Published Paper Details:

Abstract Background: Though their relative efficacy is still up for discussion, intermittent fasting (IF) and calorie restriction (CR) are two well-liked dietary strategies for managing weight. The present data are compiled in this meta-analysis to ascertain the relative effectiveness of IF versus CR for weight loss and cardiometabolic health outcomes. Methods: A comprehensive systematic review and meta-analysis were conducted following PRISMA guidelines. We searched PubMed, Embase, Web of Science, and Cochrane databases from inception through October 2025. Randomized controlled trials (RCTs) comparing IF (alternate day fasting, time-restricted eating, 5:2 diet) with CR or control diets in adults with overweight or obesity were included. The primary outcome was body weight change; secondary outcomes included body composition, metabolic markers, cardiovascular parameters, and inflammatory biomarkers. Effect sizes were calculated using random-effects models with 95% confidence intervals. Results: Ninety-nine RCTs involving 6,582 participants were included. Both IF and CR produced significant weight loss compared to ad-libitum diets. Alternate-day fasting demonstrated superior weight loss compared to CR (mean difference: -1.29 kg, 95% CI: -1.99 to -0.59, moderate certainty). IF combined with CR yielded greater weight reduction than CR alone (MD: -2.11 kg, 95% CI: -2.68 to -1.54, p<0.00001). IF showed preferential fat mass loss (MD: -1.08 kg, p=0.0001) while preserving lean mass. IF improved insulin resistance (HOMA-IR reduction: -0.32, 95% CI: -0.59 to -0.06, p=0.02) and glycemic control (HbA1c reduction: -0.9%, p<0.05) more effectively than CR. Both approaches similarly improved blood pressure and lipid profiles. Adherence rates were comparable between IF and CR (dropout rates: 0-65%, no significant difference). Common adverse events were transient and mild. Conclusions: Intermittent fasting, particularly alternate-day fasting and early time-restricted eating, demonstrates modest but significant advantages over traditional calorie restriction for weight loss and metabolic health outcomes. IF represents an evidence-based alternative dietary strategy, especially for individuals who find daily calorie restriction challenging. The choice between IF and CR should be individualized based on patient preferences, lifestyle factors, and metabolic goals.