Effects of Lifestyle and Glucagon-Like Peptide-1 Receptor Agonist-Based Therapies on Waist Circumference: A Systematic Review and Meta-Analysiskey Takeaway Messages

Background and aims: Central obesity, commonly assessed using waist circumference (WC), is strongly associated with cardiometabolic risk. While lifestyle interventions and glucagon-like peptide-1 receptor agonist-based therapies (GLP-1RA-based therapies) reduce body weight, their effects on WC and factors influencing response remain incompletely characterised. This systematic review and meta-analysis evaluated the effects of these interventions on WC in randomised controlled trials (RCTs). Methods: Following PRISMA 2020 guidelines, we searched PubMed for RCTs published between 2010 and 2025 that reported outcomes related to WC or visceral adipose tissue in adults. Eligible interventions included diet, exercise, diet plus exercise, and GLP-1RA-based therapies. Data from 27 intervention-comparator study arms (21 RCTs; n = 3196) were pooled using random-effects models to estimate between-group mean differences in WC change. Meta-regression explored associations between baseline characteristics and WC response. Publication bias was assessed using funnel plots and Egger's test. Results: Interventions were associated with significant reductions in WC (MD: −4.36 cm; 95% CI: −4.97 to −3.74; prediction interval: −6.98 to −1.73). Subgroup analyses demonstrated significant reductions for GLP-1RATs (MD -5.93 cm; 95% CI -7.88 to −3.98) and diet-alone interventions (MD -3.46 cm; 95% CI -5.91 to −1.00). Exercise-only and diet-plus-exercise interventions showed more variable effects, and subgroup differences were not statistically significant. Exploratory meta-regression suggested potential associations between baseline anthropometric measures, age, and WC reduction, although these findings should be interpreted cautiously. WC change was positively associated with visceral adipose tissue change at the study-arm level. Funnel plots suggested possible small-study effects (Egger's p = 0.0025). Conclusions: GLP-1RA-based therapies and dietary interventions were associated with reductions in WC in adults. WC may serve as a practical anthropometric marker of intervention response, although observed associations with visceral adipose tissue were derived from study-arm-level analyses. Further studies are needed to better define predictors of treatment response.