There are four reasons why carbonated drinks such as cola should not be drunk often: 1) carbonated drinks contain gas, that is, carbon dioxide will stimulate the secretion of gastric juice, and hyperacidity will easily lead to bloating, loss of appetite and reduction of daily food intake. Insufficient intake of nutrients in diet will affect normal growth and development, learning effect, sports performance, work performance and health. 2) Carbonated drinks contain sugar. A can of 355 c.c cola contains about 35 grams of sugar, equivalent to 140 calories, equivalent to half a bowl of rice. However, only the calories are equal, but the nutrients are quite different, because sugar has only calories and no other nutrients at all. It is empty card food or junk food with calories. If you drink regularly, every little makes a mickle, you will gain weight and easily develop a bad eating habit of being sweet. You only like sweet water, not boiled water. In addition, sugar has a bad effect on dental health. 3) Phosphoric acid, another component of carbonated drinks, will reduce the absorption of calcium in the body and affect the normal development of bone growth and height. Children and adolescents in growth and development need enough calcium to make bones grow and develop normally, maintain good bone metabolism and achieve the best bone density, so it is even more inappropriate to drink carbonated drinks. In addition, phosphoric acid will hinder the absorption of iron, which is one of the main substances for making blood. Once iron is not enough, it will cause iron deficiency anemia. Children who are growing fast need enough iron to make blood quickly. Especially adolescent girls, the demand for iron is higher, because a lot of iron is lost every month during menstruation. Therefore, girls who love carbonated drinks are more prone to iron deficiency anemia. 4) Caffeine contained in various colas will stimulate myocardial contraction and accelerate heartbeat and breathing; It will stimulate gastric acid secretion and harm the stomach; It has diuretic effect, and the elderly are prone to dehydration; Long-term drinking will be addictive. Once you don't drink it, you will feel uncomfortable, listless or have a headache. If you drink too much for a long time, that is, caffeine exceeds 200 mg every day, there will be chronic poisoning phenomena such as indigestion, headache, insomnia, nervousness, trembling, irritability and rapid heartbeat. Caffeine is found in cola, tea and coffee. A can of 355 c.c cola contains 65 mg of caffeine, a can of 350 c.c oolong tea contains 80 ~ 120 mg, and a cup of instant coffee contains 85 ~ 200 mg. Therefore, if you drink more than three cans of coke a day, or drink a can of coke, plus a can of oolong tea and a cup of coffee, you will consume more than 200 mg of caffeine, which will easily lead to chronic poisoning if you drink it for a long time. I hope this answer can help you.