Changes in energy and macronutrient intakes during Ramadan fasting: a systematic review, meta-analysis, and meta-regression.

This article systematically reviews and meta-analyzes the effects of Ramadan fasting (RF)—a diurnal intermittent fasting observed by Muslims—on dietary energy and macronutrient intakes, including carbohydrates, protein, fats, dietary fiber, and water. Analyzing data from 85 studies with 4,594 participants across 22 countries, the meta-analysis found statistically significant but modest reductions in total caloric intake (−142.45 kcal/day), carbohydrates (−23.90 g/day), protein (−4.21 g/day), and water (−350.80 mL/day) during Ramadan compared to pre-fasting levels, while fat and fiber intakes showed no significant changes. The study highlights that these small quantitative dietary changes are unlikely to fully explain the physiological and metabolic effects of RF, suggesting that alterations in meal timing rather than dietary composition are the primary drivers of observed health outcomes. Moderator analyses indicated that age significantly influenced dietary changes, and physical activity moderated water intake, but sex, fasting duration, and health status did not significantly affect macronutrient intake changes.