In this method, 2/3 of the stomach is removed laparoscopically. Normally, the volume of the stomach is 800-1000 ml. After sleeve gastrectomy, the stomach volume is reduced by 250-300 ml. This means that the patient can only eat 1/4 of what he or she could eat before the surgery. Another effect of sleeve gastrectomy is the decrease in the feeling of hunger after the operation. The hormone (Ghrelin), which gives the feeling of hunger, is largely secreted from the removed part of the stomach. Therefore, the level of Ghrelin hormone decreases after the surgery and thus the appetite.