Make a bag at a time, it is best to make a bag with only one glass of water and drink a cup of strong tea at a time (the stronger the better). Drink 2 ~ 3 packs a day on an empty stomach (one pack before meals and one pack before going to bed at night), so you don't have to go on a diet, because after drinking for a while, your hobbies for food will naturally change, and many people don't like dirty and greasy food very much. Put a bag of tea in a teapot or teacup, and pour boiling water to drink. It is best to stew for 5 ~ 6 minutes, so that the tea leaves will be thicker. Moreover, even if the tea is cold, the effect will not change, and it tastes better after being chilled in summer.