The sleeve gastrectomy (SG) is a restrictive weight loss operation. The outer part of the stomach is removed and the shape of the stomach is changed from a sac to a long narrow tube (sleeve). The gastric volume is reduced from approximately 2L to 100-150 mL
The main effect of the SG is from the reduced volume of the stomach and hence only a small amount of food results in the feeling of fullness and satiety. Using the SG as a tool for portion control allows the committed patient to eat 3 small meals per day and feel satisfied, unlike being on a diet. The subsequent reduction in caloric intake will result in weight loss. Good food choices as well as regular exercise are also necessary to optimise outcome.
Recent studies have shown that the top fundus part of the stomach which produces the hunger hormone Grehlin is being removed during sleeve gastrectomy. This usually resulted in loss of hunger feeling, although it does tend to lessen with time.