S2783 Lifestyle Modification in Early Non-Alcoholic Fatty Liver Disease: A Meta-Analysis and Subgroup Comparison of Exercise and Diet Interventions

Introduction: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally and a growing public health burden. In the absence of approved pharmacologic therapies, structured lifestyle interventions are the cornerstone of management. This meta-analysis evaluates the effectiveness of physical exercise and dietary modification in reversing key clinical and biochemical markers of early-stage NAFLD, with a subgroup analysis comparing their differential impacts. Methods: A systematic search of PubMed, ScienceDirect, Cochrane Library, ClinicalTrials.gov, Google Scholar, and PLOS ONE was conducted. Fourteen randomized controlled trials (RCTs) involving adult patients with NAFLD were included. Interventions consisted of either structured physical exercise or a controlled diet, compared to usual care. Primary outcomes included liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT]), insulin resistance (HOMA-IR), and body mass index (BMI). Results were pooled using mean differences (MD) with 95% confidence intervals (CI). Subgroup analysis was performed to evaluate biomarker-specific effects by intervention type. Results: Exercise Subgroup: Significantly reduced AST (MD: -4.48; CI: -4.82 to -4.14), ALT (MD: -5.43; CI: -5.91 to -4.94), HOMA-IR (MD: -0.29; CI: -0.35 to -0.23), and BMI (MD: -0.66; CI: -0.74 to -0.58). Diet Subgroup: Reduced AST (MD: -4.28; CI: -5.09 to -3.48), ALT (MD: -5.04; CI: -5.91 to -4.16), and BMI (MD: -0.76; CI: -0.81 to -0.70), but did not significantly affect HOMA-IR (MD: -0.08; CI: -0.17 to 0.01). Both interventions improved overall quality of life and physical fitness. Exercise uniquely improved insulin resistance, while both interventions demonstrated comparable benefits in liver enzymes and BMI. These findings suggest distinct metabolic advantages of exercise in NAFLD reversal. Conclusion: Structured exercise and dietary interventions significantly improve metabolic and hepatic outcomes in early NAFLD. Exercise appears to offer broader benefits, particularly in insulin sensitivity, supporting its prioritization in personalized lifestyle protocols. These findings may inform updated NAFLD guidelines and support integration of structured exercise into first-line management.