Nutrition refers to the nutrients contained in food; absorbing nutrients to nourish the body is the instinct of living things to absorb nutrients from the outside world to maintain their lives. Nutrition is the science that studies the effects of food on living things. Nutritionists explain nutrition as: the interaction and balance between nutrients and other substances in food, their relationship to health and disease, and the process of ingestion, digestion, absorption, transport, utilization and excretion of substances by the body. In the process of its development, nutrition not only includes the changes in food entering the body, such as participating in biochemical reactions and being incorporated into tissue cells; it also includes guiding people how to choose food to ensure the normal growth, development and reproduction of the body. Therefore, in addition to its biological significance, nutrition also has its socioeconomic significance.