The effect of Ramadan fasting on anthropometric and body composition of healthy adults within different time points: A systematic review and meta-analysis.

To date, the effect of Ramadan fasting (RF) on anthropometric and body compositions remains inconsistent. This review aimed to investigate the impact of RF on anthropometric and body composition of healthy adults within different time points during and after RF. Qualified studies from MEDLINE, Web of Science, Embase, CINAHL Complete, ProQuest, and Scopus were included. We involved prospective observational studies with pre- and post-test design. The anthropometric and body composition parameters consist of weight, BMI, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), absolute fat mass (FM), fat percentage (FP), fat-free mass (FFM), and total body water (TBW). Fifty-four studies involving 2857 subjects were identified and conducted in 21 countries between 1987 and 2024. RF exerts a significant reduction in weight and BMI, starting within the second and third week of RF, peaking in the first week after RF, and gradually returning to the pre-Ramadan value in the weeks afterward. Meanwhile, WC, HC, and WHR were significantly alleviated within the last week of RF and the first week post-RF for HC. In body composition, RF elicits a significant but small reduction of absolute FM and FP within the third and fourth week of RF, while FFM and TBW were not affected. During Ramadan, anthropometric and body composition changes are transient and elicit only a short-term effect. Such leverages need to be maintained to achieve a long-term benefit of RF on the anthropometric and body composition of healthy adults.