oa Negative Influence of Intermittent Ramadan Fasting and Unhealthy Lifestyle on Body Composition, Sleep, Physical Fitness and Iron Indices in School Boys

Background: Schoolchildren must practice healthy diet as well as active lifestyle to support their physical growth and development. Previous studies have shown that intermittent fasting can affect dietary intake, sleep duration and circadian patterns among adults, but there is a lack of related literature in schoolchildren.

Purpose: The aim of this study was to objectively assess the effect of Ramadan fasting on physiological parameters in young children.

Methods: Eighteen boys aged 12.6±1.5 years were assessed at baseline (BR) and followed up twice during Ramadan (1st week [R1], 4th week [R4]) and once two weeks after the end of Ramadan (AR). Body composition was assessed using anthropometry and DXA scan. Blood investigations included complete blood count, lipid profile analysis and iron indices. Pattern of daily activity and core body temperature were recorded using a triaxial accelerometer and ingestible thermistor pill, respectively. Dietary intake was assessed by experienced nutritionist based on digital images of food and drinks consumed by each participant during a 24-hour period. Repeated sprints tests (RSA) of 6 × 15 m sprints interspaced by 15 s rest were performed to evaluate fatigue resistance.

Results: There was a shift in daily peak activity from daytime (5:30 PM) to late night (12:00 AM) that resulted in 1.8±0.6 hours of loss in total sleep time during R4 (P<0.01). After 30 days of fasting there were no important change in lipids, but a significant drop in serum iron from 17.7±1.6 μmol/L at BR to 13.1±1.4 μmol/L (P<0.01), suggesting a potential nutritional deficiency. Moreover, reduction in serum iron was associated with younger age (r=0.47, P=0.05) and lighter body weight (r=0.37, P=0.13). Dietary analysis showed that subjects consumed a high calorific diet deficient in fruits and vegetables during Ramadan that explains weight gain (+1.0±0.2 kg, P=0.001) and consequently longer sprint times on RSA test (+0.4±0.1 s, P=0.04) at R4 compared to baseline.

Conclusion: This study concludes that intermittent Ramadan fasting may have an undesirable impact on body composition, sleep patterns and nutritional habits in young schoolchildren. These results could be used to develop educational strategies to promote a healthy lifestyle in schoolchildren during Ramadan.