The correct way to lose weight should be to reduce the fat in adipose tissue, each gram of fat will produce 9 calories, so if you want to reduce 1 kg of fat, you must consume 7700 calories from a medical point of view. If you reduce 500 calories a day, it will take 14 days to reduce 1 kg; If you lose 1000 calories a day, it will take seven days to lose 1 kg. However, people have metabolism every day and must have the most basic calorie intake to maintain the needs of the body. Generally speaking, boys need 1600 calories a day and girls need 1200 calories.