top of page

IFSO/ASMBS publish 1st international recommendations for BMS in over 30 years

Updated: Oct 26, 2022

The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) and the American Society for Metabolic and Bariatric Surgery (ASMBS) have published the first new guidelines of international, evidence-based guideline recommendations for bariatric and metabolic surgery (BMS) in over 30 years. The guidelines, ‘ASMBS/IFSO Guidelines on Indications for Metabolic and Bariatric Surgery - 2022’, were published in the journals Surgery for Obesity and Related Diseases (SOARD) and Obesity Surgery. The guidelines replace the 1991 consensus statement from the National Institutes of Health and include multiple changes, including expanding the patient population for metabolic and bariatric surgery to include patients with type 2 diabetes and a BMI of 30kg/m2 or greater.


Scott Shikora

“The ASMBS/IFSO Guidelines provide an important reset when it comes to the treatment of obesity,” said Dr Scott Shikora, President of IFSO. “Insurers, policy makers, healthcare providers and patients should pay close attention and work to remove the barriers and outdated thinking that prevent access to one of the safest, effective and most studied operations in medicine.”

In the 1991 consensus statement, bariatric surgery was confined to patients with a BMI of at least 40 or a BMI of 35 or more and at least one obesity-related condition such as hypertension or heart disease. There were no references to metabolic surgery for diabetes or references to the emerging laparoscopic techniques and procedures that would become mainstay and make weight-loss surgery as safe or safer than common operations including gallbladder surgery, appendectomy, and knee replacement. The statement also recommended against surgery in children and adolescents even with BMIs over 40 because it had not been sufficiently studied.

The ASMBS/IFSO Guidelines now recommend metabolic and bariatric surgery for individuals with a BMI of 35 or more “regardless of presence, absence, or severity of obesity-related conditions” and that it be considered for people with a BMI 30-34.9 and metabolic disease and in “appropriately selected children and adolescents.”

“The 1991 NIH Consensus Statement on Bariatric Surgery served a valuable purpose for a time, but after more than three decades and hundreds of high-quality studies, including randomised clinical trials, it no longer reflects best practices and lacks relevance to today’s modern-day procedures and population of patients,” said Dr Teresa LaMasters, president of the ASBMS. “It’s time for a change in thinking and in practice for the sake of patients. It is long overdue.”

Teresa LaMasters

But even without metabolic disease, the guidelines state that bariatric and metabolic surgery should be considered starting at BMI 30 for people who do not achieve substantial or durable weight loss or obesity disease-related improvement using nonsurgical methods.

It was also recommended that obesity definitions using standard BMI thresholds be adjusted by population and that Asian individuals consider weight-loss surgery beginning at BMI 27.5.

The guidelines were developed by 24 international experts in obesity, bariatric and metabolic Surgery, to provide healthcare practitioners with an overview of the current evidence-based recommendations. In summary, the guidelines include:

  • Metabolic and bariatric surgery is recommended for individuals with a BMI at or exceeding 35 kg/m2, regardless of presence, absence, or severity of co-morbidities.

  • Metabolic and bariatric surgery should be considered for individuals with metabolic disease and BMI of 30-34.9 kg/m2.

  • BMI thresholds should be adjusted in the Asian population such that a BMI at or exceeding 25 kg/m2 suggests clinical obesity, and individuals with BMI at or exceeding 27.5 kg/m2 should be offered metabolic and bariatric surgery.

  • Long-term results of metabolic and bariatric surgery consistently demonstrate safety and efficacy.

  • Appropriately selected children and adolescents should be considered for metabolic and bariatric surgery.

A large portion of the document is dedicated to special considerations for clinicians related to different patient populations. These considerations address extremes of age, those who are candidates for organ transplantation, and the high-risk patient, which included those with a BMI exceeding 60 kg/m2, cirrhosis, or heart failure.

The guidelines also noted that multiple studies have shown significant improvement of metabolic disease and a decrease in overall mortality after surgery and that “older surgical operations have been replaced with safer and more effective operations.” Two laparoscopic procedures, sleeve gastrectomy and Roux-en-Y Gastric Bypass (RYGB), now account for about 90% of all operations performed worldwide.

Roughly 1 to 2% of the world’s eligible patient population get weight-loss surgery in any given year. Experts say the overly restrictive consensus statement from 1991 has contributed to the limited use of such a proven safe and effective treatment. Globally, more than 650 million adults had obesity in 2016, which is about 13% of the world’s adult population. CDC reports over 42% of Americans have obesity, the highest rate ever in the U.S.

The ASMBS/IFSO Guidelines are just the latest in a series of new recommendations from medical groups calling for expanded use of metabolic surgery. In 2016, 45 professional societies, including the American Diabetes Association (ADA), issued a joint statement that metabolic surgery should be considered for patients with type 2 diabetes and a BMI 30.0–34.9 if hyperglycaemia is inadequately controlled despite optimal treatment with either oral or injectable medications. This recommendation is also included in the ADA’s, ‘Standards of Medical Care in Diabetes – 2022’.

To access the guidelines in SOARD, please click here


bottom of page