Under normal circumstances, people's gastrointestinal peristalsis has a strict time rhythm, while the secretion of digestive juice is relatively stable. Moderate diet creates favorable conditions for the normal digestion process. If you overeat, the normal physiological activities of the gastrointestinal tract will be affected, the burden of the gastrointestinal tract will be aggravated, the peristalsis of the gastrointestinal tract will be inhibited, and the delivery of food will be slowed down. The accumulation and fermentation of food in gastrointestinal tract will cause abdominal distension, abdominal pain, belching, hiccups and even vomiting. The most serious consequence of overeating is death due to acute gastric dilatation. It is well said in "Health Taboo": "Those who are good at health preservation should be hungry first, thirsty first if they are not full, and should not overeat. They should eat less and should not eat more." This method of "eating a little more meals" and eating seven or eight points is also used for patients with peptic ulcer and gastroenteritis, and of course it is also suitable for the elderly and people with poor spleen and stomach and poor digestive function.

On the other hand, if the diet is insufficient, it will not meet the needs of the human body to absorb nutrients. Over time, it will also cause diseases, such as gradual emaciation, malnutrition, nutritional deficiency, anemia and so on.