The Dietary Pattern Concerning Non-alcoholic Fatty Liver: An Umbrella Review and Meta-analyses of Observational Studies and Intervention Trials

Context: Non-alcoholic fatty liver disease (NAFLD) has been extensively studied in recent years, but the optimal dietary patterns for improving this condition remain unclear. Evidence Acquisition: Therefore, this umbrella review aimed to summarize the available evidence from meta-analyses on the relationship between various dietary patterns and NAFLD. Results: Two independent researchers identified published meta-analyses of interventional and observational studies that investigated the relationship between dietary patterns and NAFLD by searching electronic databases up until March 2023 and extracting relevant information. The pooled effect size of dietary patterns on NAFLD was evaluated using the standard mean difference (SMD) with a 95% confidence interval (CI). Fourteen meta-analyses met the inclusion criteria. Conclusions: All NAFLD-related outcomes, including hepatic steatosis, Fatty Liver Index (FLI), liver stiffness, and liver enzymes, were significantly affected by a calorie-restricted diet. Similarly, following the Mediterranean diet had beneficial effects on improving these outcomes. The findings support the role of a calorie-restricted diet and a Mediterranean diet in improving NAFLD, alongside the treatment protocol for these patients.