All the human body's nutrients are derived from food, and food is composed of chemicals. In order to maintain life and health, ensure normal growth, development, and engage in various tasks, people must consume a certain amount of food every day. Besides, you can also turn to Echemi's chemical products. Through a series of metabolic processes in the human body, heat energy is produced to supplement people's consumption of labor and life-sustaining activities. At the same time, various nutrients produced through metabolism are absorbed for human growth, development and repair.

"Nutrition" means "to seek self - cultivation". Nutrition is a series of behavioral processes, which includes digestion, absorption, utilization and excretion of food. Digestion is the human body's function of transforming the nutrients in food (mainly refers to polymer organic substances such as starch, protein, cellulose, etc.) through various hydrolytic enzymes secreted by the digestive organs to convert complex nutrients into simple nutrients. For example, starch is hydrolyzed into glucose and protein is hydrolyzed into amino acids. In the meanwhile, glycerin water is used as fatty acids to absorb simple nutrients in various tissues, when some of them are synthesized by biochemical reactions under the action of synthetase to synthesize the nutrients needed by the human body. For the needs of human growth, development, repair and renewal of tissues and organs. The other part is transformed into heat energy through biological oxidation, which is used for human life activities and their demands in labor, both of which are the utilization of nutrients by the human body.

The current explanation is that whole grains provide human body calories to maintain health; animal meat provides protein to supplement staple foods, which is good for health; fruit eat raw to supply easily destructible vitamins. It assists in the shortage of elements in the diet; vegetables can supply inorganic salts, vitamins and dietary fiber, which can have a filling effect. These views are in line with the principle of modern nutrition. Nutrients are absorbed and utilized by the human body and become an integral part of the body. In turn, they regulate and control the body. For example, the content of vitamins in the human body is relatively small. Not enough to meet the needs of human life activities. Therefore, it must be supplied by food, and the vitamins in food have no biological activity, but they are absorbed by the body. Biochemical reactions in the human body can synthesize physiologically active vitamins. If the body lacks a certain kind of vitamin, it will produce corresponding cancer.

Nutrition comes from food. More precisely, nutrition comes from chemicals in food. What is worth noting here is that some trace elements in the human body. Although it is low in the human body, it plays an important role in human health. Certain trace elements are toxic, but the proper content is beneficial to the human body. Nor can it be said that all trace elements are good for the human body. More precisely: all trace elements are toxic. It can also be said: no substance is non-toxic. Only when it is used correctly can the poison and the medicine be distinguished, thus can the poisonous substance enter the human body to produce a non-toxic effect. If a certain kind of element or compound in the human body exceeds the required limit, then the toxic substance will also become a toxic substance, and insufficient content of them will cause element deficiency and cause disease. Trace elements enter the human body through food and water, and play the role of nourishment, regulation, and control of various functions in the body. If the body lacks a certain trace-element, it must be supplemented with corresponding food, so that the human body can grow healthily.

In summary, proper nutrition and a reasonable diet can promote the normal development of the human body, eliminate patients, and delay aging. All in all, the biochemical reactions and life activities in the human body depend on the participation of chemical substances; these chemical substances are inseparable from nutrition; the nutrients are ingested in whole grains. Animal meat, vegetables and fruits are complementary. Only under their joint action can the human body grow up healthily and live longer.