Nutrition is the function that human beings absorb nutrients from the outside to maintain life activities such as growth and development, and it is also the process that human beings obtain and use the materials and energy necessary for life activities. Therefore, nutrition represents an "action", "behavior" or "biological process". "Nutrition" is not synonymous with food or nutrients. The understanding of the word nutrition in society is not correct enough, and the words are not appropriate, such as "rich nutrition", "rich nutrition" and "with or without nutrition". The correct word is "nutritious" or "nutritious".
A person's nutritional status refers to the physical condition related to nutrition, that is, the health status of food ingredients and the utilization status of nutritional ingredients. In its development process, nutrition not only includes the changes of food entering the body, such as participating in biochemical reactions and combining with tissues and cells; It also includes instructing people how to choose food to ensure the normal growth, development and reproduction of the body. Therefore, nutrition has not only biological significance, but also social and economic significance.
Five nutrients of nutrition:
1, protein: Human cells are made of protein. The function of protein in human body is to maintain and repair the tissue and muscle structure of the body, and it is also a component of immune system antibodies, which plays an important role in metabolism.
2. Sugar: Carbohydrate is the main energy source of human body, which generates four calories per gram to supply the main energy source of cells, nervous system and brain. Disaccharides are mainly stored in starch in cereals and wheat products, while monosaccharides are stored in natural fruits.
3, fat: fat can produce nine calories per gram, which has the function of supporting and separating the main organs of the body.
4. Minerals: act as catalysts for various chemical reactions in the human body. The main minerals are: calcium, magnesium, phosphorus, potassium and sodium. Trace minerals: copper, zinc, manganese, iodine, silicon and iron.
5. Vitamins: Vitamins are nutrients for the human body to maintain normal metabolism. When dieting, it is best to supplement a A to Z vitamins and minerals every day.
The above contents refer to Baidu Encyclopedia-Nutrition.