Therefore, the best choice for drinking tea in winter is black tea such as Qi Hong and Dianhong, and black tea such as Pu 'er and Liubao tea. Black tea is sweet and warm, which can nourish the human yang. Black tea is rich in protein, which can nourish the body and yang. It is rich in protein and sugar, which can generate heat and warm the abdomen, enhance the cold resistance of the human body, and help digestion and get rid of greasy food. Black tea can digest meat, digest fat and regulate three major metabolism (sugar metabolism, fat metabolism and water metabolism), which is one of the reasons why ethnic minorities in border areas who are mainly meat rarely suffer from diabetes and prostate diseases. Black tea is similar to dried tangerine peel. The older, the better. It produces hundreds of precious enzymes during storage, which can benefit kidney and reduce turbidity, and has a good curative effect on nephritis and diabetic nephropathy.