The gastric sleeve, also called sleeve gastrectomy, is a bariatric surgery operation to induce weight loss. It works by reducing the size of your stomach. The word “gastrectomy” means removal of part or all of your stomach. The gastric sleeve operation removes about 80% of your stomach, leaving behind a tubular “sleeve,” about the size and shape of a banana.
Reducing the size of your stomach is a simple way to restrict the amount of food you can eat in one sitting, making you feel fuller faster. But it also serves another purpose: it reduces the amount of hunger hormones that your stomach can produce. This helps to decrease your appetite and cravings and may help to prevent the impulses that cause people to regain the weight they've lost.