Indications for Metabolic and Bariatric Surgery

Clinical practice guidelines endorsed by the American Society for Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) recommend metabolic and bariatric surgery (MBS) for appropriately selected adults living with obesity, including:

BMI ≥ 35 kg/m², regardless of the presence of obesity-related diseases
BMI 30 - 34.9 kg/m² in the presence of type 2 diabetes or other obesity-related conditions that have not adequately improved with non-surgical medical treatment

People of Asian ethnicity may develop type 2 diabetes and cardiovascular disease at lower BMI values. For this reason, lower BMI thresholds for MBS may be appropriate in these populations. This highlights the importance of an individualized, comprehensive evaluation, rather than reliance on BMI alone.

Metabolic and bariatric surgery may also be considered as a preparatory (bridging) treatment to reduce surgical risk and improve outcomes before other necessary procedures, such as:

Abdominal wall hernia repair
Joint arthroplasty
Solid organ transplantation

Who May Not Be Appropriate Candidates for Surgery at This Time?

Metabolic and bariatric surgery may be deferred or contraindicated in individuals with:

Age outside the limits defined by national or institutional regulations
Medical conditions in which the risks of surgery outweigh the potential benefits
Certain uncontrolled diseases that could compromise safety (e.g., active inflammatory bowel disease or other uncontrolled autoimmune conditions)
Active substance use disorder
Pregnancy
Limited ability to understand the procedure, its risks, benefits, and long-term implications, despite appropriate education and support

These factors are assessed as part of a multidisciplinary evaluation, and many may be temporary or modifiable with appropriate care.