At least two recent studies have found bariatric surgery more cost-effective, long term, than the pricey glucagon-like peptide 1 (GLP-1) receptor agonist obesity medications. Another recent study concluded that two leading GLP-1s are not cost-effective at current prices.
It begs the question: Should physicians suggest bariatric surgery for more of their patients with obesity?
Yes, obesity medicine experts told Medscape Medical News.
“I do think bariatric surgery is definitely underutilized, and primary care and other physicians should be thinking more often about referring their patients,” said Ryan Macht, MD, MS, an obesity medicine physician and bariatric surgeon in Belmont, California. Macht, who is also a member of the Bariatric Medical-Surgical Committee, Obesity Medicine Association, Centennial, Colorado, treats patients with both bariatric surgery and anti-obesity medications.
Despite bariatric surgery’s long track record, and the variety of surgical options, only about 1% of patients eligible for bariatric surgery actually get it, according to estimates by the American Society for Metabolic and Bariatric Surgery (ASMBS). The organization said there is an overall risk for major complications of about 4% and the risk for death at about 0.1%.
Physicians should be suggesting more patients consider bariatric surgery, but not to the exclusion of medication, Macht and others said. For some, combining medication and surgery may produce the best results. For instance, one study found that preoperative use of GLP-1s may reduce complications after bariatric surgery in those with extreme obesity.
Cost-Effectiveness: A Closer Look
In the analysis presented at the American College of Surgeons meeting in October, researchers compared the cost-effectiveness of GLP-1 medications with that of bariatric surgery. They took into account costs of the medications and the surgery and evaluated how many healthy years of life a patient could gain from the treatments, using modeling.
“Bariatric surgery and most important bariatric surgery with these medications is much more cost-effective than just taking these medications alone,” said Anne Stey, MD, assistant professor of surgery at Northwestern University Feinberg School of Medicine in Chicago and the senior author on the study.
“Bariatric surgery alone had a cost of $21,539 [on average], and 1 year of GLP-1 use was $11,935,” she said.
The medication costs would have to decline by 70% or 75%, Stey’s team found, for the cost-effectiveness to even out with surgery.
In another study, Florida researchers compared the costs between GLP-1 medications and bariatric surgery to find a break-even point. They looked at average 2023 national retail prices for GLP-1s and surgical cost estimates from 2015 adjusted for inflation.
Conclusions: “…for some GLP-1s like Saxenda and Wegovy, the high cost of ongoing use surpasses the cost of RYGB [Roux-en-Y or gastric bypass] in less than a year and sleeve gastrectomy within 9 months.”
The most affordable option studied, Byetta, becomes more costly than surgery after about 1.5 years.
University of Chicago researchers conducted a lifetime cost-effectiveness analysis using the validated Diabetes, Obesity, Cardiovascular Disease Microsimulation model for US adults. The model projected long-term cardiometabolic outcome, the amount of additional healthy years, and healthcare expenditures with the use of four anti-obesity medications, including two of the new GLP-1s, semaglutide and tirzepatide. They compared the use of the GLP-1s and lifestyle modification with that of lifestyle modification alone.
The newer GLP-1s offered long-term health benefits but weren’t cost-effective at current prices, the researchers said.
Bariatric Surgery: Increasing
In 2022, 279,967 bariatric surgeries were performed in the United States, up from 262,893 in 2021, according to the ASMBS, with sleeve gastrectomy and RYGB being the most popular ones.
Estimates of weight loss with surgery vary. Patients may lose as much as 60% of excess weight after 6 months, according to ASMBS, and 77% in as early as 12 months.
Others cite different estimates. Surgery patients can expect to lose 20%-50% of their excess weight, according to Catherine (Cate) Varney, DO, obesity medicine director for University of Virginia Health, Charlottesville, Virginia, and a primary care and obesity medicine doctor at its comprehensive bariatric surgery center.
In comparison, she tells patients, weight loss using diet and lifestyle averages 5%-10%, and up to 20% for obesity medicines.
Tracking bariatric surgery patients long term to assess success is difficult for researchers, said Ann M. Rogers, MD, director of the Surgical Weight Loss Program, Penn State Health, and president of the ASMBS, because so many patients are lost to follow-up. She contends that’s because many who do well don’t keep in contact with their doctors.
She cited a study done in 2016, when researchers compared the outcomes of 151 patients with consistent 10-year follow-up with those of 500 patients who submitted data for the study. Researchers found no difference in weight-loss outcomes between the groups, with the research refuting claims that those lost to follow-up gain back the weight.
“A lot of commercial insurance companies do cover bariatric surgery,” Rogers said, but often requires patients first to spend 6-12 months in a lifestyle weight-loss program. She sees a trend to major insurers becoming more stringent with this requirement.
GLP-1’s Track Record
While weight loss with the GLP-1s varies person to person and with different medications, the SURMOUNT-5 phase 3b, open-label, randomized clinical trial found tirzepatide (Zepbound) produces a loss of 20.25% vs 13.7% with semaglutide (Wegovy).
Yet discontinuation rates are high, with users citing costs and side effects. In a retrospective cohort study of 125,474 adults with overweight or obesity who started a GLP-1 (liraglutide, semaglutide, or tirzepatide) between January 1, 2018, and December 31, 2023, most discontinued the medication within a year. Those without type 2 diabetes, taking the medication for overweight or obesity, were more likely to stop the medication and less likely to restart it.
In 2024, just 18% of large firms offering health benefits covered GLP-1s for obesity, which can cost $1000 per month out of pocket without coverage. And on April 7, the Centers for Medicare & Medicaid Services announced it would not be moving forward with a proposal suggested under the Biden administration to cover the medications under its Part D drug program.
Broaching the Surgery Idea
The topic of bariatric surgery does come up in visits, primary care and obesity medicine physicians said. “Most of the patients who seek my care have considered bariatric surgery but want to see if medical weight loss in an option first,” said Sarah Stombaugh, MD, a family medicine and obesity medicine physician in Charlottesville, Virginia.
“As we’ve seen the effectiveness of weight-loss medications improve, there are many patients who may think ‘Let me try medications first, and if that doesn’t work, then I’ll consider surgery.’”
“While the complication rates from bariatric surgery have improved significantly over the past few decades, it is still a major surgery,” Stombaugh said.
Varney recalled a patient considering surgery who was nervous about the risks. When the patient mentioned a previous surgery (not related to obesity) that had gone well, Varney told her the bariatric surgery risks were the same or less than those of her prior surgery. “She had the surgery and did great,” she said, achieving a body mass index of 24.
Rogers describes GLP-1s as a “gateway drug,” explaining that people who would not have considered obesity treatment might now consider medications, with the arrival of the GLP-1s. Then, if the medications stop working, “they might consider surgery,” which they would not have considered otherwise.
Macht and Stey had no disclosures. Rogers is a proctor and/or speaker for Intuitive Surgical, Medtronic, and W.L. Gore. Stombaugh is on the Lilly faculty for Zepbound. Varney was on a primary care advisory board for Eli Lilly in 2024.
Kathleen Doheny is a freelance journalist in Los Angeles.