The effect of intermittent fasting during Ramadan on sleep, sleepiness, cognitive function, and circadian rhythm

Abstract

Studies that controlled for environmental factors and sleep/wake schedule reported no significant disturbances in sleep architecture. Nevertheless, several studies have consistently reported that the main change in sleep architecture during fasting is a reduction in the proportion of REM sleep.

Increase in Ischemic Stroke Incident Hospitalizations Among Bedouin Arabs During Ramadan Month

“…1 A month of daily fasting from fajr (dawn), until the maghrib (dusk) is an obligatory practice during the holy month of Ramadan 2 as well as refraining from sexual activity, smoking, and getting angry. 3 Several physiological changes such as changes in circadian rhythm, 4 serum lipid and glucose levels 5 as well as renal function markers and hematocrit levels, 6 have been reported among observant Muslims during Ramadan. In addition, Ramadan has been associated with exacerbation of several medical conditions such as diabetes mellitus, migraines, and chronic kidney disease.…”

Recent Evidence on the Impact of Ramadan Diurnal Intermittent Fasting, Mealtime, and Circadian Rhythm on Cardiometabolic Risk: A Review

“…IF means abstinence of food and drink in specified time periods. IF can be practiced in different forms, such as abstinence from food every other day (36), significant reduction in caloric consumption every other day (37), moderate caloric restriction for 2 consecutive days/week (38), restricting of food to specific times of a 24-r period, which is called TRF (21), abstinence from food for 1 or 2 days per week and then ad libitum food consumption for the rest of the week, as well as the diurnal IF performed by Muslims during the month of Ramadan where fasting performers abstain from food as well as drinks from dawn to sunset for the whole month (29-30 days) (39).…”

“…Nonetheless, it is imperative to mention here that all the above reviewed studies occurred in the free-living unconstrained environment and did not account for potential confounders that may have affected the measured parameters, such as caloric intake and food composition (54), sleep duration (55), physical activity (57), and energy expenditure (57), which have been shown to change in Ramadan (39).…”

The Effect of Ramadan Fasting on Metabolic Syndrome (MetS)

“…Furthermore, well-designed studies showed no effect of Ramadan fasting on circadian rhythms. However, in unstable society in which they do not control for lifestyle changes, evidences have demonstrated sudden and significant delays in bedtime and wake time [41]…”