Does Ramadan fasting affect sleep

Experimental fasting has been shown to alter the sleep-wakefulness pattern in various species. As fasting during Ramadan is distinct from experimental fasting, the physio-logical and behavioural changes occurring during Ramadan fasting may differ from those occurring during experimen-tal 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 associ-ate 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 sleepi-ness and function and sleep architecture during the month of Ramadan. Where applicable, these findings are com-pared with those obtained during experimental fasting