The content of caffeine in drinks should be limited to 2%.

At the end of the 19th century, coffee sales in the United States increased greatly. John Pemberton, a pharmacist in Atlanta, Georgia, has made an innovation. He used coffee as a basic ingredient to make a cold drink that relieves fatigue, creating a competitor to coffee, Coca-Cola, which contains caffeine and is made from syrup extracted from two Latin American plants. Pemberton made the Coca-Cola recipe out of a three-legged brass can in his backyard. The name comes from Pemberton's accountant Frank Robinson,Robinson, who loves calligraphy. He wrote "Coca Cola" in a special way, like a flowing letter, and later became a world-famous trademark. The soft drink was first sold at the Jacob drugstore in Atlanta on May 8, 1886. He sells about 9 tins a day, selling $50 in the first year, less than his $70 investment. Coca-Cola's first-year sales were not as profitable as they are now. Later, other smart Americans invented hamburgers instead of steaks and replaced natural fruit juices with all kinds of soft drinks. 、

Before 1903, the soft drink was sold on the market as a tonic with ingredients including cocaine and caffeine-rich Coke tree nut extract. Later, FDA banned the sale of drinks containing cocaine and limited the amount of caffeine in drinks to 2 per cent. Nowadays, this synthetic carbonated drink, which can relieve fatigue, is very popular. The basic ingredients in its regular formula include sugar and caffeine, while Diet Coke's formula does not contain sugar. Large bottles of 600 to 2-liter drinks contain 120-400 milligrams of caffeine, the equivalent of 1-3 cups of coffee. At present, this synthetic caffeinated carbonated drink is popular with children, teenagers and adults around the world. Although there are no reports of harm to health, the man-made foods and drinks seem to have something to do with obesity, a major problem for young Americans. Recent data have shown that caffeine intake from carbonated drinks may be associated with high blood pressure, benzene poisoning and cancer in young people. By the late 1890s, Coca-Cola became one of the most popular carbonated drinks in the United States, and Coca-Cola's sales increased 40-fold between 1890 and 1900. Attractive advertising is one of the important factors for its success. After a hundred years of operation, it has been sold all over the United States and Canada. In the early 20th century, the company began to sell syrup to independent bottling companies to authorize it to sell drinks. Today, the huge American soft drink industry operates on this principle. Although Pemberton's original idea was to invent a health drink, a drink that nourishes the body and brain, it was an idea and did not conduct medical trials.