is the material basis of procreation. By avoiding excessive loss and using essence to nourish ourselves, we can revive life from aging and renew it.

Many do not understand this simple law of life’s activity and consequently treat sex lightly. Excessive sexual activity depletes yang qi, exhausts essence and qi, and leaves a person beset by illness. This deserves attention: many people’s health has been damaged in precisely this way.

The most effective way for couples to reduce excessive frequency is to sleep under separate covers, preferably in separate beds. This improves hygiene and sleep quality and noticeably reduces sexual activity.

Sharing one cover makes intercourse too convenient. That is not necessarily good, because ordinary people’s self-control is limited. Laozi anticipated this when he advised, “Do not display what excites desire, so that people’s hearts remain undisturbed.” Desire, especially sexual desire, is difficult to govern. What arouses it is best kept out of sight or apart. As the ancients said, “Sleep alone to nourish essence and qi; abundant essence and qi bring longevity.”

Another saying reads, “The superior person sleeps in a separate bed; the middling person under a separate cover. A hundred doses of tonics are inferior to a month of sleeping alone.” People in poor health are advised to sleep alone and recuperate quietly for a time. This ninth principle puts into practice the Huangdi Neijing teaching of preserving and replenishing kidney qi. Ancient health cultivators opposed abstinence, but opposed indulgence still more. Moderation in sexual life accords with the art of health cultivation.

If the ancients valued preserving essence and avoiding sensual excess, why recommend intercourse about once a month for those with normal sexual function? Because, for an ordinary healthy person, that frequency stimulates vitality and brings benefit without harm. An important principle is first to feel happy: find a way to lift the spirits, since intercourse while unhappy is extremely unfavorable to health. The best time is 9–11 p.m., though this is not the best time for conception. After 11 p.m., it is inappropriate.

Why? Reading the entire book will make this clear.

Understand, too, that psychological stability and freedom from constant thoughts of sexual misconduct are signs of health and abundant essence and qi. A mind filled with such thoughts indicates deficiency and physical weakness. When already weak, intercourse only creates further weakness. Remember that constantly feeling sexually overexcited and wanting intercourse is an illness, usually excessive yang. Unfortunately, many are unaware they are ill and pride themselves on supposedly superior sexual function. This is rather absurd.

For further discussion, see Chapter Six, “Sexual Relations and Health Cultivation.”

10. Keep the Intestines Clear to Live Long: The Tenth Principle

The intestines may be cleansed once a month. A folk saying holds that “What enters but does not leave becomes poison.” Food that is neither absorbed nor eliminated can become toxins harmful to the body. Hence the ancient saying: “To live long, keep the intestines clear. Cleanse them at the full moon, purging impurity and removing toxins.”

Cleansing primarily removes stool from the colon, the body’s waste bin. Daily bowel movements do not remove it completely. The colon’s pouchlike structure, resembling a string of candied hawthorn berries, prevents stool from passing freely and also allows it to adhere to the intestinal wall, causing autointoxication and impaired venous return. Healthy people should therefore choose one day each month for cleansing. At that time, 5–20 grams of senna leaves may be steeped in boiling water and drunk.

I know there were once better secret cleansing formulas, but they may now be lost.

Chinese and Western medicine agree that the colon contains unclean matter and regard periodic purging as an important means of removing it. A day of diarrhea each month to clear the colon and prevent autointoxication is very necessary. More importantly, stool lodged in the colonic pouches is difficult to remove through normal bowel movements and eventually hardens into fecal stones. This may be the real reason for monthly cleansing. Some dismiss it as needlessly giving oneself diarrhea with nothing better to do.

Afterward, however, one experiences a delightful feeling of lightness throughout the body.

Stool is harmful and must be eliminated promptly and completely. Can its quantity be reduced? Yes. Taking more meat broth, soy milk, and fruit juice for nourishment while eating fewer pieces of meat reduces stool formation. Stay home on the cleansing day and wash the anus after each episode of diarrhea.

Remember: people who are physically weak or qi-deficient must not use this cleansing method indiscriminately. The senna method is as follows:

① On the cleansing day, do not eat ordinary meals. Take only meat broth, soy milk, and fruit juice, and rise early.

② Steep 5–20 grams of senna leaves in 500 milliliters of boiling water. Let the infusion cool until warm, then drink it all at once. Steep the same leaves again in another 500 milliliters of boiling water, allow it to cool until warm, and drink the second infusion all at once.

③ After about four hours, the first evacuation begins, passing relatively hard stool.

④ Another loose bowel movement follows.

⑤ Finally, yellow watery stool appears. This yellow diarrhea is the goal of cleansing; only by reaching it can the colon, gallbladder, pancreas, and liver truly be cleaned.

⑥ After each episode, wash the anus and drink cooled boiled water.

⑦ First-time users may pass scattered, extremely hard fecal stones.

⑧ Those who cleanse monthly will not pass stones but will pass very sticky stool.

⑨ During cleansing, go promptly to the toilet at the first abdominal pain rather than waiting for urgency, to avoid soiling your clothes.

Looking around, we find people with frequent constipation, bad breath, or large bellies whose colons contain substantial waste. Carrying it while walking, working, and enjoying themselves is exhausting. Yet they do not know to clean the colon. They know only how to take food in, not that some becomes waste which, without prompt and complete removal, turns into dirty fecal stones.

They wash their faces, hands, and bodies but do not know to remove these internal stones. This is profound ignorance.

Some people have no bowel movement for a week after cleansing. Colon-cleansing clinics in Europe, the United States, Russia, and elsewhere call this secondary constipation and classify it as a side effect. In fact, it is not constipation: the colon has emptied, and stool cannot form for several days. Once it forms, however, prolonged retention can dry and harden it. What can be done? Take 50 grams of raw sesame paste in the days following cleansing.

How should it be prepared? Formerly a rolling pin was used; today a grinder can turn raw sesame into paste, which is eaten uncooked. Do not substitute sesame oil or roasted sesame.

There is also a weekly method. Those who do not cleanse monthly are advised to try weekly cleansing; without abdominal bloating, set aside one day every seven days. The Book of Changes says, “Returning along its course, it comes back in seven days.” Seven therefore represents a recurring cycle. Among the eight trigrams, seven also belongs to Gen, meaning stopping, indicating that a process has completed its cycle. Ancient Chinese physicians consequently often used seven in prescriptions, such as seven doses of a decoction. The seven-day week thus did not originate solely in the West; its cycle already appeared in the Book of Changes.

Every seven days, therefore, devote one day to small amounts of easily digested vegetarian food, with plenty of water or juice. Although less thorough than the preceding method, it can clear gastrointestinal residue, cleanse the blood vessels, and produce a noticeable sense of bodily lightness.

“To live long, keep the intestines clear” has another meaning: stool within the intestines should be as clean as possible. This is fundamental to longevity. Which stool is relatively clean and less harmful? That produced by vegetarian food. Such food not only avoids foul-smelling stool but has the therapeutic effect of binding intestinal toxins. Because coarse grains produce more stool, they should form the staple. They do not provide enough nourishment alone, however, so include vegetables, meat broth, juice, and soy milk.

These are the ten principles of health cultivation. They can bring distinctive changes in people’s health. Some fear the lifestyle is monotonous; in fact, it can be relaxed and joyful.

By Their Eating Patterns, People Fall Broadly into Four Groups

First: Those Who Eat Only Cooked Meat

Vitamin deficiency shortens the lives of this group. For example, the average lifespan of Eskimo people is only 37 years. Before modern civilization reached their homelands, however, they ate fish raw and lived much longer, because raw fish made vitamin deficiency less likely. Vitamins in raw meat disappear when subjected to high heat.

Naturally, people who eat exclusively cooked meat are exceedingly rare.

Second: Vegetarians

This group is weakened by insufficient animal protein; examples include Buddhist monks, nuns, and lay practitioners. Most follow vegetarian diets from religious conviction, a commitment deserving admiration. Vegetarianism itself, however, does not accord with health cultivation. Protein malnutrition often causes illness among vegetarians and occasionally even costs a life.

Those with abundant essence and qi can, of course, eat vegetarian food or even forgo food. The ancients said, “With sufficient essence, one does not think of desire; with sufficient qi, one does not think of food; with sufficient spirit, one does not think of sleep.” Certain traditional mind-and-body practices can indeed gradually replenish essence and qi and purify the body. After practicing them for a time, qi and blood become abundant and the ability to transform food grows strong. Light vegetarian food can then fully meet the body’s needs, while rich flavors such as meat become a burden.

At that point, vegetarian eating is necessary. When I met a teacher I know this year, she had not eaten in the ordinary way for more than half a year. She drank some water and, at most, ate a piece of fruit every few days. Sleeping only around an hour daily, she remained mentally and physically vigorous. The human body exhibits many unusual phenomena of life, which we can reveal and discuss individually on a future occasion.

Most vegetarians today do not know how to use these special traditional practices to replenish and strengthen essence and qi. Simply persisting with vegetarian food therefore readily produces malnutrition. I advise religious vegetarians to deliberately eat more beans for plant protein; lacking both animal and plant protein creates serious difficulties for health. Limit tofu and similar soy products, which damage stomach qi, and minimize or avoid vegetable oils subjected to high temperatures, which alter them. Small amounts of raw cold-pressed olive oil, camellia oil, or similar oils may be added — a few drops after vegetables leave the pan.

Some vegetarian monks develop large bellies, high blood lipids, and high blood pressure because they consume too much vegetable oil altered by high heat.

Third: Those Who Eat Both Meat and Plant Foods

They consume large quantities of solid animal protein, high-calorie refined grains, and animal and vegetable fats.

This is the most common group. Excess calorie intake makes them prone to many illnesses, particularly heat-type conditions such as high blood pressure, high blood glucose, and high blood lipids after fifty. Most people around us fit this pattern.

Fourth: Those Whose Staples Are Coarse Grains and Vegetables

Apart from liquid animal protein, they consume essentially no solid animal protein or high-calorie animal and vegetable fats.

Balanced nutrition makes them less susceptible to disease. A very small number of people attentive to health cultivation exemplify this group.

Which of these four groups would you consider best? Naturally, the fourth. Practicing the ten principles can produce this kind of healthy population; ordinary people can also develop strong resistance to illness through this approach.

After a month of following the principles, most people report a better complexion, fairer and more lustrous skin throughout the body, greater strength, cleaner blood, higher hemoglobin and albumin on blood tests, and normal blood viscosity. Blood indicators best represent overall health. Their only difficulty is uncomfortable hunger each evening. What should they do? If very hungry, take easily digested liquids such as meat broth, soy milk, congee, or fruit juice.

People following this approach are indeed less likely to become ill.

The ten principles are both a preventive method for the healthy and a basic treatment for those who have become ill without practicing health cultivation. As stated in the introduction, every way of living has pharmacological effects, not merely medicines. Patients who continue seriously unhealthy habits create illness while receiving treatment and are extremely difficult to restore to health.

Many diseases arise from eating and inactivity. The ten principles emphasize avoiding indiscriminate eating, anger, and idleness. Food should be nutritious and readily absorbed; harmful substances should be kept out, while internal toxins are expelled. They emphasize remaining “thirty percent cool and seventy percent full.” The former means not only avoiding excessive clothing but also keeping covered in spring and accepting some coolness in autumn, as well as eating coarse grains and avoiding excessive calories.

Anyone wishing to live to a hundred must therefore attend to health cultivation. This explains the longevity of traditional Chinese physicians. Yet Chinese people’s appetite for food leaves the present picture unencouraging. Many have liver damage, diabetes, coronary heart disease, high blood lipids, or high blood pressure. In today’s peaceful era, disease is shortening human lives because so many do not understand health cultivation.

Widespread Adoption of the Ten Principles Raises Two “Side Effects”

First, if people generally live longer after adopting them, will families and the nation bear an excessive burden?

No. An aging society may seem alarming: people assume that too many older adults unable to work will overburden the young. But few consider that many older adults still able to work would reduce that burden. An aging society is therefore not inherently frightening; the key is older people’s health.

Second, if people stop eating many foods after adopting the principles, will the market decline?

No. Demand for rice, wheat, and sticky rice would fall, but demand for meat, vegetables, fruit, and coarse staples such as corn, soybeans, and sweet potatoes would rise. Restaurants would be affected because fewer people would eat dinner as they do now. New restaurants would emerge, however. When dining out in the future, we would order meat broths first rather than cold dishes. Congee restaurants, in particular, would grow popular, and some could become well-known brands.