Does Ramadan fasting affect sleep?


Dr Ahmed BaHammam, Associate Professor, Director Sleep Disorders Center, College of Medicine, Department of Medicine 38, King Saud University, PO Box 2925, Riyadh 11461, Saudi Arabia
Tel.: + 966 1 467 1521
Fax: + 966 1 467 2558


Experimental fasting has been shown to alter the sleep-wakefulness pattern in various species. As fasting during Ramadan is distinct from experimental fasting, the physiological and behavioural changes occurring during Ramadan fasting may differ from those occurring during experimental fasting. There has been increased interest in recent years in sleep changes and daytime sleepiness during Ramadan. Moreover, many of those who fast during Ramadan associate this fasting with increased daytime sleepiness and decreased performance. This raises the question of whether Ramadan fasting affects sleep. In this review, we discuss the findings of research conducted to assess changes in sleep pattern, chronobiology, circadian rhythms, daytime sleepiness and function and sleep architecture during the month of Ramadan. Where applicable, these findings are compared with those obtained during experimental fasting.