Types of Weight-loss Surgery - NIDDK (2024)

In this section:

• What are the surgical options?
• How is the surgery performed?
• What should I expect before surgery?
• What should I expect after surgery?
• How much weight can I expect to lose?

The type of weight-loss surgery, also called metabolic and bariatric surgery, that may be best to help a person lose weight depends on a number of factors. You should discuss with your doctor what kind of surgery might be best for you.

What are the surgical options?

In the United States, surgeons most often perform three types of operations

• gastric sleeve
• gastric bypass
• adjustable gastric band

Surgeons less commonly use a fourth operation, biliopancreatic diversion with duodenal switch.

Gastric sleeve

In gastric sleeve surgery, also called vertical sleeve gastrectomy, a surgeon removes most of your stomach, leaving only a banana-shaped section that is closed with staples. The surgery reduces the amount of food that can fit in your stomach, making you feel full sooner. Taking out part of your stomach may also affect hormonesor bacteria in the gastrointestinal system that affect appetite and metabolism. This type of surgery cannot be reversed because some of the stomach is permanently removed.

Gastric bypass

Gastric bypass surgery, also called Roux-en-Y gastric bypass, is done in three steps. First, the surgeon staples your stomach, creating a small pouch in the upper section. The staples make your stomach much smaller, so you eat less because you feel full sooner.

Next, the surgeon divides your small intestine into two parts and attaches the lower part directly to the small stomach pouch. Food will bypass most of your stomach and the upper part of your small intestine, so your body absorbs fewer calories.

The surgeon then reconnects the upper part of the small intestine to a new location farther down on the lower part of the small intestine. This allows digestive juices in the stomach to flow from the bypassed part of the small intestine to the lower part of the small intestine, so that food can be fully digested. The bypass changes hormones, bacteria, and other substances in the gastrointestinal tract that may affect appetite and metabolism. Gastric bypass is difficult to reverse, although a surgeon may do it if medically necessary.

Adjustable gastric band

In this type of surgery, the surgeon places a ring with an inner inflatable band around the top of your stomach to create a small pouch. Like gastric sleeve and gastric bypass surgery, the gastric band makes you feel full after eating a small amount of food. The inner band has a circular balloon inside that is filled with saline solution. The surgeon can adjust the inner band to resize the opening from the pouch to the rest of your stomach by injecting or removing the saline solution through a small device, called a port, that is placed under your skin.

After surgery, you will need several follow-up visits to adjust the size of the band opening. If the band causes problems or is not helping you lose enough weight, the surgeon may remove it.

Today, adjustable gastric band surgery is less commonly performed in the United States, compared with the gastric sleeve or gastric bypass, because it is associated with more complications, predominantly the need for band removal due to intolerance.⁵ Gastric band surgery also typically results in significantly less weight loss and is associated with more complications, predominately the need for band removal due to intolerance.⁵

Biliopancreatic diversion with duodenal switch

A surgical procedure called biliopancreatic diversion with duodenal switch, or “mixed surgery,” involves two separate procedures. The first procedure is similar to gastric sleeve surgery. A second surgical procedure divides the small intestine into two tracts. Food moves through one tract, bypassing most of the small intestine. This reduces the number of calories and amount of nutrients absorbed. Digestive juices flow from the stomach through the other intestinal tract and mix with food as it enters the colon.

This type of surgery allows you to lose more weight compared with the other three operations described above. However, it is also the most likely to cause surgery-related problems and a shortage of vitamins, minerals, and proteins in your body. For these reasons, surgeons do not perform this particular procedure often. However, some surgeons may recommend it for patients who have severe obesity and certain health conditions.

Most Common Weight-loss Surgeries

Adapted from: Bariatric surgery procedures. American Society for Metabolic and Bariatric Surgery (ASMBS). Accessed October 5, 2020. https://asmbs.org/patients/bariatric-surgery-procedures. Image credit: Walter Pories, M.D., FACS.

How is the surgery performed?

Weight-loss surgery is mostly done laparoscopically, which requires only small cuts, under general anesthesia. Through these incisions, the surgeon can insert thin tools and a small scope attached to a camera that projects images onto a video monitor. Laparoscopic surgery has fewer risks than open surgery and may cause less pain and scarring. Recovery may also be faster with laparoscopic surgery.

Open surgery, which involves a single, large cut in the abdomen, may be a better option than laparoscopic surgery for certain people. You may need open surgery if you have a high level of obesity, had stomach surgery before, or have other complex medical problems.

What should I expect before surgery?

Before surgery, you will meet with several health care professionals, such as an internist, a dietitian, a psychiatrist or psychologist, and a bariatric surgeon.

• The internist will ask about your medical history, perform a thorough physical exam, and order blood tests. If you smoke, you may benefit from stopping smoking at least 6 weeks before your surgery.
• The dietitian will explain what and how much you will be able to eat and drink after surgery and help you prepare for how your life will change after surgery.
• The psychiatrist or psychologist may assess you to see if you are ready to manage the challenges of weight-loss surgery.
• The surgeon will tell you more about the surgery, including how to prepare for it and what type of follow-up you will need.

These health care professionals also will advise you to become more active and adopt a healthy eating plan before and after surgery. Losing weight and bringing your blood glucose—also known as blood sugar—levels closer to normal before surgery may lower your chances of having surgery-related problems.

Some weight-loss surgery programs have groups you can attend before and after surgery to help answer questions about the surgery and offer support.

What should I expect after surgery?

After surgery, you will need to rest and recover. Walking and moving around the house may help you recover more quickly. Start slowly and follow your health care professional’s advice about the type of physical activity you can do safely. As you feel more comfortable, add more physical activity.

After surgery, you will probably be started on a liquid diet. Over several weeks, you will move to a soft diet that includes such foods as cottage cheese, yogurt, or soup. Eventually you will begin consuming solid foods again. Your health care professional will tell you which foods and beverages you may have and which ones you should avoid. You will need to eat small meals and chew your food well. You will need to take dietary supplements that your health care professional prescribes to make sure you are getting enough vitamins and minerals.

How much weight can I expect to lose?

The number of pounds people lose after weight-loss surgery depends on the individual and on the type of surgery. One study found that after 1 year, people undergoing adjustable gastric banding, gastric sleeve, and gastric bypass lost between 38 and 87 pounds. Of the three most common procedures, gastric bypass produced greater weight loss, on average, but had more complications in the month after surgery. Most people regained some weight over time, but that amount was usually small compared with their initial weight loss.⁶

Your weight loss could be different. Remember, reaching your goal depends not only on the surgery but also on sticking with healthy lifestyle habits.

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