Bariatric surgery outdoes GLP-1 RAs for weight loss

Patients with obesity achieve greater weight loss with bariatric surgery than glucagon-like peptide-1 receptor agonists (GLP-1 RAs) semaglutide and tirzepatide, a study has shown.

A total of 44,025 patients were included in the analysis. Bariatric surgery correlated with greater weight loss at 1, 2, and 3 years post-treatment. Sleeve gastrectomy (n=8,728) total weight loss (TWL) was 24.4 percent, 22.4 percent, and 22.0 percent, respectively, while the corresponding TWL with gastric bypass (n=2,185) was 29.8 percent, 28.1 percent, and 28.4 percent.

For the GLP-1 RAs, semaglutide (n=25,804) TWL was 5.4 percent, 6.5 percent, and 7.4 percent at 1, 2, and 3 years, respectively. TWL with tirzepatide (n=7,308) was 9.1 percent and 10.8 percent. With 1 year of continuous GLP-1 RA, semaglutide TWL was 7.2 percent, 8.0 percent, and 8.8 percent, while that for tirzepatide was 11.7 percent and 11.9 percent.

“In this retrospective two-centre study, bariatric surgery was associated with greater weight loss than GLP-1 RAs among patients eligible for both options,” the authors said.

The study included adults with BMI ≥35 kg/m² who received injectable GLP-1 RAs (semaglutide or tirzepatide) or bariatric surgery (sleeve gastrectomy or gastric bypass) at two urban health systems from 2018 to 2024. The authors then compared TWL up to 3 years post-treatment using inverse probability weighting and mixed linear models. They also performed intention-to-treat and per-protocol analyses.