Applied Evidence

Obesity: When to consider surgery

Department of Internal Medicine, New York-Presbyterian Hospital/Weill Cornell Medical College, New York, NY (Dr. Barenbaum); Comprehensive Weight Control Center, Division of Endocrinology, Diabetes and Metabolism, Weill Cornell Medicine, New York, NY (Drs. Saunders, Igel, Shukla, and Aronne)

Dr. Aronne serves as a consultant to Eisai Co., Gelesis, GI Dynamics, Jamieson Laboratories, Janssen, Novo Nordisk, Pfizer, Real Appeal, Inc., and UnitedHealth Group Ventures; receives grant/research support from Aspire Bariatrics, AstraZeneca, and Eisai Co.; has an equity interest in BMIQ, Gelesis, Jamieson Laboratories, MYOS RENS Technology Inc., and Zafgen, Inc.; and serves on the board of directors of BMIQ, Jamieson Laboratories, and MYOS RENS Technology Inc.

Drs. Barenbaum, Saunders, Igel, and Shukla reported no potential conflict of interest relevant to this article.

Bariatric surgery is underutilized despite an obesity epidemic. Here, 3 patients pursue a surgical option when they can't reach their target weight and optimal health by nonsurgical means.


Among adult patients with body mass index* ≥40, or ≥35 with obesity-related comorbid conditions:

› Consider bariatric surgery in those who are motivated to lose weight but who have not responded to lifestyle modification with or without pharmacotherapy in order to achieve sufficient and sustained weight loss. A

› Consider bariatric surgery to help patients achieve target health goals and reduce/improve obesity-related comorbidities. A

Strength of recommendation (SOR)

A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series

*Calculated as weight in kilograms divided by height in meters squared.



Patients with overweight and obesity are at increased risk of multiple morbidities, including cardiovascular disease, stroke, type 2 diabetes (T2D), osteoarthritis, obstructive sleep apnea (OSA), and all-cause mortality.1 Even modest weight loss—5% to 10%—can lead to a clinically relevant reduction in this risk of disease.2,3 The American Academy of Family Physicians recognizes obesity as a disease, and recommends screening of all adults for obesity and referral for those with body mass index (BMI)* ≥30 to intensive, multicomponent behavioral interventions.4,5

Obesity: When to consider surgery

For some patients, diet, exercise, and behavioral modifications are sufficient; for the great majority, however, weight loss achieved by lifestyle modification is counteracted by metabolic adaptations that promote weight regain.6 For patients with obesity who are unable to achieve or maintain sufficient weight loss to improve health outcomes with lifestyle modification alone, options include pharmacotherapy, devices, endoscopic bariatric therapies, and bariatric surgery.

Bariatric surgery is the most effective of these treatments, due to its association with significant and sustained weight loss, reduction in obesity-related comorbidities, and improved quality of life.1,7 Furthermore, compared with usual care, bariatric surgery is associated with a reduced number of cardiovascular deaths, a lower incidence of cardiovascular events in adults with obesity, and a long-term reduction in overall mortality.8-10

What are the options? Who is a candidate?

The 3 most common bariatric procedures in the United States are sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and laparoscopic adjustable gastric band (LAGB).11 SG and RYGB are performed more often than the LAGB, consequent to greater efficacy and fewer complications.12 Weight loss is maximal at 1 to 2 years, and is estimated to be 15% of total body weight for LAGB; 25% for SG; and 35% for RYGB.13,14

Weight loss is estimated to be 15% of total body weight for the laparoscopic adjustable gastric band, 25% for sleeve gastrectomy, and 35% for Roux-en-Y gastric bypass.

Not all patients are candidates for bariatric surgery. Contraindications include chronic obstructive pulmonary disease or respiratory dysfunction, poor cardiac reserve, nonadherence to medical treatment, and severe psychological disorders.15 Because some patients have difficulty maintaining weight loss following bariatric surgery and, on average, patients regain at least some weight, patients must understand that long-term lifestyle changes and follow-up are critical to the success of bariatric surgery.16

When should bariatric surgery be considered?

American Heart Association/American College of Cardiology/The Obesity Society guidelines16 conceptualize 2 indications for bariatric surgery:

  • adults with BMI ≥40
  • adults with BMI ≥35 who have obesity-related comorbid conditions and are motivated to lose weight but have not responded to behavioral treatment, with or without pharmacotherapy, to achieve sufficient weight loss for target health goals.

American Association of Clinical Endocrinologists guidelines17 conceptualize 3 indications for bariatric surgery:

  • adults with BMI ≥40
  • adults with BMI ≥35 with 1 or more severe obesity-related complications
  • adults with BMI 30-34.9 with diabetes or metabolic syndrome (evidence for this recommendation is limited).

Continue to: The 3 illustrative vignettes presented...


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