Water is one of the seven nutrients required by the organism, an important part of the diet and the source of all life. In general, for healthy adults living in mild climates with light physical activity need to drink 1400-1600ml of water (7-8 glasses of water) daily. In conditions of high temperature or strong physical work, it should be increased appropriately. Not drinking enough or too much water can be harmful to the organism. Drinking water should be active, do not feel thirsty when drinking water, a small amount of multiple times. The best choice of plain water, you can also choose appropriate light tea water. There is a wide variety of beverages on the market, and some dairy drinks and juice drinks contain a certain amount of nutrients, which can be appropriately supplemented, but it is not recommended to drink a large amount for a long time. Some beverages contain a certain amount of vitamins and minerals, which can be appropriately supplemented after sports or outdoor activities. However, many beverages contain a certain amount of sugar. Drinking a large amount of beverages with high sugar content will inadvertently overload the energy intake and cause excess energy. In addition, the sugar left in the mouth will produce acid under the action of bacteria, which is not conducive to dental health.