Global ecological associations between overweight/obesity and non-communicable disease prevalence among children aged 5-9 years: a sex-stratified analysis of 174 countries.

INTRODUCTION: Childhood overweight and obesity are increasing worldwide, yet their population-level associations with a broad range of non-communicable diseases (NCDs) among children aged 5-9 years remain insufficiently characterized. This study examined the country-level associations between overweight/obesity and NCDs prevalence and explored whether these association patterns differed by sex. METHODS: This ecological study included 2022 national-level data from 174 countries. The prevalence of NCDs among children aged 5-9 years was obtained from the Global Burden of Disease (GBD), while overweight and obesity prevalence estimates were obtained from the World Health Organization Global Health Observatory (GHO). We utilized Spearman's correlation analysis to assess correlations and Random Forest to explore predictive importance, while generating forest plots and importance summary plots as independent visualization tools for the results. RESULTS: Significant global disparities in childhood overweight/obesity existed, with high prevalence in the Americas/Europe and low in Africa/Southeast Asia. Both were significantly positively correlated with multiple NCDs (p < 0.05). For overweight and obesity, the strongest correlations were with neoplastic disease, digestive and urinary system disease, neurological and psychiatric disease, as well as cardiovascular disease. After Benjamini-Hochberg false discovery rate (FDR) correction, multiple positive associations remained significant in the overall and boys' analyses, including associations with skin-related diseases among boys, whereas no positive associations remained significant among girls. CONCLUSION: This study provides epidemiological evidence on robust positive associations between childhood overweight/obesity and a broad spectrum of NCDs. Governments and global health systems should implement preventive measures against childhood weight abnormalities.