The Global Prevalence of Metabolic Syndrome in Adults and Its Association With Lifestyle Factors: A Systematic Review and Meta-Analysis

Metabolic syndrome (MetS) is a cluster of cardiometabolic risk factors that poses a significant and growing global public health challenge. Lifestyle behaviors play a central role in its development; however, a comprehensive quantitative synthesis of global prevalence and associated lifestyle factors remains limited. This systematic review and meta-analysis aimed to estimate the pooled global prevalence of MetS in adults and examine its association with key modifiable lifestyle behaviors. Five electronic databases were systematically searched for observational studies published between 2015 and 2025 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were pooled using a random-effects meta-analysis. Prevalence estimates were calculated with 95% confidence intervals (CIs), and associations between lifestyle factors and MetS were synthesized using pooled effect sizes (odds ratios [ORs] and standardized mean differences where applicable). Heterogeneity was assessed using the I² statistic, and subgroup analyses were conducted to explore potential moderators. Ten observational studies comprising 54,709 participants were included. The pooled global prevalence of MetS was 32% (95% CI: 22%-43%), although heterogeneity was substantial (I² = 98.72%). Physical inactivity was consistently associated with increased odds of MetS (representative OR range across studies: 1.25-2.15), while adherence to recommended physical activity levels was protective (e.g., OR 0.64; 95% CI 0.42-0.98). Poor diet quality, smoking, short and long sleep duration, and alcohol consumption were also associated with higher MetS risk. Subgroup analyses by diagnostic criteria, geographic region, gender distribution, and mean age did not significantly explain between-study heterogeneity. Although adverse lifestyle behaviors are consistently linked to increased MetS risk across adult populations, the magnitude of association varies considerably due to substantial unexplained heterogeneity and possible publication bias. These findings support lifestyle modification as a key preventive strategy while highlighting the need for cautious interpretation of pooled estimates.