Network meta-analysis finds metabolic surgery superior to GLP-1 agonists for weight loss in obesity

This network meta-analysis included 20,015 adults with overweight or obesity, comparing metabolic/bariatric surgery (MBS), GLP-1 receptor agonists (including dual GLP-1/GIP analogues like tirzepatide), and lifestyle intervention. The analysis synthesized data from randomized controlled trials, with follow-up periods categorized as less than 104 weeks and 104 weeks or more. The primary outcomes were percent total weight loss and BMI, with secondary outcomes including body weight, waist circumference, HbA1c, and systolic blood pressure.

MBS demonstrated superior efficacy compared to GLP-1 receptor agonists across multiple outcomes. For percent total weight loss, MBS achieved a -10.3% greater reduction (p=0.001), with differences remaining significant at -9.1% (p=0.022) in longer-term analyses. Body weight reductions favored MBS by -11.7 kg (p<0.001) and -14.6 kg (p=0.049) in shorter and longer follow-ups, respectively. BMI decreased by -4.5 kg/m² more with MBS (p<0.001), and waist circumference by -12.6 cm (p<0.001). HbA1c improved by -0.5% more with MBS (p=0.033).

In tirzepatide-only analyses, differences versus MBS were not statistically significant. Among participants with type 2 diabetes, MBS produced greater reductions in BMI, weight, waist circumference, and percent total weight loss, with similar HbA1c improvement compared to GLP-1 agonists. Safety and tolerability data were not reported in the analysis. Limitations include the indirect nature of comparisons from network meta-analysis, which may introduce bias, and lack of reported safety outcomes. The findings suggest MBS remains superior for weight-related outcomes, but tirzepatide shows promise as a nonsurgical option, supporting personalized approaches in obesity management.