Intermittent fasting versus continuous energy restriction in MASLD: a systematic review and meta-analysis.

BACKGROUND

Intermittent fasting (IF) and continuous energy restriction (CER) are widely used dietary approaches for metabolic dysfunction-associated steatotic liver disease (MASLD), yet their comparative efficacy remains uncertain.

METHODS

PubMed, Embase, Web of Science, and Cochrane Central were searched from inception to August 1, 2025, for randomized controlled trials comparing intermittent fasting (IF) with continuous energy restriction (CER) in adults with NAFLD, MAFLD, or MASLD. Risk of bias was assessed using RoB 2, and weighted mean differences were pooled using random-effects models.

RESULTS

Nine trials (n = 894) were included, involving time-restricted feeding (TRF), alternate-day fasting (ADF), and 5:2 fasting (whole-day fasting, WDF). Compared with CER, IF was associated with greater reductions in body weight (MD = -1.29 kg; 95% CI, -1.98 to -0.61), BMI (MD = -0.34 kg/m2; 95% CI, -0.55 to -0.13), LDL-C (MD = -0.08 mmol/L; 95% CI, -0.15 to -0.01), and controlled attenuation parameter (CAP) (MD = -15.13 dB/m; 95% CI, -28.87 to -1.39). No significant between-group differences were observed for magnetic resonance imaging-proton density fat fraction (MRI-PDFF), liver stiffness, transaminases, glucose-related indices, total cholesterol, triglycerides, or HDL-C. In subgroup analyses, WDF was associated with a greater reduction in CAP, whereas TRF appeared to be associated with greater reductions in body weight and BMI.

CONCLUSION

In patients with MASLD, intermittent fasting was associated with greater reductions in body weight, BMI, and LDL-C than continuous energy restriction. Although CAP-based analyses suggested a possible advantage of intermittent fasting for hepatic steatosis, this finding was not confirmed by MRI-PDFF and was no longer statistically significant in sensitivity analyses. Further large-scale, long-term randomized trials are needed to confirm these findings.

SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251149184, Identifier: CRD420251149184.