Dietary Intake and Body Composition During Ramadan in Athletes: A Systematic Review and Meta-Analysis With Meta-Regression

The aim of this research was to evaluate the effect of Ramadan observance on dietary intake and body composition in adult athletes. This was a systematic review and meta-analysis. Data sources used were PubMed, Web of Science, Scopus, and Taylor and Francis. Eligibility criteria for selecting studies were as follows: single-group, pre-/post-Ramadan, with or without control group, conducted in athletes aged >= 19 years training at least twice a week, and published in any language before August 25, 2021. Studies assessing dietary intake and/or body composition were deemed eligible. The methodological quality of studies was assessed using QualSyst. Nine studies evaluated dietary intake; 4 of these were rated as strong quality and the remaining as moderate. Of the 17 selected studies evaluating body composition, 7 were of strong quality and the remaining 10 were rated as moderate. Compared to pre-Ramadan, energy (number of studies, K = 7; number of participants, N = 78; g =-0.781; 95% confidence interval [CI],-1.416 to-0.145; p = 0.016), carbohydrate (K = 5; N = 50; g =-1.643; 95% CI,-2.949 to-0.336; p = 0.014), and water (K = 4; N = 39; g =-1.081; 95% CI,-1.371 to-0.790; p = 0.000) intakes decreased during Ramadan. However, fat (K = 5; N = 50; g =-0.472; 95% CI,-1.085 to 0.140; p = 0.131) and protein (K = 5; N = 60; g =-0.574; 95% CI,-1.213 to-0.066; p = 0.079) intakes remained unchanged. Compared to pre-Ramadan, body mass (K = 16; N = 131; g =-0.262; 95% CI,-0.427 to-0.097; p = 0.002) and body fat percentage (K = 8; N = 81; g =-0.197; 95% CI,-0.355 to-0.040; p = 0.014) decreased in the fourth week of Ramadan. Lean body mass did not change during Ramadan (K = 4; N = 45; g =-0.047; 95% CI,-0.257 to 0.162; p = 0.658). Carbohydrate and total water intake decreased with the observance of Ramadan, but fat and protein intake were unchanged. Continued training of athletes during Ramadan was associated with a decreased body mass and body fat percentage, but not lean body mass, toward the end of the fasting month.

Automated summary

This research aimed to evaluate the impact of Ramadan observance on dietary intake and body composition in adult athletes. It was a systematic review and meta-analysis that included nine studies on dietary intake and seventeen studies on body composition. The findings showed a decrease in energy, carbohydrate, and water intake during Ramadan, while fat and protein intake remained unchanged. Body mass and body fat percentage decreased in the fourth week of Ramadan, but lean body mass did not change. Continued training during Ramadan was associated with decreased body mass and body fat percentage towards the end of the fasting month.