There are more than a dozen "no food" in the tenth article of The Analects of Confucius, which expresses his views on food health, food hygiene and food etiquette. From today's perspective, he can't help but admire his old man's understanding of China's national conditions, people's feelings and sense of body (the particularity of human body). For example, he said immediately after "there was no food (there was no food on the day he was born)"

"Don't eat from time to time" means "eat in season". Generally speaking, people should have a food list suitable for their growth, development and metabolism at different stages of their lives. In a word, they should arrange reasonable meals according to the four seasons of the year. In short, they should eat in time within a month or a day. In the final analysis, eating on time requires people to follow the rhythm of the internal biological clock.

In fact, as early as the Zhou Dynasty more than 2,000 years ago, there was a "Four Seasons Food List". The four seasons of food are completely different, because the meat quality of animals will be different at different growth stages. The so-called "Little Man River (mussels) is thin and soft, the crucian carp is empty from summer to day, and the crab is empty on the Dragon Boat Festival" is a kind of food that goes against the times. Like a seafood river, before Qingming, swordfish was soft. Carp and shrimp in summer; Autumn bass frost crab, because the fish and shrimp at this time, fat and delicious, nutritious.

Plant raw materials, people who eat its stems and leaves, should be based on its lowest lignin content. People who eat its roots and stems should choose the one with sufficient starch content and easy saccharification. People who eat its flowers should choose it when it is in bud. People who eat its fruit should not eat immature fruit. It should be noted that "May radish and spinach, June leek and old donkey grass" is not just an expression.