Islamic fasting and weight loss: a systematic review and meta-analysis

Abstract

Objective: Studies on the effects of Ramadan fasting on weight changes have been contradictory. We brought together all published data to comprehensively examine the effects in a systematic review and meta-analysis. Design: Relevant studies were obtained through searches of PubMed and CINAHL and by independent screening of reference lists and citations without any time restriction. All searches were completed between October and November 2011. Setting: Changes in body weight during and after Ramadan were extracted from thirty-five English-language studies and were meta-analysed. Most of the studies were conducted in West Asia (n 19); the remainder were conducted in Africa (n 7), East Asia (n 3) and North America/Europe (n 4). Subjects: Healthy adults. Results: Fasting during Ramadan resulted in significant weight loss (21?24 kg; 95 % CI 21?60, 20?88 kg). However, most of the weight lost was regained within a few weeks and only a slight decrease in body weight was observed in the following weeks after Ramadan compared with that at the beginning of Ramadan. Weight loss at the end of Ramadan was significant in both genders (21?51 kg for men and 20?92 kg for women); but again the weight loss lasted no longer than 2 weeks after Ramadan. Weight loss during Ramadan was greater among Asian populations compared with Africans and Europeans. Conclusions: Weight changes during Ramadan were relatively small and mostly reversed after Ramadan, gradually returning to pre-Ramadan status. Ramadan provides an opportunity to lose weight, but structured and consistent lifestyle modifications are necessary to achieve lasting weight loss.

Intermittent Fasting and Human Metabolic Health

“…Across these studies, participant age ranged from 18 to 58; just over half (52%) were conducted in males and females, 34% were in males only and 11% were in females only. 26 The authors of this review found statistically significant weight loss in 21 (62%) of these studies. 26 When pooled, the studies in this meta-analysis showed a 1.24 kg weight reduction (95% CI −1.60, −0.88 kg) over the month of Ramadan fasting.…”

“…26 The authors of this review found statistically significant weight loss in 21 (62%) of these studies. 26 When pooled, the studies in this meta-analysis showed a 1.24 kg weight reduction (95% CI −1.60, −0.88 kg) over the month of Ramadan fasting. Across 16 follow-up studies, mean weight regain was 0.72 kg (95% CI 0.32, 1.13 kg) in the 2 weeks following Ramadan.…”

Effects of intermittent fasting on glucose and lipid metabolism

“…One major difference between human and rodent studies is that human subjects tend to behaviourally reduce food intake during TRF when permitted ad libitum/ self-selected intake (51,54) . Similarly, many Ramadan studies report a mild energy deficit, although this is not a universal finding (55,57) . Where energy restriction is absent, or minimal, current evidence suggests that TRF can influence metabolism (both positively and negatively), necessitating further study into the optimal fasting window (52,53) .…”

Metabolic Effects of Intermittent Fasting

“…Across these studies, participants' ages ranged from 18 to 58 years; just more than half (52%) of studies were conducted with both males and females, 34% were conducted with only males, and 11% were conducted with only females (86). The authors of the review found statistically significant weight loss in 21 (60%) of the studies (86). When pooled, the studies in this meta-analysis showed a 1.24 kg weight reduction [95% confidence interval (CI), −1.60 to −0.88 kg] during the month of Ramadan fasting.…”