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Surgery for obesity

When other weight-loss measures don't work, surgery may be an option.

If you're obese and your efforts to lose weight always seem to come up short, surgical solutions may be an option.

Three types of surgery—gastric band, gastric sleeve and gastric bypass operations—can help people who are obese lose weight and reduce their risk of serious illnesses such as diabetes, heart disease and high blood pressure, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Obesity defined

For most types of surgery, candidates must have:

  • A body mass index (BMI) of 40 or more.
  • A BMI of 35 or more and a serious obesity-related health problem such as type 2 diabetes, coronary heart disease or severe sleep apnea (when breathing stops for short periods during sleep).
  • A BMI of 30 or more with type 2 diabetes that is difficult to control with lifestyle changes and medical treatments.

You can check your BMI using our calculator.

Some people may be able to lose weight through diet and exercise, but others may need more aggressive therapy such as surgery.

Making the stomach smaller

Two types of surgeries restrict the size of the stomach, which help you feel full sooner.

In gastric band surgery, an inflatable band is wrapped around the top of the stomach, which creates a small pouch. The band can be adjusted or reversed.

In gastric sleeve surgery, 80% of the stomach is permanently removed. The stomach is stapled shut.

Creating a shortcut

In gastric bypass operations, surgeons use staples to create a small pouch at the top of the stomach, helping you feel full sooner. Then they attach the lower part of the small intestine to the pouch, creating a bypass around the rest of the stomach and top of the intestine. With the bypass, the body absorbs fewer calories.


Although surgery may seem like a simple solution to a difficult problem, you should be aware that it is a serious undertaking, according to the NIDDK.

Risks include hernias, gallstones and nutritional deficiencies. Some people who have weight-loss surgeries need follow-up operations to correct complications.

Many find benefits

But there are benefits. One study found that people undergoing adjustable gastric banding, gastric sleeve or gastric bypass lost between 38 and 87 pounds—and while most regained some weight, the amount was usually small.

Surgery also improves most obesity-related conditions. In fact, it's very effective at helping obese people with diabetes control their blood sugar levels—they may even return to normal.

Although surgery does help people lose weight, it's just as important to change your lifestyle and work with your healthcare team after the operation.

Talk to your doctor if you want more information about surgery for obesity.

Reviewed 12/6/2023

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