The American Beverage Guidance Expert Group issued a guide to classify beverages into six grades:

Grade I: drinking water. The best drink to replenish the water needed by the human body every day;

Grade two: tea and coffee. Green tea, oolong tea and black tea are three kinds of teas that are often drunk. Tea can provide antioxidant substances such as tea polyphenols and some micronutrients, and has the functions of preventing and treating cancer, reducing the risk of cardiovascular diseases, increasing bone density, reducing tooth decay and dental caries and kidney calculi. Coffee has a refreshing effect;

The third grade: low-fat milk, skimmed milk, soybean beverage. It is an important source of high-quality protein, calcium and some essential micronutrients needed by human body, and yogurt also contains bacteria beneficial to human body.

Grade 4: Sweet beverage without calories. Only provide moisture and sweetness, not energy;

Grade 5: beverages containing certain nutrients. Refers to pure fruit and vegetable juice, whole milk, alcoholic drinks and sports drinks;

Grade 6: sweet drinks with calories. This drink contains almost no other useful nutrients except high energy.