Threshold Effects of Dietary Components on Global NAFLD Burden: Modulating Role of Socioeconomic Development

Non-alcoholic fatty liver disease (NAFLD) affects approximately 25% of the adult population worldwide. This study quantifies the global NAFLD burden attributable to 10 dietary components across diverse populations.

This study integrated 2018 data from the Global Dietary Database (GDD) and the Global Burden of Disease (GBD) study to analyze correlations of dietary nutrients with the incidence and prevalence of NAFLD across 185 countries. Nonlinear relationships were explored using generalized additive models (GAM), with findings subsequently validated against National Health and Nutrition Examination Survey (NHANES) data. Additionally, Spearman correlation analysis was performed to assess associations between sociodemographic development (SDI) and dietary intake patterns.

South Asia and sub-Saharan Africa have high carbohydrate but low protein and fat intake; North America and Western Europe display a "Western diet," showing regional nutritional differences. Nutrient intake varies by age, gender, and region, especially for carbohydrates, protein, fat, and Omega-3 s. In 2018, NAFLD burden was highest in the Middle East and North Africa. Higher SDI linked to increased animal protein and cholesterol intake, and greater NAFLD risk. GAM analysis revealed complex nonlinear nutrient-NAFLD relationships: carbohydrate intake had peak NAFLD risk at intermediate levels (p < 0.01); dietary cholesterol showed dose-dependent risk plateauing at higher intakes (p < 0.001). Protein intake correlated positively with disease burden. Most nutrient-NAFLD associations in NHANES data supported global findings.

This study uses a global database to analyze 10 nutrients' relation to NAFLD, showing nonlinear effects and regional differences. It suggests focusing on nutrient-specific interventions over broad dietary patterns.