Bariatric surgery is the only scientifically proven method for permanent and effective weight loss. Mechanism of weight loss after this is different from other methods. Sleeve gastrectomy and diversion procedures re-set the fat set point to a lower level. This new low fat set point in turn reduce fat burden and maintain low body fat stores. Bariatric surgery is performed on stomach and small intestine. Excess fat is not removed in this method. Majority of the obese individuals fail to reduce weight by diet restriction and regular exercise. Even if they lose initially, weight is regained due to the effect of fat set point. These are benefited from bariatric surgery. Bariatric surgery is very safe and effective tool for permanent weight loss.