Effects of intermittent fasting regimens on glycemic, hepatic, anthropometric, and clinical markers in patients with non-alcoholic fatty liver disease: Systematic review and meta-analysis of randomized controlled trials

Objectives: Intermittent fasting (IF) regimens have been hypothesized to influence several markers of cardiometabolic and liver function. The objective of our meta-analysis was to investigate the impact of IF regimens on cardiometabolic and liver markers in subjects diagnosed with non-alcoholic fatty liver disease (NAFLD). Methods: We searched several online databases (PubMed/Medline, Web of Science, Scopus and Embase) in order to identify suitable publications for inclusion in the meta-analysis. Results were expressed as weighted mean differences (WMD).Results: From 12343 articles identified in different databases, a total of 7 RCT arms were entered into the quantitative synthesis. The manuscripts were published between 2019 and 2023. IF regimens (the 5:2 diet, 16/8 time-restricting feeding, and alternate day fasting) varied from 2 months to 3 months. IF regimens reduced steatosis scores (WMD:-33.22 CAP dB/m, 95 % CI:-50.72 to-15.72), anthropometric characteristics of obesity (WMD:-0.77 kg/m2, 95 % CI:-1.38 to-0.17 for body mass index; WMD:-3.16 kg, 95 % CI:-4.71 to-1.61 for body weight; WMD:-1.90 kg, 95 % CI:-3.51 to-0.29 for waist circumference), as well as ALT (WMD:-9.10 U/L, 95 % CI:-12.45 to-5.75), triglyceride (WMD:-20.83 mg/dl, 95 % CI:-39.01 to-2.66), total cholesterol (WMD:-7.80 mg/dl, 95 % CI:-15.18), HbA1c (WMD:-0.14 %, 95 % CI:-0.20 to-0.08) and HOMA-IR (WMD:-1.21, 95 % CI:-2.08 to-0.34) levels versus controls. Nevertheless, no between-group differences were detected for other biomarkers, e.g., fasting blood glucose, insulin, AST, HDL-C or LDL-C values, and fibrosis scores.Conclusion: IF regimens can improve some markers of cardiometabolic and liver function in patients with NAFLD. However, the available evidence to support the benefits of IF regimens is limited and