1. protein: It is the most important nutrient in human tissues and the main transporter of substances in the body. Function: supply energy. Regulate physiological functions. The main materials for maintaining human growth and development, forming and repairing cells and tissues. Milk and meat (eggs, fish and beans).

2. Sugar: it is the main source of heat energy in human daily life. Function: supply energy. Help the metabolism of lipids in the body. Form substances in the human body and regulate physiological functions.

3. Lipid: the so-called oil, like sugar, is one of the main sources of human heat energy. We divide lipids into two categories: animal lipids and plant lipids. Generally speaking, vegetable lipids are good for human body. Function: supply heat energy. Form subcutaneous fat and keep body temperature constant. Assist the absorption and utilization of fat-soluble vitamins. Protect internal organs.

4. Minerals: It contains many kinds of substances, and the most important ones are, for example, calcium, which is an element that constitutes bones and teeth and is also the main substance that regulates heartbeat and muscle contraction; Phosphorus: it is also one of the main substances that constitute bones and teeth; Iron: It is one of the main components of heme, and it is also a component of some enzymes in the body. In addition, there are many other minerals, which have an important impact on the physiological function of the body, and none of them can be neglected. Function: the main raw material of organic matter that constitutes body cells. Regulate physiological functions.

5. Vitamins: divided into two categories: water-soluble and fat-soluble. Function: Promote metabolism. Regulate physiological functions.

6. Water: It is the best lubricant and solvent in the body. There are many substances in the body that must be dissolved in water to react, so it is also one of the indispensable nutrients for the human body. Function: Promote the digestion and absorption of food. Regulate body temperature. Maintain normal circulation and excretion. Help maintain the balance of electrolytes in the body. Moisturize the surface of each tissue and reduce the friction between organs.