context: Weight loss surgery can be lifesaving for some people who have a lot of weight to lose and need more than diet and exercise. Depending on the operation, they often lose 30% to 50% of their extra weight within 6 months. It's a big decision. You can't eat as much afterward, and it takes a life-long commitment to diet and exercise to keep the pounds off. Because it's major surgery, there are some risks, too. You and your doctor should talk through the options and decide what's right for you. First, you'll want to know what to expect. Some weight loss surgeries prevent the stomach from stretching to full size. Normally, it can hold about 6 cups of food. After some operations, it can only hold a cup or so. You feel full faster, so you eat less and lose weight. Some surgeries also bypass part of the intestine, so you absorb fewer calories and lose weight. Today, most weight loss surgeries use small cuts -- known as âlaparoscopicâ surgery -- instead of a big one. The surgeon makes five to six of these small cuts in the belly. He inserts tiny tools and a camera through these holes, then operates while watching a video screen. If that's not possible, he may need to make one large cut along the middle of the belly. Roux-en- Y Gastric Bypass Surgery This is one of the most common weight loss surgeries and is the most common procedure used for gastric bypass. During this surgery, the surgeon first divides the stomach into two parts, one large and one small. He then staples the small stomach portion to make a small pouch. Next, he disconnects the stomach pouch from the first part of the small intestine (the duodenum). Then he reconnects the stomach to the second part of the small intestine (the jejunum). This is the bypass. After gastric bypass, you feel fuller after eating less food, so you lose weight. The bypass also makes you absorb fewer calories, so you drop more pounds. Laparoscopic Adjustable Gastric Banding With this procedure, the surgeon uses laparoscopic tools to place an inflatable silicone band around the upper stomach. He tightens the band so the stomach becomes a small pouch with a narrow outlet. The result is that you feel full faster, so you eat less and lose weight. The surgeon can tighten or loosen the band, or even reverse the procedure, as needed. Gastric â Sleeveâ Surgery In this operation, your surgeon will take out most of your stomach and shape your remaining stomach into a tube, or âsleeveâ shape. It will remain attached to your small intestine. After the surgery, your stomach will be able to hold only about 2-3 ounces of food. You'll feel full sooner because your stomach is smaller. You also won't be as hungry because most of the tissue that makes the "hunger hormone," called ghrelin, will be gone. This procedure is permanent. You cannot get it reversed. Biliopancreatic Diversion This operation is like Roux-en- Y gastric bypass, except that it connects the small stomach pouch farther down in the intestine. Few weight loss surgery centers do this type of surgery. It's very effective, but it's hard to do, and it can leave you short on nutrients. Vertical Banded Gastroplasty The surgeon makes a small stomach pouch using staples and a plastic band. People lose less weight with this operation than with other surgeries. This procedure isn't as common as it used to be. Roux-en- Y gastric bypass and gastric sleeve have mostly replaced it. Ask your doctor how much weight you're likely to lose and what you'll need to do to keep up the results. Expect to eat very small meals and get regular exercise. Like any major surgery, there are risks. The most common complications occuring soon after surgery include infections, minor bleeding, and blockages or leaks in the bowel, with some of these complications requiring surgery. It's rare, but there can be life-threatening problems, such as blood clots, major bleeding, heart attack, or serious infections. These risks may be higher at surgical centers that don't do weight loss operations often. Most people stay in the hospital 2 to 3 days after their surgery. They tend to get back to their normal activities within 2 to 3 weeks.