Vegetarians Should Supplement Vitamin B12; Intermittent Fasting or Gradually Cutting Food Benefits the Body

Overweight people are more prone to heart disease, cancer, and diabetes; about 2.3 billion people worldwide are now overweight. The main reason humans are getting fatter is that the structure of the human diet has undergone an irreversible change.

In the food chain, the higher an organism's trophic level, the more toxic substances accumulate in its body. Because toxic substances cannot be broken down or excreted within an organism, they accumulate level by level as they pass up the food chain. Humans sit at the very top of the food chain, so among all living things, humans carry the greatest accumulation of toxic substances. In recent years, viruses from many wild animals have also been transmitted to humans, precisely because human gourmands are so careless of their own health.

As the proportion of animal-sourced food in the modern diet grows, diseases linked to these foods are also growing. Cancer, diabetes, and cardiovascular and cerebrovascular disease are all related to the human diet. In recent years, the World Health Organization has repeatedly called on people to change their diet and greatly reduce the proportion of animal-sourced food in it.

Regrettably, as life grows more affluent, people are growing fonder of animal-sourced foods—various meats, eggs, fish, and dairy products. The American Institute for Cancer Research advocates that animal-sourced foods should not exceed 20% of the human diet, and that a vegetarian diet is healthier for people.

But an absolute vegetarian diet easily brings other health problems: vegetarians have a greater risk of pernicious anemia and stroke than meat-eaters, because vegetarians lack vitamin B12. Thus long-term strict vegetarians should supplement vitamin B12.

Vitamin B12, also called cobalamin, is the only vitamin that contains a metal element. Its main physiological role in the body is participating in the manufacture of red blood cells in the bone marrow; a deficiency of vitamin B12 leads to anemia. Vitamin B12 in nature is all synthesized by microorganisms; higher plants and animals cannot make it. Vitamin B12 is the only vitamin that requires an intestinal secretion (the intrinsic factor) to be absorbed. Some people, because of gastrointestinal abnormalities, lack this intrinsic factor, and so even with an ample dietary supply of vitamin B12 they still develop pernicious anemia.

Plant foods contain essentially no vitamin B12, which is why many strict vegetarians look sallow; they should supplement vitamin B12. Vitamin B12 can also protect brain nerves from damage. The best way to supplement vitamin B12 is to eat meat in moderation. But some people, for religious or other reasons, are unwilling to eat meat; such people should consider taking oral vitamin B12 to avoid pernicious anemia and nerve damage.

Moreover, food contamination is also a major problem. As environmental pollution grows worse, there is no safe food left on Earth; so-called organic food is not safe either.

Current middle-school biology textbooks describe this: from the 1950s to the 1970s, people often used a pesticide called DDT to kill agricultural and forestry pests, but DDT was never used in the uninhabited Antarctic. From the 1970s on, researchers found DDT in the bodies of fish, shrimp, and penguins in Antarctic waters. This shows that the biosphere of our planet is a tightly linked whole, and no one can escape environmental pollution.

Another very common modern phenomenon is eating too much. With ample food supplies, many people are not just full but stuffed. Especially during festivals, with banquet after banquet, it is easy to overeat. People put on three jin every holiday and have turned festivals into a burden.

Intermittent fasting benefits health, but it must be done properly. Some institutions that run "bigu" fasting regimens have over-commercialized intermittent fasting, and their views are overly extreme, so that some patients who were already weak developed serious problems during the fasting process.

Generally speaking, fasting one day a week helps the body greatly (on a fasting day, if hunger becomes unbearable, fruit and vegetables may replace a meal). For overweight people in particular, moderate fasting further helps raise their own immunity.

Some obese patients I know eat a huge amount every day, yet I have told them to start by fasting one day a week. Many patients object: "I'm already so hungry, you still make me fast!" But actually, this is precisely because they have eaten too much that they are hungry. Their spleen and stomach are weakened by the heavy diet, and the stomach is enlarged by long-term overeating. So I always tell such patients that the way to start losing weight is not to eat less in one sudden drop, but to fast intermittently and gradually reduce the food amount.

Long-term overeating enlarges the stomach, so the more one eats, the hungrier one gets. By fasting one day a week, we can shrink the stomach bit by bit, and also give the spleen and stomach a rest, letting the body's digestive system recover its function. At the same time, the body can also consume its own excess fat, which is a great benefit to health.

TCM holds that the spleen governs the flesh and muscles, and is the acquired foundation, the source of qi and blood production. The function of the spleen is greatest at midday, and weakens after noon, so among the three meals of the day, a good breakfast and lunch should be eaten, and a light, simple dinner. Modern people eat their biggest meal in the evening and like late-night snacks; such people tend to accumulate phlegm-dampness in the body and are prone to obesity.

So we should indeed move our main eating time forward, eat well at noon, and eat little in the evening; we should avoid overeating and long-term gluttony, which raise our blood lipids and blood sugar and burden the heart and brain.

In short, we must keep moderation in eating and drinking, avoid a glut of fish and meat, and avoid eating until we are stuffed. Otherwise, after we have eaten our fill, the burden on the body is very heavy.

Besides intermittent fasting, another approach is to reduce food gradually. Step-by-step reduction of one's rice intake is a feasible way to diet and lose weight. For example, first cut the amount by 10–20%, adapt to it for a while, then cut another 10–20%. This way of reducing food does not bring serious discomfort and helps weight-loss succeed.

Of course, less food is not always better. A person should decide how much to eat according to daily activity level; only when the calories burned and the calories taken in are roughly balanced does the body stay in its best state.

For the great majority of modern people—especially urban Chinese—nutrition is basically in surplus. Most people eat more than their bodies need, taking in too many calories and burning too few, so obesity keeps rising among city dwellers. These obese people face a far higher risk of heart disease, hyperlipidemia, diabetes, and cancer than those of normal build.

These are what we call the "diseases of affluence." The spectrum of human disease keeps changing with the times. After World War II, human society entered a nearly century-long period of peace and development; the world economy prospered as never before, food grew ever more abundant, and sanitation improved greatly, so the death rate from infectious diseases fell sharply, and the "diseases of affluence" became humanity's greatest health enemy.

And these diseases of affluence carry a heavy medical burden; the medical resources many of their patients consume cannot be bought back with all the wealth they earn in a lifetime.

I have long advocated eating mostly vegetarian, and urge everyone to fast intermittently or gradually cut their food to lighten the burden excess calories place on the body. Yet even within my own family this advocacy achieves little. In the battles at the dinner table, I, a man of medicine, always lose to my food-loving relatives; I can only keep myself right.

I can only hope that patients troubled by disease will learn from their pain and change their diet and eating habits. What you lack is not nutrition, but healthy eating habits.

Recovery from illness requires combining medical treatment with self-care; the doctor's treatment plays a limited role, while the patient's own nurturing matters more.

Many diseases need no treatment at all; adjusting diet and exercise habits can reverse them on their own. For example, many patients with polyps or fatty liver, and even some with type-2 diabetes, can completely reverse their condition by dieting, exercising, and losing weight.

There is no need to blame doctors for poor skill or the medical burden for being heavy; many people ruin their own bodies, and as the saying goes, it is their own fault. Some patients, even though they know they need a healthier lifestyle, still cannot discipline themselves or control their appetite. Such patients really are not worth pity. After all, when a person stubbornly insists on charging toward the gates of hell, no one can pull them back.