Ketogenic Diet Effects on Liver Health in Metabolic Dysfunction–Associated Steatotic Liver Disease: A Systematic Review

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver condition and is linked to unhealthy lifestyle patterns. Dietary modification remains the cornerstone of management. Among available nutritional strategies, ketogenic diets (KDs) have gained increasing attention. This systematic review evaluated the impact of KD, versus no dietary intervention or control diets, on hepatic and metabolic outcomes in adults with MASLD. Following PRISMA guidelines, PubMed, Scopus and Web of Science were searched through June 2026. Two reviewers independently screened records, assessed eligibility and extracted data. Risk of bias was evaluated using CASP for randomized controlled trials (RCTs) and ROBINS-I for non-randomized studies. Meta-analysis was not feasible due to study heterogeneity. Fourteen studies were included: five RCTs and nine prospective cohorts, involving 776 adults with MASLD and/or hepatic steatosis. KD was associated with improvements in MASLD severity indices, anthropometric measures, lipid profile, glycaemic markers and liver enzymes. Among RCTs, liver fat decreased by -4.77% (PDFF) to a 77% (relative MRI-LFF), with reductions in body weight (up to -12.0 kg) and waist circumference (up to -9.6 cm). Prospective studies showed similar findings, including reductions in controlled attenuation parameter (up to -57 dB/m), intrahepatic triglyceride (-31%) and Fatty Liver Index (-14.03 points). Evidence regarding liver stiffness and fibrosis-related outcomes was more limited and less consistent. KD may improve disease severity, hepatic steatosis, anthropometric measures, glycaemic control, lipid metabolism and liver-related biochemical markers in adults with MASLD. However, methodological heterogeneity precludes outcomes assessment, and limited evidence on fibrosis-related evidence precludes firm conclusions. Larger, longer-standardized RCTs are needed to clarify KD's role in MASLD management.