BMJ

Are all types of intermittent fasting created equal?

July 4, 2025

Study details: This systematic review and network meta-analysis (NCT05309057) evaluated 99 randomized clinical trials involving 6,582 adults (mostly with existing health conditions) to compare the effects of intermittent fasting (alternate day fasting, time-restricted eating, whole-day fasting), continuous energy restriction, and ad-libitum diets on body weight and cardiometabolic risk factors.

Results: All intermittent fasting and continuous energy restriction strategies significantly reduced body weight compared with ad-libitum diets. Notably, alternate day fasting led to greater weight loss than continuous energy restriction (mean difference −1.29 kg; 95% confidence interval [CI] −1.99 to −0.59; moderate certainty of evidence). It also improved waist circumference, lipid profiles, and inflammatory markers.

Clinical impact: Alternate day fasting may offer a more effective dietary strategy for weight loss and cardiometabolic risk reduction than traditional calorie restriction. However, long-term adherence and safety remain to be fully established, underscoring the need for individualized dietary counseling.

Source:

Semnani-Azad Z, et al. (2025, June 18). BMJ. Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials. https://pubmed.ncbi.nlm.nih.gov/40533200/