Weight loss weight is not lost but the circumference is smaller and the abdominal circumference is reduced, probably because the percentage of muscle is increased. The density of fat is relatively low, the same weight of fat and muscle, muscle volume is much smaller than fat. The decrease in circumference at the same weight is due to a decrease in body fat and an increase in muscle mass, which in common parlance means that the meat has become “tighter”. When the body’s muscle content is high, the amount of protein is relatively high. Weight loss is mainly based on the body fat percentage, it is possible to lose 5kg of fat and gain 5kg of muscle, although the numerical weight has not changed, but the body fat percentage has dropped a lot, the whole person’s circumference and appearance will also look much thinner. Obese people should reduce weight reasonably under the guidance of doctors.