Bariatric surgery yields greater long-term weight loss than GLP-1 receptor agonists in adults with obesity

BACKGROUND: The comparative effectiveness of bariatric surgery (BS) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for weight loss among patients with obesity remains uncertain. METHODS: MEDLINE, EMBASE and CENTRAL were searched to 5 October 2025. Pooled mean differences (MDs) for change in weight, body mass index (BMI), glycaemic indices, lipid profile and blood pressure were calculated using random-effects models with heterogeneity quantified by I. Outcomes were assessed separately according to time duration. Meta-regression was performed for the primary outcome of change in BMI. RESULTS: Fifteen studies (20 594 participants) were included. Weight loss did not differ significantly at 6 months (MD -12.19 kg; p = 0.13), but favoured BS at ≤ 1 year (MD -16.97 kg; p = 0.02) and > 1 year (MD -19.78 kg; p < 0.001). BMI reduction consistently favoured BS at 6 months (MD -6.77 kg/m; p = 0.02), ≤ 1 year (MD -5.10 kg/m; p < 0.001) and > 1 year (MD -6.61 kg/m; p < 0.001). HbA1c reduction was greater with BS beyond one year (MD -1.69%; p < 0.001), and fasting glucose was lower overall with BS (MD -1.22 mmol/L; p = 0.03). Serum lipids and blood pressure showed no significant between-group differences. Meta-regression demonstrated larger BMI reductions with BS in older patients, male patients and those with higher baseline BMI. CONCLUSION: Although substantial heterogeneity was present, BS was associated with greater and sustained reductions observed over multi-year follow up in weight, BMI and glycaemic indices compared to GLP-1 RAs, with similar effects on serum lipids and blood pressure, supporting its use in appropriately selected adults with obesity.