It is to study the performance of food and nursed back to health according to the performance of food. Eating is the expression of life activities, and it is the guarantee of health and longevity. "The valley is prosperous, and the valley is dangerous."

Only when you have enough food can you be happy. "The foundation of the people is food." Diet not only maintains individual life, but also relates to the continuation of race, national prosperity, social prosperity and human civilization. The first drug monograph in China, Shen Nong Ben Cao Jing, which appeared in the Han Dynasty, contains 365 kinds of drugs, among which many foods, such as jujube, lotus root, yam, Euryale euryales, honey, coix seed and so on, are listed as top-grade drugs with health care and longevity.