Effects of tai chi on obesity and metabolic health: a systematic review and meta-analysis of randomized controlled trials with a supplementary descriptive review of non-randomized studies

Background/Objectives: The global prevalence of obesity and metabolic syndrome has reached alarming levels, with over 650 million adults classified as obese in 2022 (WHO data). These conditions significantly elevate risks for cardiovascular diseases and type 2 diabetes mellitus, necessitating cost-effective lifestyle interventions. Despite evidence supporting the benefits of mind-body exercises, no prior meta-analysis has quantified the dual effect of Tai Chi on both anthropometric and metabolic biomarkers across diverse populations. We aimed to systematically evaluate the efficacy of Tai Chi versus active/passive controls on 1) primary outcomes (BMI, waist circumference) and 2) secondary outcomes (glycemic control, lipid profile, psychological health). Methods: We searched six databases (PubMed, Web of Science, Scopus, Cochrane, CNKI, PubScholar) from 2000 to December 2024 for randomized controlled trials (RCTs) and controlled clinical trials (CCTs). For quantitative synthesis, only RCTs were meta-analyzed; CCTs were reviewed descriptively. Data were extracted by two independent reviewers. The Cochrane RoB 2.0 tool assessed bias. Pooled mean differences (MDs) or standardized mean differences (SMDs) with 95% CIs were calculated using random-effects models. Publication bias was assessed via Egger’s test and funnel plots. Results: A total of 277 records were identified. After screening, 17 RCTs were included in the meta-analysis. Analysis of these 17 RCTs demonstrated significant reductions... An additional 5 non-randomized controlled trials were reviewed descriptively but not pooled. BMI (SMD = -1.20, 95% CI [-1.85, -0.55], I² = 76.5%), waist circumference (-6. 15 cm [-9.41, -2.90]), and fasting glucose (-0.21 mg/dl [-0.42, -0.00]). Meta-regression revealed that intervention duration was a key moderator (β = -0.01, p = 0.01). Secondary outcomes showed reduced anxiety (-0.59 [-0.97, -0.22]) and depression (-0.44 [-0.78,-0. 10]), but no significant effects on body weight (p=0.08), blood pressure, or lipids. High heterogeneity (I²=94.8% for weight) was attributed to variable intervention protocols. Conclusions: This study represents the first meta-analysis to combine anthropometric measurements, body composition, and metabolic outcomes, providing evidence that Tai Chi significantly reduces central adiposity and improves glycemic control.