The main ingredient of cold drinks is water. Besides, ice cream and ice cream contain some sugar and milk. These nutrients are low in content and cannot be used as staple food to provide nutrition. If a large number of cold drinks enter the digestive tract, supercooling will seriously affect the secretion of digestive juice and gastrointestinal function. Normal digestive juice contains gastric acid and digestive enzymes, which helps to kill bacteria entering the digestive tract and promote food digestion and absorption. If the digestive juice is reduced, the digestion and absorption of food will be affected, which will easily lead to intestinal infection, loss of appetite, abdominal pain, diarrhea and fever. It is not advisable to eat cold drinks before or after meals. Eating cold drinks before meals will affect appetite and lead to nutritional deficiency. Cold drinks contain nutrients such as milk, but the content is far less than normal diet. Eating cold drinks immediately after meals will reduce gastric acid secretion, reduce the immune function of digestive system, lead to bacterial reproduction, and cause intestinal diseases such as enteritis. Moderate cold drinks can cause gastric mucosal vasoconstriction, reduce gastric juice secretion, lead to decreased appetite, and affect human digestion of food. The intake of a cold drink should be around 150ml. It's very hot in summer, so it's a good enjoyment to drink a can of frozen coke and bite off some popsicles in one breath. However, the damage to the body can not be made up by this refreshing. Drinking cold drinks is the same as drinking hot soup, savoring it carefully and drinking it slowly. It is advisable to avoid different groups of people and have different requirements for cold drinks, especially those with diseases, and should eat less or even avoid cold drinks. Babies avoid cold drinks, and children eat less cold drinks; People who are old and weak and suffer from cardiovascular diseases should not eat more cold drinks. Be careful to eat cold drinks from roadside stalls. When buying, carefully check the production date and shelf life, and try to choose products with close factory date. Carbonated drinks are rich in taste. According to the classification standard of soft drinks in China, there are quite a few flavors of carbonated drinks: fruit juice, cola, low-calorie and other types of carbonated drinks. Professor Zhang Jiazhi said that the original juice, such as orange juice soda, orange juice soda and so on, and a lot of vitamins and other nutrients were added to the fruit juice carbonated drinks. However, compared with it, fruity carbonated drinks are made of essence, such as orange soda and lemonade. Although the color is bright, it only imitates the taste of fruit, not the taste of fresh fruit, so the nutritional value is much inferior. Coke carbonated drinks are quite special. It is a mixture of various fruit flavors, very refreshing and unique in taste. There are also some low-calorie carbonated drinks with low sugar content, but you can drink more appropriately.