Sleeve gastrectomy (SG) reduces the volume of the stomach to about 25% of its original size. The procedure involves removing two-thirds of the stomach along its length, so it looks like a long tube. The smaller stomach tube remains attached to the bowel, thus ensuring proper nutrient absorption. SG is a restrictive procedure: it minimizes food intake, reducing hunger and increasing satiety. It works by modifying the secretion of hormones from the digestive tract that send hunger and satiety signals to the brain, decreasing the production of the former, and increasing that of the latter. In some patients, it can also change tastes, acting not only on the amount of food but also on the quality, so helping people to avoid high-calorie foods. SG is effective against Type 2 Diabetes and can worsen gastroesophageal reflux; it generally has fewer potential complications than gastric bypass surgery.