Bariatric surgery, also known as weight loss surgery, refers to the various surgical procedures performed to treat obesity by modification of the gastrointestinal tract to reduce nutrient intake and/or absorption. The term does not include procedures for surgical removal of body fat such as liposuction or abdominoplasty.

For individuals who have been unable to achieve significant weight loss through diet modifications and exercise programs alone, bariatric surgery may help to attain a more healthy body weight. There are a number of surgical options available to treat obesity, each with their advantages and pitfalls. In general, bariatric surgery is successful in producing (often substantial) weight loss, though one must consider operative risk (including mortality) and side effects before making the decision to pursue this treatment option.

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