RESUMEN
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a global health challenge, with a rising rate in line with other metabolic diseases. We aimed to assess the global prevalence of NAFLD in adult and pediatric populations. METHODS: PubMed, Scopus and Web of Science databases were systematically searched up to May 2023. Heterogeneity was assessed using Cochran's Q test and I2 statistics, and random-effects model was used for meta-analysis. Analyses were performed using STATA version 18. RESULTS: A total of 479 studies with 78,001,755 participants from 38 countries were finally included. The global prevalence of NAFLD was estimated to be 30.2% (95% CI: 28.7-31.7%). Regionally, the prevalence of NAFLD was as follows: Asia 30.9% (95% CI: 29.2-32.6%), Australia 16.1% (95% CI: 9.0-24.8%), Europe 30.2% (95% CI: 25.6-35.0%), North America 29% (95% CI: 25.8-32.3%), and South America 34% (95% CI: 16.9-53.5%). Countries with a higher human development index (HDI) had significantly lower prevalence of NAFLD (coefficient = -0.523, p = 0.005). Globally, the prevalence of NAFLD in men and women was 36.6% (95% CI: 34.7-38.4%) and 25.5% (95% CI: 23.9-27.1%), respectively. The prevalence of NAFLD in adults, adults with obesity, children, and children with obesity was 30.2% (95% CI: 28.8-31.7%), 57.5% (95% CI: 43.6-70.9%), 14.3% (95% CI: 10.3-18.8%), and 38.0% (95% CI: 31.5-44.7%), respectively. CONCLUSION: The prevalence of NAFLD is remarkably high, particularly in countries with lower HDI. This substantial prevalence in both adults and children underscores the need for disease management protocols to reduce the burden.