Beyond Weight Loss: Body Composition and Hydration Changes During Ramadan Fasting Among Apparently Healthy Young Adults

Introduction: Ramadan fasting involves prolonged daily abstinence from food and water with changes in meal timing, physical activity, and hydration.This study evaluated changes in body composition and hydration status during Ramadan fasting in apparently healthy young adults from Western Uttar Pradesh, a state in India.Methods: This prospective observational study commenced after Institutional Ethics Committee approval.Apparently healthy adults, aged 18-45 years, observing Ramadan fasting were recruited.Body weight (BW), body mass index (BMI), waist-hip ratio (WHR), skeletal muscle mass (SMM), body fat, visceral fat, and fluid compartments, including intracellular water (ICW) and extracellular water (ECW), as well as the ECW/total body water (TBW) ratio and resting metabolic rate (RMR) were assessed using bioelectrical impedance analysis before and within one week of completion of Ramadan fasting.Pre-and post-Ramadan values were compared using paired statistical tests.Results: The mean age of the participants was 26.6±8.5 years, with 26 (72.2%) males, and the mean fasting duration was 27.8±1.1 days.The BW, BMI, SMM, and RMR decreased significantly (p<0.001),whereas body fat mass, percentage body fat, visceral fat, and WHR showed no significant changes.There was a significant fall in ICW and ECW without any change in ECW/TBW.Conclusion: Ramadan fasting was associated with modest but significant reductions in body weight and BMI, accompanied by loss of SMM and body water rather than reduction in fat mass.The decline in RMR suggests metabolic adaptation during fasting.These findings highlight the importance of adequate hydration, nutrition, and physical activity during Ramadan to help preserve lean mass and support healthy fasting practices.