Global Childhood Obesity and Metabolic Syndrome: Prevalence, Risk Factors, and Meta-Analytic Evidence

Abstract

Background: Childhood obesity and metabolic syndrome are fast becoming major health challenges worldwide, although the estimates of prevalence rates vary largely due to the varying definitions, populations, and methodologies. Synthesizing contemporary evidence is essential for understanding the true magnitude and epidemiological pattern of these conditions. Aim and Objective: The objective was to answer the research question: "What is the pooled prevalence of childhood obesity and metabolic syndrome globally between 2021 and 2025, and what epidemiological patterns, risk factors, and clinical implications emerge from the recent evidence?" Methods: A systematic search of PubMed, Scopus, Embase, and Web of Science was conducted from 2021 to 2025 using predefined keywords. Ten studies entered qualitative synthesis, while five with extractable proportions entered meta-analysis. Data extraction was performed using Microsoft Excel (version 16), while statistical analyses were carried out in RStudio, including random-effects pooling, funnel plot asymmetry tests, and linear regression. Quality assessment was done using the AMSTAR-2, NOS, and JBI tools. Results: The pooled prevalence from five studies was 9.2% (95% CI 7.1–11.3) with extreme heterogeneity (I² ≈ 99.99%, p < 0.001). Funnel plot asymmetry tests, including Egger's test (p > 0.05), indicated no significant publication bias. Epidemiological patterns from the studies showed rising obesity trends and a MetS prevalence of 3–5%, consistent with associations to lifestyle-linked risk factors. Conclusion: Childhood obesity is still a significant and growing global burden, while MetS affects a smaller but clinically important subset. Heterogeneity emphasizes the need for standardized definitions and stratified risk assessment. Integrated preventive strategies and enhanced surveillance systems are urgently needed.