Sleeve Gastrectomy (SG) is a procedure that permanently reduces the size of the stomach to about 60-80 cc (half a cup). The gastric restriction makes patients lose weight because they eat less. However, it is not only the smaller size of the stomach that creates the early feeling of fullness. It is also the fact that by surgically removing 70% of the stomach along the greater curvature, the procedure takes off a part of the stomach, called fundus, that produces ghrelin, a hormone that is involved in the perception of hunger.