Hepatic and metabolic changes during Ramadan diurnal intermittent fasting in adults with MASLD and elevated ALT: a prospective multicenter study

Abstract

Abstract Background Ramadan diurnal intermittent fasting (RDIF) is one of the most widely practiced religious fasting traditions worldwide and represents a culturally embedded model of dry, time-restricted fasting. Its hepatic, metabolic, and behavioral effects in metabolic dysfunction–associated steatotic liver disease (MASLD) remain incompletely characterized. Methods In this multicenter prospective observational pre–post study, adults aged 18–65 years with MASLD and elevated alanine aminotransferase (ALT; >1.5× the upper limit of normal) were recruited from eight tertiary centers in Saudi Arabia and Egypt during Ramadan 2024. Participants underwent assessments within 7 days before Ramadan and during the final week of Ramadan, including anthropometry, liver biochemistry, lipid and glycemic profiles, vibration-controlled transient elastography (VCTE) with controlled attenuation parameter (CAP), dietary intake, and physical activity (PA). Analyses evaluated paired within-participant changes among participants who completed at least 21 consecutive fasting days. Results Among 80 participants (median age 46.1 years; 61.2% male; median body mass index 31.9 kg/m²), RDIF was associated with significant reductions in body weight (90.0 to 89.5 kg), waist circumference (103.1 to 97.0 cm), ALT (95.3 to 70.0 U/L), aspartate aminotransferase (AST; 55.5 to 46.3 U/L), and CAP (317.0 to 280.5 dB/m), all p < 0.05. Reductions in ALT, AST, and CAP remained significant after multivariable adjustment. In ALT responder analyses, 70.0% of participants achieved a reduction of ≥ 20%, and 17.5% achieved ALT normalization. Liver stiffness measurements did not change significantly. Significant reductions were also observed in total cholesterol (5.1 to 4.9 mmol/L), triglycerides (1.8 to 1.7 mmol/L), and low-density lipoprotein cholesterol (2.9 to 2.8 mmol/L). PA declined significantly, and exploratory analyses did not identify consistent associations between behavioral changes and hepatic improvements. Conclusions In adults with MASLD and elevated ALT, RDIF was associated with short-term improvements in CAP, liver injury markers, and cardiometabolic parameters despite reduced PA and no consistent evidence of caloric restriction. These findings support further controlled studies evaluating RDIF as a culturally embedded form of time-restricted eating in MASLD. Registration Not applicable (prospective observational study not registered as a clinical trial).