Network meta-analysis of RCTs comparing metabolic/bariatric surgery (RYGB, sleeve gastrectomy, gastric banding) and GLP-1 RAs (including tirzepatide) versus lifestyle intervention for percent total weight loss, BMI, HbA1c, and blood pressure using random-effects models. Provides a unified comparative evidence hierarchy from diet alone through surgery. Delivers the definitive NMA positioning tirzepatide within the full spectrum of obesity interventions including bariatric surgery—quantifying whether tirzepatide achieves surgical-level weight loss for specific populations and informing shared decision-making about treatment intensity.
Abstract
OBJECTIVE: This study compared the efficacy of metabolic/bariatric surgery (MBS) and GLP-1 receptor agonists (GLP-1 RAs), including dual GLP-1/GIP analogues, for weight and metabolic outcomes in adults with obesity.
METHODS: A network meta-analysis of randomized controlled trials compared MBS or GLP-1 RAs versus lifestyle intervention in adults with overweight or obesity. Primary outcomes were percent total weight loss (TWL) and BMI; secondary outcomes included body weight, waist circumference, HbA1c, and systolic blood pressure. Random-effects models used lifestyle intervention as the common comparator; all MBS versus GLP-1 RA comparisons were indirect.
RESULTS: Thirty randomized controlled trials (n = 20,015) were included. At < 104 weeks, MBS achieved greater reductions than GLP-1 RAs in %TWL (ETD -10.3%; p = 0.001), BMI (-4.5 kg/m; p < 0.001), body weight (-11.7 kg; p < 0.001), waist circumference (-12.6 cm; p < 0.001), and HbA1c (-0.5%; p = 0.033). At ≥ 104 weeks, differences remained for %TWL (-9.1%; p = 0.022) and body weight (-14.6 kg; p = 0.049). In tirzepatide-only analyses, differences versus MBS were not significant. Among participants with type 2 diabetes, MBS produced greater reductions in BMI, weight, waist, and %TWL, with similar HbA1c improvement.
CONCLUSIONS: Both MBS and GLP-1 RAs provide substantial metabolic benefits. MBS remains superior, but tirzepatide is a promising nonsurgical option supporting personalized obesity care.
Authors
Sabatella, Lucas; Ortega, Patricia M; Azcárate, Víctor Valentí; Sastre, Fernando Rotellar; Pagola, Adriana Uriz; Ahmed, Ahmed; Purkayastha, Sanjay; Ojanguren, Carlota Tuero; Asensio, Nuria Blanco; Landecho, Manuel F