In the battle with obesity, many people have experienced “weight loss – re-fat”, and some have even experienced several rounds of repeated weight loss, falling deeply into the strange circle of re-fat a kind of buttermilk effect. When weight loss surgery is becoming more and more popular, its long-term effectiveness is recognized by many friends, so how exactly does weight loss surgery break the circle of “re-fat”? Weight loss surgery is a kind of gastrointestinal surgery, it is through adjusting the human gastrointestinal structure, limiting the body’s food intake and absorption, so as to achieve the effect of weight loss. So how does it solve the problem of “re-fat” and achieve long-term effectiveness? Here I would like to introduce a new concept “body fat adjustment point” to you. In fact, our bodies have a “body fat adjustment point” that varies from person to person. Most of us have a fixed body fat set point, so because of the existence of the weight set point, short-term weight gain or loss will automatically compensate for it, and the weight will tend to return to the set point level. Therefore, if we rely on lifestyle, dietary changes, or medication interventions, we will have little effect on the change of the body fat adjustment point; if we rely on dieting alone, we will not be able to lower the body fat adjustment point, which will lead to the result of “re-fat”. After the surgery, by changing the structure of the gastrointestinal tract, the normal body fat adjustment point can be adjusted, and when the adjustment point decreases after the surgery, the problem of “regained weight” can be solved fundamentally.