Bariatric surgery

Bariatric surgery (also known as metabolic surgery or weight loss surgery) is a group of surgical procedures used to manage obesity and related conditions. Long-term weight loss with bariatric surgery may be achieved through alteration of gut hormones, physical reduction of stomach size, reduction of nutrient absorption, or a combination of these. Standard of care procedures include Roux en-Y bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch, from which weight loss is largely achieved by altering gut hormone levels responsible for hunger and satiety, leading to a new hormonal weight set point.

In morbidly obese people, bariatric surgery is the most effective treatment for weight loss and reducing complications. A 2021 meta-analysis found that bariatric surgery was associated with reduction in all-cause mortality among obese adults with or without type 2 diabetes. This meta-analysis also found that median life-expectancy was 9.3 years longer for obese adults with diabetes who received bariatric surgery as compared to routine (non-surgical) care, whereas the life expectancy gain was 5.1 years for obese adults without diabetes. The risk of death in the period following surgery is less than 1 in 1,000. Bariatric surgery may also lower disease risk, including improvement in cardiovascular disease risk factors, fatty liver disease, and diabetes management.

Stomach reduction surgery is frequently used for cases where traditional weight loss approaches, consisting of diet and physical activity, have proven insufficient, or when obesity already significantly affects well-being and general health. These procedures involve reducing food intake. Some procedures may also reduce the absorption of carbohydrates, fats, calories, and protein. The outcome is typically a significant reduction in BMI. The efficacy of stomach reduction surgery varies depending on its specific type. There are two primary divisions: gastric sleeve surgery and gastric bypass surgery.

As of October 2022, the American Society of Metabolic and Bariatric Surgery and the International Federation for the Surgery of Obesity recommended consideration of bariatric surgery for adults meeting two specific criteria: those with a body mass index (BMI) of more than 35 whether or not they have an obesity-associated condition and those with a BMI of 30–35 who have metabolic syndrome. However, these designated BMI ranges do not hold the same meaning in particular populations, such as among Asians, for whom bariatric surgery may be considered when a BMI is more than 27.5. Similarly, the American Academy of Pediatrics recommends bariatric surgery for adolescents 13 and older with a BMI greater than 120% of the 95th percentile for age and sex.