Exercise, Dietary, and Combined Exercise-Dietary Interventions for Metabolic Syndrome: A Bayesian Network and...

Existing reviews have not clarified how exercise only, dietary only, and combined exercise dietary interventions compare across individual metabolic syndrome (MetS) components. We aimed to compare structured exercise-only, dietary-only, and combined exercise-dietary interventions in adults with MetS and overweight or obesity with an inactive or minimal-intervention control or other active interventions for waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), triglycerides (TG), and high-density lipoprotein cholesterol. We also assessed whether the combined effects were compatible with the sum of their component effects. We searched PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Scopus from inception to December 2025 for randomized controlled trials. Comparative effects were estimated using Bayesian random-effects network meta-analysis; a frequentist component network meta-analysis was used to assess additivity, and certainty was assessed using the Confidence in Network Meta-Analysis framework. Seventy-eight trials with 8,452 participants were included. Relative to the control node, all four structured exercise-only interventions were associated with lower SBP and DBP, and resistance training was associated with lower FBG. Among nodes representing combined exercise-dietary interventions, combined exercise plus Mediterranean diet, moderate-intensity continuous training (MICT) plus caloric restriction, and MICT plus a low-carbohydrate diet were associated with lower WC, TG, and FBG, respectively, relative to the control node. For WC and TG, the results were consistent with a simple model that adds the estimated effects of exercise and diet, this model did not fit the other four outcomes. Certainty was low to very low for most comparisons. As a Bayesian synthesis, the findings do not identify a preferred intervention, but indicate which exercise, dietary and combined approaches warrant testing in adequately powered direct comparative trials. REGISTRY: This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD420251134142).