For obese people, diet and exercise will almost always reduce weight, but almost always rebound without exception, so why diet and exercise can not lose weight successfully? When you exercise after work, etc., the body needs calories but can not get them, it will choose to slow down the metabolism in order to reduce the consumption of energy, rather than through a complex biochemical reaction, the body’s fat into energy. So eating less will only be our body to reduce consumption, and not help us reduce fat. At the same time, dieting for a long time, the body thinks that the famine is coming, will find ways to accumulate fat, muscle loss, the basal metabolic rate will slow down, so once the diet can not be maintained, even if it is just eating the same food as before, the body will think it is eating too much, the extra calories will be converted into fat storage, the result is that you are fatter than before. After a person has recovered from a famine, his body will find ways to store more fat in case of the next famine. The energy burned by exercise is often offset by the subsequent increase in calorie intake. Each person’s metabolism has a tuning point, and those with fast metabolism have a lower tuning point than those with slower heart sink metabolism. This point does not depend on the amount of calories consumed or consumed. Weight gain is the point at which the adjustment point rises, when the hormones of our metabolism change and the adjustment point of our weight rises. Therefore, the lack of success in losing weight is not only due to the lack of human willpower, he has physiological reasons, so it is important to eat the right food and choose the right exercise method in order to lower the adjustment point and lose weight. For obese patients, almost all have insulin resistance, that is, hyperinsulinemia, insulin is produced by the pancreas, which determines whether the body stores fat or burns fat, when glucose is elevated in the blood, the secretion of insulin will increase for the absorption of glucose, too much glucose in the cells, it will be converted into fat, and for obese patients, eat too much, glucose in the blood is elevated very quickly. The pancreas will release large amounts of insulin, leading to hyperinsulinemia. With too much insulin, the cells do not burn fat. With high insulin and more blood sugar, the effect of leptin is affected, and even though there is already a lot of fat, the person’s appetite is not affected and there is no desire to exercise, so the weight set point is raised. A large number of follow-up studies have shown that for patients with severe obesity either a low calorie diet or diet control plus exercise will reduce weight, but by 5 years later will almost always regain weight, and as long as they lose weight once, rebound will occur, resulting in more and more weight loss. Therefore, diet and exercise are ineffective for weight reduction in patients with severe obesity. Therefore, for patients with severe obesity, weight reduction after surgery will reduce the caloric adjustment point of the patient, make the diet control easier and the hyperinsulinemia is relieved. Thus, the long-term effect of weight control is achieved.