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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.
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Does Ramadan fasting affect sleep?
Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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.
Keywords: Ramadan; sleep; fasting; sleepiness; chronotype
ª2006 Blackwell Publishing Ltd
Voluntary fasting, or the abstinence from food or drink or
both, is practiced in many of the world’s religions and cul-
tures. Fasting during the holy month of Ramadan is the
fourth pillar of Islam, and about 1.5 billion Muslims world-
wide (1,2) fast during Ramadan every year.
Researchers have long recognised that experimental fasting
alters the sleep-wakefulness pattern in various species. For
example, food deprivation has been shown to increase wake-
fulness and to markedly reduce rapid eye movement (REM)
sleep (3–5). The results of experimental fasting, however,
cannot be extrapolated to Ramadan fasting. In experimental
fasting, the duration of each fasting episode is usually more
prolonged than the intermittent fasting during Ramadan.
Moreover, Ramadan fasting has unique characteristics. Dur-
ing every day of the month of Ramadan, Muslims abstain
from food, drink and smoking between dawn and sunset.
Sleep and wake patterns during Ramadan could be affected
by the behavioural restrictions and regime imposed by the
discipline of holy month.
The months in the Islamic (Hijra) year follow the lunar
system. Each Hijra year contains 354 days, or 11 days fewer
than the Gregorian year. As a result, the month of Ramadan
occurs 11 days earlier every year, which means that Ramadan
occurs during a different season every 9 years. The season
during which Ramadan occurs affects the duration of each
fast, because fasting hours are longer in summer than in
winter. This, in turn, may affect sleep patterns, due to factors
such as shorter nights and earlier dawns. In addition, climate
may affect sleep. During the hot summer, many people resort
to napping in the middle of the day, which may influence
night sleep. Moreover, the geographical location may affect
the duration of fasting. As one moves further from the equa-
tor, daytime becomes longer in summer and shorter in winter.
Therefore, when studying sleep patterns during Ramadan, it
is important to document the time of year, the location of the
study and the times of dawn and sunset.
Several other features distinguish Ramadan fasting, includ-
ing the sudden change in the circadian pattern of eating,
whereby caloric intake increases at night, and the long dura-
tion of this practice (1 month), which may allow adaptation
to the new regimen. In addition, there are changes in day-
night activity patterns, such as rising for the predawn meal
(suhur) and prayer, as well as attendant changes in lifestyle
and habits that occur during Ramadan in some Islamic coun-
tries, such as opening of stores and shopping malls until late
at night. All these factors indicate that the physiological and
behavioural changes occurring during the month of Ramadan
may be different from those in experimental fasting (6).
In Islamic countries, many individuals who fast associate
Ramadan fasting with increased daytime sleepiness and
decreased performance. This raises the question whether
Ramadan fasting affects sleep. Although this question has
attracted the attention of researchers in the past few years,
to our knowledge, there has been no review of medical data
addressing the question of sleep during Ramadan. We have
Correspondence to:
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
Tel.: þ966 1 467 1521
Fax: þ966 1 467 2558
REVIEW doi: 10.1111/j.1742-1241.2005.00811.x
ª2006 The Author
Journal compilation ª2006 Blackwell Publishing Ltd Int J Clin Pract, December 2006, 60, 12, 1631–1637
therefore reviewed the findings of research conducted to
assess changes in sleep pattern, chronobiology, circadian
rhythms, daytime sleepiness and function and sleep architec-
ture during the month of Ramadan. Where applicable, these
results have been compared with those obtained during
experimental fasting. References included in this article were
obtained from journals on Medline as well as other peer
review journals posted on the Internet.
In some Islamic countries, working hours during Ramadan
are shorter for those who fast. In such countries, fasting
individuals are allowed to start work at 09:00–10:00 instead
of the usual 07:00–08:00, a change which may affect sleep
patterns. Therefore, it is important to report the working
hours of the studied group, as this may affect the times they
go to bed and wake up.
Surveys of sleep patterns during Ramadan have used dif-
ferent methods to assess bedtime, wake-up time, nighttime
sleep duration and nap time and duration (7–12). Some of
these surveys used a sleep diary, in which each participant
recorded his or her bedtime, wake-up time, nighttime sleep
duration and nap duration every day (7,10,12). Mean values
of these variables were then calculated for each participant.
Other surveys required each participant to state the above
variables the night before and during the preceding day
(8,9). All of these studies, conducted in three Islamic coun-
tries, consistently reported sudden significant delays in bed-
time and wake-up time (Table 1). Interestingly, the delay in
bedtime during Ramadan was reported even by non-Muslim
residents in Saudi Arabia (KSA) (10). The delays in bedtime
and wake-up time during Ramadan reported by fasting
individuals in Islamic countries may be partially due to the
delay in starting work during the month of Ramadan.
For nonfasting individuals, the time of starting work does
not change; however, even for these individuals, bedtime is
significantly delayed during Ramadan (10). These findings
indicate that other factors may affect bedtime during
Ramadan, including the delayed working hours for stores,
shopping malls, and restaurants and the broadcasting of
interesting TV programs until late at night. More than 60% of
fasting individuals who stayed awake after 23:00 attributed
their wakefulness to socialising with families and friends and
watching TV (7,10).
Conflicting results have been reported regarding sleep
duration during Ramadan. When assessing sleep duration,
however, it is important to include both nighttime sleep
duration and daytime naps. In a sample of university students
in Morocco, nighttime sleep duration was reported to drop
significantly during Ramadan (8). A significant reduction in
nighttime sleep duration during Ramadan was also observed
in a sample of medical students in the United Arab Emirates,
but this reduction was ameliorated by increasing the duration
of daytime naps (9). In KSA, however, surveys of medical
students (7) and employed healthy nonsmokers (10) between
the ages of 25 and 55 years found no significant changes in
nighttime sleep duration and total sleep time during the first
and third weeks of Ramadan when compared with baseline
(BL) values. While these studies of medical students and
healthy workers (7,10) found no significant change in the
duration of naps or the percentage of subjects who napped
before and during Ramadan, another study in university
students in Morocco found a decrease in nap duration during
Ramadan (8). Differences among the findings of these studies
may be due to cultural and lifestyle differences in the study
countries, for example, the start times of schools and work are
delayed during Ramadan in some Islamic countries but not in
others. Moreover, many of these studies (7–9) examined
university students, a group of subjects prone to psychological
and physical stresses due to the transitional nature of college
life (13).
In summary, studies have demonstrated several modifica-
tions in sleep patterns during Ramadan, including sudden
and significant delays in bedtime and wake-up time. How-
ever, conflicting results have been reported regarding total
sleep time. Thus, larger scale studies, with reliable assessment
of total sleep time among fasting individuals in Islamic and
non-Islamic countries during Ramadan, are needed.
Some of the changes associated with Ramadan may have some
impact on the circadian rhythms and biological clock of
Table 1 Bedtime and wake-up time before and during Ramadan
Baseline Beginning of Ramadan End of Ramadan p-Value Reference
Bedtime, h h 23.4 3.5 2.8 2.9* 3.2 2.1* 00.05 7 (mean SD) (n¼56)
Wake-up time, h h 6.6 0.9 8.3 0.9* 8.95 0.4* 00.001
Bedtime, h min 00:36 14 02:06 16* 02:36 19* ¼0.001 10 (mean SE) (n¼41)
Wake-up time, h min 06:36 13 08:36 8* 08:48 9* ¼0.001
Bedtime, h min 23:48 7 00:36 11 00:41 13 0.0024 11 (mean SE) (n¼8)
Wake-up time, h min 08:03 6 08:52 17 09:08 17 0.016
*Significant compared with baseline.
ª2006 The Author
Journal compilation ª2006 Blackwell Publishing Ltd Int J Clin Pract, December 2006, 60, 12, 1631–1637
individuals during that month. Those who fast during
Ramadan usually eat 2–3 meals per day: breakfast at sunset,
dinner after night prayer (17:00–20:00) and a predawn meal.
The eating of meals exclusively at night may therefore affect
circadian rhythms during the fast. Body temperature normally
follows a circadian rhythm, rising during the day and falling
at night. In general, a falling body temperature induces sleep,
whereas a rising temperature provokes wakefulness (7). When
a rectal thermistor probe was used to record body temperature
continuously for 24 h in six subjects during Ramadan, delays
were observed in the occurrence of acrophase and bathyphase
(i.e. the times at which the maximum- and minimum-calcu-
lated values, respectively, occur in the cycle), as well as a
reduction in the amplitude (11). Another study of fasting
during Ramadan found that oral temperature significantly
decreased at 09:00, 11:00, 13:00 and 16:00 and significantly
increased at 23:00 and 00:00 h (14). Similar changes in body
temperature were not observed in another study that meas-
ured oral temperature using a high-precision medical thermo-
meter at 08:00, 16:00 and 00:00 during the first and third
weeks of Ramadan (12).
Melatonin is considered to be one of the best markers for
circadian rhythm disruption (14,15), as individual melatonin
profiles are highly reproducible and are less subject to mask-
ing factors than are other rhythm markers like core tempera-
ture and cortisol (16). Thus, changes in the circadian pattern
of body temperature during Ramadan may be accompanied
by alterations in the circadian pattern of secretion of this
hormone. In an assessment of melatonin levels from blood
samples obtained every 4 h, omitting the 02:00 point to avoid
any sleep disturbances, before and on the 23rd day of Rama-
dan, a smaller delayed night peak and a flatter slope of serum
concentrations of melatonin were observed during Ramadan
(17). Using saliva samples obtained at three time points over
a 24-h period (08:00,16:00 and 00:00), one week before
Ramadan and on the 7th and 21st days of Ramadan, there
were significant decreases in melatonin concentrations at
00:00 and 16:00 during Ramadan relative to BL (12). Never-
theless, melatonin profiles showed the same trend during
Ramadan, but with a flatter slope (Fig. 1). In both studies,
however, melatonin concentrations were not measured late at
night, thus omitting any late peaks in melatonin concentra-
tion. Therefore, future studies should measure melatonin con-
centrations more frequently after midnight.
Melatonin concentration has been reported to decrease
during fasting, even during short-term experimental fasting
(18,19). Although the exact mechanisms underlying the
reduced levels of melatonin during fasting are not known,
proposed mechanisms include increases in nocturnal cortisol
levels during Ramadan (20,21) and decreased melatonin
synthesis secondary to decreased glucose provision (22). In
support of the latter, malnourished rats have been found to
have less melatonin in the pineal gland than normally fed
animals, an effect attributed to mild hypoglycaemia, which
reduces the level of N-acetyltransferase, an enzyme involved
in the synthesis of melatonin, in starving rats (23). In fasting
individuals, reduced melatonin level was found to be asso-
ciated with mild hypoglycaemia, whereas glucose supplemen-
tation during fasting returned the decreased melatonin level
to normal (19). This, however, may not explain the
decreased melatonin level observed during Ramadan fasting,
as hypoglycaemia is thought not to occur in fasting healthy
individuals during the holy month (6). Another hypothesis
proposed to explain reduced melatonin levels during fasting
is the reduction in tryptophan, which is both an essential
amino acid and a precursor of melatonin. This is unlikely,
however, because glucose supplementation restored normal
melatonin secretion (19).
Another way to assess circadian rhythms is to assess the
chronobiology of fasting individuals. When we measured
chronotype in fasting and nonfasting individuals using an
abridged version of the Horne and O
¨stberg questionnaire
(morningness eveningness test) (a questionnaire that estab-
lishes three behavioural categories: morning type, neither
type and evening type) (10,24), we observed a trend towards
an increase in evening types among fasting individuals, both
at the beginning and the end of Ramadan compared with
BL. Similar findings were observed in fasting Muslims in
Morocco (8). Interestingly, a change in chronotype was
demonstrated in nonfasting non-Muslim residents in KSA
during Ramadan (10). Among these individuals, there was a
trend towards an increase in noon types and a decrease in
morning types at both the beginning and end of Ramadan
when compared with BL.
In summary, changes in the circadian rhythm and chrono-
biology have been demonstrated in fasting individuals during
Ramadan. This is manifested as a change in the circadian
12 midnight 8
am 4
Melatonin level
a, b
a, b
Figure 1 Circadian pattern of saliva concentrations of melatonin
during baseline (BL), 1st week of Ramadan (R1) and 3rd week of
Ramadan (R3). a and b indicate significant difference (p 00.05)
(a, BL vs. R1 and b, BL vs. R3) (12). Reproduced with permission
ª2006 The Author
Journal compilation ª2006 Blackwell Publishing Ltd Int J Clin Pract, December 2006, 60, 12, 1631–1637
pattern of body temperature, a decrease in the amplitude of the
melatonin rhythm and a nocturnal increase in cortisol level.
Daytime Sleepiness and Alertness
Studies have assessed daytime sleepiness subjectively (7–10,
12,25) using the Epworth sleepiness scale (ESS), which is a
validated reliable sleep questionnaire that measures the
general level of daytime sleepiness (26), and objectively
using the multiple sleep latency test (MSLT) (12,25), with
the latter test used to determine mean sleep latency during
standardised daytime naps as an objective measure of daytime
sleepiness; the presence absence of REM sleep during
the naps is also determined. Although some studies using
the ESS have reported a significant increase in daytime sleepi-
ness during the entire month of Ramadan (7,8), others found
no significant change (9,10,12). When subjective alertness
was assessed during Ramadan using a visual analogue scale,
decreases in alertness were observed at 09:00 and 16:00,
whereas an increase was observed at 23:00 (14). Other studies
that used a 24-h time scale to determine the time of the day
at which each participant felt most alert and most sleepy
showed no differences between BL and Ramadan (Fig. 2;
7,10). These studies, however, recruited different groups of
volunteers, with some including medical and university stu-
dents, who may have had irregular sleep habits or a shortening
of mean sleep length due to life constraints.
Two objective studies used the MSLT to evaluate sleepiness
under controlled conditions (12,25). Because all participants
had to be studied within a limited time (the month of
Ramadan), there were constraints on the number of recruited
volunteers, with each study including only eight subjects. In
one study, increased daytime sleepiness at 10:00 and 12:00
was reported towards the end of Ramadan (25). However,
this study used a portable, at home polysomnography-
recording device, which forced the operator to program the
computer to end the test 20 min after the beginning of
recording, regardless of sleep onset. Therefore, none of the
participants slept long enough to progress to REM sleep. In
the other study (12), a standard MSLT (27) was performed
in the sleep laboratory, avoiding the limitation of the
previous study. No differences in sleep latency, sleep onset
Figure 2 A) Time of the day when
subjects felt most sleepy before and
during the first 3 weeks of Ramadan. B)
Time of the day when subjects felt most
alert before and during the first 3 weeks
of Ramadan. (BL, baseline data; R1, first
week of Ramadan; R2, second week of
Ramadan; R3, third week of Ramadan)
(7). Reproduced with permission
ª2006 The Author
Journal compilation ª2006 Blackwell Publishing Ltd Int J Clin Pract, December 2006, 60, 12, 1631–1637
frequency and wake efficiency were observed between the
first and third weeks of Ramadan and BL (12). Delta or
slow wave activity during non-REM (NREM) sleep is
considered a classic marker of the homeostatic process. In
contrast, high levels of electro-encephalographic (EEG)
alpha activity during wakefulness and NREM sleep may
indicate a high level of alertness (28). Spectral analysis of
the EEG activity during each nap showed no differences
between Ramadan and BL (12).
Daytime Function
Daytime function during Ramadan has yet to be assessed
properly under controlled conditions. During the first week
of Ramadan, psychomotor performance indicators such as
critical flicker fusion (29) and choice reaction time (14)
have been reported to be impaired. The latter of these studies
also found that sleep duration during Ramadan was 1 h less
than BL (14). Even this modest sleep restriction may impact
on daytime sleepiness and functioning (30). The percentage
of medical students who reported falling asleep in class
increased from 15% at BL to 36% during the first week of
Ramadan (7). However, sleep deprivation or disruption can-
not be ruled out as possible confounders in previous studies,
as the participants’ sleep duration and quality were not
assessed objectively before and during Ramadan. An experi-
mental study of individuals subjected to 1 week of controlled
underfeeding and whose sleep was monitored by polysomno-
graphy found that during fasting, the study subjects showed
increased daytime energy, concentration and emotional bal-
ance (18). Another study found a decrease in mood rating
during Ramadan (14), but a second study did not observe this
effect (31). Given that sudden delays in bedtime have been
associated with adverse mood changes resembling those of
depression (32,33), the effect on mood of the sudden delay
in bedtime during Ramadan requires further assessment.
Although the percentage of subjects who exercise regularly
dropped from 24% before Ramadan to 5% at the end of
Ramadan (7), the reason for this decline is not clear.
In summary, the notion that Ramadan fasting affects day-
time sleepiness and functioning is not supported by the
available data. More research is needed to elucidate this issue,
while controlling for potential confounders like sleep
deprivation. Researchers should also remember that fatigue
and alertness do not always parallel sleepiness (34). Sleepiness,
alertness and fatigue may be symptoms of poor sleep, but
testing by independent evaluations is required.
Two studies have assessed sleep architecture during Ramadan
using polysomnography: one used ambulatory 8-channel
unattended recording at home (11), and the second used full
attended in-laboratory polysomnographic recording (12)
(Table 2). Both studies demonstrated a significant reduction
in REM sleep towards the end of Ramadan, which contrasts
with findings of increased REM sleep during experimental
fasting in humans (18). However, the fasting pattern in the
experimental study was controlled underfeeding rather than
intermittent fasting. An experimental study conducted on
piglets demonstrated that REM sleep did not occur after
18 h of fasting but recurred after feeding (35). The reduction
in REM sleep during fasting may be due to a nocturnal rise in
cortisol and insulin (36–38). Nocturnal body temperature has
been reported to increase during sleep (11,14). Because REM
sleep is inversely proportional to core temperature (39,40), a
nocturnal increase in temperature would be expected to
decrease REM sleep (41,42). Another possible explanation
for the reduction in REM sleep during Ramadan is the
interruption of sleep for the predawn meal during the early
morning hours, the time period in which a larger amount of
REM sleep usually occurs.
Conflicting results have been reported with regard to sleep
latency and total sleep time. While one study reported a
Table 2 Polysomnographic characteristics before and during Ramadan
Baseline Beginning of Ramadan End of Ramadan p-Value Reference
TIB (min) 440.2 9.3 472.6 10.9 476.3 4.8 NS 12 (mean SE) (n ¼8)
TST (min) 361.7 39 379.0 36.0 378.0 35.0 NS
Sleep latency (min) 35.0 12.0 30.4 17 18.5 10* 0.05
REM percentage (TST) 24.1 3.9 21.5 4.2 10.2 5.0* 0.003
Arousal index 19.9 6.8 18.1 10.9 19.0 11.0 NS
Stage shifts 94.0 23.5 95.0 23.8 101.8 22.0 NS
TIB (min) 454 4.7 406 11.9* 422 14.9 00.01 11 (mean SE) (n ¼8)
TST (min) 422 9.0 381 11.6* 383 16.7* 00.05
Sleep latency (min) 19.2 2.6 60.5 10.6* 58.1 14.8* 00.01
REM sleep (min) 94.3 5.2 88.5 6.6 74.7 5.3* 00.01
NS, nonsignificant; TIB, time in bed; TST, total sleep time. *Significant compared with baseline.
ª2006 The Author
Journal compilation ª2006 Blackwell Publishing Ltd Int J Clin Pract, December 2006, 60, 12, 1631–1637
significant drop in sleep latency at the end of Ramadan and
no change in total sleep time (12), a second study (11)
reported a significant increase in sleep latency and a signifi-
cant reduction in total sleep time. The discrepancy between
these results may be due to the amounts of time between
dinner and bedtime. In one study (11), the difference between
dinnertime and bedtime was 1 h (dinner was served at 22:30
and polysomnographic recording started at 23:30), whereas,
in the second study (12), the difference was 3 h (dinner was
served at 21:00 and recording started at 00:00). Because late
dinner may affect nocturnal sleep, future research should
consider the relation between dinnertime during Ramadan
and nocturnal sleep.
No significant differences were demonstrated between
Ramadan and BL with regard to NREM sleep stages, arousal
index, stage shifts and cardio-respiratory parameters (12).
Using an experimental model of fasting, significant reductions
were observed in the number of arousals and arousal index, as
well as a significant reduction in periodic leg movement
(PLM) during fasting (18). Although no differences in PLM
before and during Ramadan have been reported (12), the
mean PLM in the latter (12) was not high compared with
that in the former (18).
In summary, a reduction in the proportion of REM sleep
has been reported during Ramadan, although these studies
have shown conflicting results with regard to sleep latency
and total sleep time. Larger studies that control for different
confounders, such as the time of the dinner meal, are needed.
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... starvation-induced increase of lipid components in blood [46] and iii. environmental and occupational determinants of health [49]. As a matter of fact, the alteration of sleep duration and timing as well as the subsequent changes in energy expenditure and light exposure have been recognized as major cofounders by a number of systematic reviews and metaanalytical assessments [50,51]. ...
... As a matter of fact, the alteration of sleep duration and timing as well as the subsequent changes in energy expenditure and light exposure have been recognized as major cofounders by a number of systematic reviews and metaanalytical assessments [50,51]. Simultaneously, sleeping time and patterns can also be affected by temperature and geography; Muslims residing in Greece and Muslims residing in Australia are quite likely to observe Ramadan RF in different temperature and day-and night-time allocation [49]. It is also noteworthy, that Muslim expatriates in non--Muslim countries have limited access to Ramadan--fit foods in comparison to Muslims residing in predominantly Muslim countries. ...
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Religious fasting (RF) is practiced annually by millions of Christian and Muslim followers worldwide. Scarce data exist on the impact of RF on the metabolic and hematological profile of individuals with or without dyslipidemia. The present study included: (i) 60 Greek Orthodox participants, 30 with dyslipidemia and 30 without dyslipidemia, who abstained from meat, fish and dairy products for seven consecutive weeks, and (ii) 15 young, non-dyslipidemic Muslim participants abstaining totally from food and liquid from dawn till sunset during 30 days. Biochemical (iron, ferritin, vitamin B12, calcium, low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), triglyceride and fasting glucose) and hematological (hemoglobin, hematocrit) serum blood test results of study participants were measured pre- and post- RF (at weeks 0 and 7 for Orthodox participants and at weeks 0 and 4 for Muslim participants). In dyslipidemic and non-dyslipidemic Orthodox participants, a significant reduction of fasting glucose, HDL, LDL and TC levels was found post-RF. Hemoglobin, hematocrit, iron and ferritin levels were significantly increased, while post-RF vitamin B12 and calcium levels were substantially decreased. Subanalysis between dyslipidemic and non-dyslipidemic Orthodox participants revealed a greater decrease of cholesterol levels in the former. In Muslim participants, triglyceride, LDL and total cholesterol levels were increased post-RF (all p values < 0.05). Our study adds to the existing literature evidence about the significant impact of RF on metabolic and hematological profiles of Orthodox and Muslim followers. The prevention of calcium and B12 deficiency during Orthodox RF by supplement consumption as well as the protection from dehydration and dysregulation of lipid metabolism during Ramadan RF should concern both clinicians and dietician nutritionists. Nevertheless, studies with larger sample size and/or long-term follow-up are warranted before reaching definite conclusions about the effects of RF on human health.
... In contrast, the findings of the present study do not support some previous research that showed no changes in body mass or dietary intake among athletes during RIF [34,35,37]. Those results were explained by the common belief that athletes are likely to overcompensate for their reduced food and fluid intakes during RIF, especially during Sahur [38,39]. ...
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The objective of this study was to assess the effects of an additional small-sided games (SSGs) training program during Ramadan intermitting fasting (RIF) on technical performance depending on changes in body composition, sleep habits, and ratings of perceived exertion (RPE). Twenty-four professional male basketball players from the Tunisian first division participated in this study. The players were randomly assigned to an intervention group (INT; n = 12) or an active control group (CON; n = 12). Both groups completed a four-week SSG training program (three sessions per week). During the first and fourth weeks of the SSGs training, the two groups were evaluated to detect changes in technical performance, dietary intake, body composition, sleep quality index (PSQI) survey outcomes, RPE, heart rate (HR), and blood lactate concentration [La]. During the fourth week of the RIF period, body composition, dietary intake, sleep latency, sleep duration, and HR significantly decreased only for INT (p < 0.001). However, RPE significantly increased (p < 0.001), and technical performances were negatively affected (p < 0.01). MANCOVA (adjusted for the percentage of change in sleep duration, body mass, and RPE) showed no significant differences in either group. In conclusion, our results showed that the technical performance of professional basketball male players was significantly affected at the end of RIF independently of changes in RPE, sleep habits, and body composition.
... The accredited international medical societies and renowned religious organizations continue to publish evidence-based guidelines concerning Ramadan fasts for diabetic patients [3e5]. The blood glucose levels and other metabolic markers of diabetic patients (with fasting status) markedly change during Ramadan due to a reciprocal alteration in their eating habits, working hours, sleeping times, and daily physical activities [6]. ...
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Aims: Ramadan is a holy month for the Muslim community. Fasting Ramadan is directed by a systematic alteration in eating habits, sleeping times, and daily physical activities that optimize blood glucose levels. This study aims to evaluate the effects of structured education on safe fasting among diabetic patients. Method This study included diabetic patients with eligibility for the Ramadan fast. The control group included 494 patients who received standard diabetes education, while the intervention group included 407 patients who attained structured diabetes education. The patients were required to register their responses following the written, structured questionnaires before and after Ramadan fasts. In addition, patients were advised to keep a log of their hypoglycemic episodes. Result This study showed that structured diabetes education improved the blood glucose levels/glycemic control and outcomes of patients during their Ramadan fasting. The structured diabetes education helped reduce the incidence of hypoglycemic events and hyperglycemic crises. It also increased the acceptance and frequency of blood sugar level measurements among patients during Ramadan. Conclusion The standard diabetes management plan should include structured diabetes education measures to improve outcomes effectively. The providers should screen the patients with diabetes before Ramadan and educate them to improve their safe fasting practices.
... 8 Ramadan also alters sleeping patterns due to changing eating habits (Roky et al., 2000(Roky et al., , 2001, but there is not much evidence on how it affects the total amount slept. The limited evidence we have shows that people partially adapt by sleeping more during the day and less at night (Margolis and Reed, 2004;Bahammam, 2006). Moreover, changes in sleep patterns may depend on whether working hours are adjusted. ...
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I study the impact of hunger on traffic accidents by exploiting the fasting that is religiously mandated during the month of Ramadan. Identification comes from working hours not being adjusted during Ra-madan in Turkey. I find that driving while fasting at rush hour is associated with a significant increase in road traffic accidents. Using existing survey evidence on fasting rates in Turkey, I conclude that hunger induced by fasting increases the probability of an accident by 25%, which is smaller than the effect of driving while intoxicated, but larger than the effect of mild sleep deprivation. JEL Classification: I18, R41, Z12.
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The combined effect of Ramadan fasting and the time of theday on the physical performance of team-handball players has not yet been fully investigated. This study investigated the effects of Ramadan fasting on the morning–evening difference in team-handball-related short-term maximal physical performance. With acounterbalanced study design, 15 elite female team-handball players underwent the hand grip (HG), ball throwing velocity (BTV), modified agility T-test (MAT), and repeated shuttle-sprint and jump ability (RSSJA) tests at 07:00 h and 17:00 h, one week before Ramadan (BR), and during thesecond (SWR) and fourth week of Ramadan (4WR). The oral temperature (OT) was monitored prior to exercise and the ratings of perceived exertion (RPE) scale were obtained after RSSJA. The results showed that the time of theday had an effect on OT under all conditions. The HG, BTV, and MAT test performances were higher in the evening than in the morning BR (P< .001, P< .05, and P< .001, respectively). However, the diurnal variation noted in the HG and MAT tests was reversed during the SWR and 4WR, while the BTV variation was blunted during the SWR and reversed during the 4WR. The best RSSJA performance was observed in the evening BR. However, for the best and mean sprint times, areversal of this diurnal variation was observed, which was blunted for the mean jump height and sprint time decrement during Ramadan. Moreover, RPE were influenced by the time of theday and the month of Ramadan. These findings suggest that the diurnal variation of team-handball-related short-term maximal physical performance may be reversed and/or blunted during Ramadan fasting.
Objectives Ramadan intermittent fasting may affect whole-body metabolism by affecting appetite-related hormones. This systematic review and meta-analysis aimed to clarify the possible effects of Ramadan intermittent fasting on the main hormones regulating appetite and satiety, including leptin and adiponectin.Methods All English language papers in the PubMed, Scopus, and Embase databases were searched using the keywords “Ramadan fasting”, “adiponectin”, and “leptin”, up to 2020. Data extraction was conducted based on the main data of the studies; the primary outcomes of the analysis were mean changes of adiponectin and leptin levels during the holy month of Ramadan in fasted subjects.Main resultsData of 16 eligible studies, conducted between 2003 and 2020, were included in the systematic review. Of these, 10 studies with complete data on leptin and adiponectin were included in the meta-analysis. A significant decrease in leptin levels was observed after Ramadan fasting (WMD = −2.28 ng/ml, 95% CI = −3.72, −0.84). Ramadan fasting had no significant effect on adiponectin levels (WMD = 2.19 ng/ml, 95% CI = −0.29, 4.67). Sub-group analysis demonstrated a greater decrease in leptin levels among normal-weight subjects compared to those of overweight/obese subjects (WMD = −4.67 ng/ml, 95% CI = −6.03, −3.31 vs. WMD = −3.43 ng/ml, 95% CI = −5.69, −1.17).Conclusion Ramadan fasting may decrease leptin levels, especially in normal-weight subjects. There was high heterogeneity, which may be explained by the differences between the wide ranges of study conditions.
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The Saudi Center for Disease Prevention and Control recently prepared a Consensus Statement regarding how much time a person should spend engaged in physical activity, sedentary behavior, and sleep to promote optimal health across all age groups. This paper describes the background literature, methodology, and modified RAND Appropriateness Method and GRADE-ADOLOPMENT approach that guided the development process. A Leadership Group and Consensus Panels were formed, and credible existing guidelines were identified. The Panel identified clear criteria to choose the best practice guidelines for the set objectives after evaluation based on GRADE table evidence, findings table summaries, and draft recommendations. Updating of the selected practice guidelines was performed, and the Consensus Panels separately reviewed the evidence for each behavior and decided to adopt or adapt the selected practice guideline recommendations or create de novo recommendations. Data related to cultural factors that may affect the studied behaviors, such as prayer times, midday napping or “Qailulah”, and the holy month of Ramadan, were also reviewed. Two rounds of voting were conducted to reach a consensus for each behavior.
Objectives Hydration and nutrition are critical to achieving optimal performance. This study aimed to assess the impact of limited oral intake in the operating room environment on surgical resident health, well-being, and performance. Design Electronic survey was sent to 94 surgical trainees at our institution in 2020. Chi-square analyses were performed to assess for differences in survey responses by sex. Setting A single tertiary-care institution. Participants Surveys were sent to surgical residents and fellows in general surgery, neurosurgery, and orthopedic surgery. Seventy-nine (80%) of the 94 residents and fellows responded. Results Of the 79 responses, most trainees (79%) experienced dehydration within 6 hours of operating. Forty-four (56%) reported no fluid intake for greater than 6 hours on average, and 39 (49%) reported that they frequently had difficulty rehydrating in between cases. Most of the respondents (70%) frequently experienced symptoms of dehydration, including orthostasis, headache, and constipation. Fifty-six (71%) believed that dehydration frequently affected their performance. Compared to men, women were more likely to feel dehydrated within 4 hours of operating (58% vs. 25%, p = 0.005). Women were also more likely to have difficulty rehydrating in between cases (75% vs. 38%, p = 0.0026), experience symptoms of dehydration (92% vs. 60%, p = 0.0049), and report that dehydration affects surgical performance (88% vs. 64%, p = 0.0318). Conclusions Prolonged fasting and dehydration are common issues that may negatively impact performance and wellbeing of surgical trainees. Also, dehydration may affect men and women differently.
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The pineal gland participates in the internal temporal organization of the vertebrate organism by the rhythmic synthesis of its hormone melatonin. This hormone is considered the darkness hormone because of its unique feature of being synthesized exclusively at night, regardless of the organism activity pattern. The presence and absence of this indolamine help to mark, respectively, dark and light time, i.e., night and day, to the organism. Moreover, the daily duration of the secretory episode of melatonin, synchronized to the duration of the night in the environment, times the several physiological regulatory processes in order to adapt the organism to the annual seasonal environmental variation. The mechanisms of melatonin production are different among the several classes of vertebrates. In fishes, amphibians, some reptiles and birds, the pineal gland is photosensitive, whereas in mammals the photosensitivity is absent. In this case, the light periodical information is conveyed to the gland through a neural pathway that originates in the retina, projects to the hypothalamic suprachiasmatic region, including the suprachiasmatic nuclei (the circadian biological clock in vertebrates) and, then, indirectly to the pineal gland. The signal that stimulates melatonin synthesis during the dark period of the daily light/dark cycle, in mammals, is the neurotransmitter noradrenaline, which is released from the sympathetic terminals of neurons whose cell body are located in the superior cervical ganglia. This transmitter interacts with adrenoreceptors in the pinealocytes membrane, resulting in cAMP and calcium elevation that induces melatonin synthesis. The signaling cascade that involves cAMP triggers and/or increases the arylalkylamine N-acetyltransferase transcription and translation, as well as its activation by phosphorylation and association with 14-3-3 protein. This enzyme converts serotonin into N-acetylserotonin that is then transformed by hydroxyindole-O-methyltransferase into melatonin. These two steps occur only at night. Melatonin, immediately after being synthesized, is released to the systemic circulation and it influences almost every physiological function in the organisms. It regulates the circadian clock, rest-activity and wake-sleep cycles, immunological system, energy metabolism and many other functions. Melatonin also influences the seasonal rhythms through the variation observed in its plasmatic profile duration according to the length of night. Among the seasonal physiological functions modulated by melatonin are reproduction, immune response, and metabolic adaptations and weight. Melatonin is an ancestral molecule as it appears soon in the evolutionary chain and it is ubiquitous in the living organisms. It seems that early in evolution melatonin could have had an anti-oxidative role, protecting the primitive life from the possible oxidation process mainly dependent on light and aerobiosis. This property is still conserved by its intracellular direct interaction with other molecules involved in oxidation. Besides, melatonin has its proper receptors, known as MT1, MT2 and MT3 which are found in the central nervous system and peripheral organs. Thus, melatonin is part of a photo-neuroendocrine temporal system, which adapts the organisms to the external environmental cyclic fluctuations, like day and night and the seasons, regulating most of the physiological regulatory processes, including insulin synthesis and action, playing a putative role in the pathophysiology of diabetes mellitus.
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We assessed the effect of Islamic fasting and its attendant changes in lifestyle on total sleep time, sleep habits, daytime sleepiness, and eating habits in a group of young healthy subjects during the first 3 weeks of Ramadan. A self-administered questionnaire was designed and given four times: 1) 1 week before Ramadan (baseline, BL), and 2) the first week (R1), 3) second week (R2), and 4) third week of Ramadan (R3) to assess sleep habits, daytime sleepiness and functioning, and eating habits. During weekdays, participants were asked to monitor their sleep habits and other parameters described in the questionnaire, and then to complete the questionnaire on the last weekday of each week, according to the timetable set in the study design. Complete information was available for 56 participants. Bedtime was delayed significantly during Ramadan as compared to BL. Total sleep time at night (TST) dropped slightly during Ramadan as compared to BL, but this drop did not reach statistical significance. Despite the insignificant change in TST, Epworth Sleepiness Scale (ESS) scores were significantly higher during Ramadan. The present study revealed several modifications in circadian rhythm, social activity, and eating habits of fasting individuals during the month of Ramadan. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Fasting during Ramadan is distinct from regular voluntary or experimental fasting. This project was conducted to objectively assess the effect of Ramadan fasting on sleep architecture, daytime sleepiness and the circadian cycle of melatonin level. Eight healthy volunteers reported to the Sleep Disorders Center on four occasions for polysomnography and multiple sleep latency tests: 1) an initial visit for adaptation; 2) 2 weeks before Ramadan (BL); and 3,4) during the first and third weeks of Ramadan (R1, R3). Salivary melatonin level was measured using radioimmunoassay. Sleep latency at night was significantly shorter and the amount of rapid eye movement sleep was significantly less, at R3 compared to BL. There was no difference in multiple sleep latency test data between BL and Ramadan. Although melatonin level kept the same circadian pattern at BL, R1 and R3, it had a flatter slope and a significantly lower peak at midnight (00:00) at R1 and R3. This study showed a significant reduction in sleep latency and rapid eye movement sleep during the third week of Ramadan fasting. Otherwise, there was no significant effect of Ramadan on sleep architecture and assessment revealed no increase in daytime sleepiness. Although melatonin level had the same circadian pattern during Ramadan, the level of the hormone dropped significantly from baseline.
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An English language self-assessment Morningness-Eveningness questionnaire is presented and evaluated against individual differences in the circadian vatiation of oral temperature. 48 subjects falling into Morning, Evening and Intermediate type categories regularly took their temperature. Circadian peak time were identified from the smoothed temperature curves of each subject. Results showed that Morning types and a significantly earlier peak time than Evening types and tended to have a higher daytime temperature and lower post peak temperature. The Intermediate type had temperatures between those of the other groups. Although no significant differences in sleep lengths were found between the three types, Morning types retired and arose significantly earlier than Evening types. Whilst these time significatly correlated with peak time, the questionnaire showed a higher peak time correlation. Although sleep habits are an important déterminant of peak time there are other contibutory factors, and these appear to be partly covered by the questionnaire. Although the questionnaire appears to be valid, further evaluation using a wider subject population is required.
Electroencephalographic (EEG) activity is a key indicator of a vigilance state, and quantitative analyses of the EEG have revealed profound differences both between and within vigilance states in humans. We summarize recent studies that investigated how the spectral composition of the EEG during the three vigilance states, that is, wakefulness, rapid eye movement (REM) and non-REM sleep, is modulated by a circadian oscillator, which is independent of sleep–wake behavior, and by the sleep–wake oscillation itself, that is, elapsed time awake and elapsed time asleep. The data collected in sleep deprivation experiments and in protocols in which the sleep–wake cycle was desynchronized from endogenous circadian rhythmicity show that both factors contribute to this variation in a frequency- and state-specific manner. Low frequency EEG activity, including slow waves and theta frequencies, during both wakefulness and non-REM sleep, gradually increases with elapsed time awake and progressively declines with elapsed time asleep. The EEG activity in this 0.75–8 Hz frequency range is not markedly affected by circadian phase. In contrast, alpha activity (8–12 Hz) during wakefulness and REM sleep, as well as sleep spindle activity (12–15 Hz) during non-REM sleep, show a robust circadian regulation. Circadian and sleep–wake dependent regulation of EEG activity within the vigilance states also exhibits topographical variation such that frontal brain areas are more susceptible to the effects of the sleep homeostat than more parietal brain regions. It will be challenging to identify the functional correlates of these different spectral EEG patterns and relate them to neurobehavioral performance and recovery functions of sleep.
Continuous EEG recordings were performed in lean (240–250 g) rats, in large size (300–380 g) rats and in Ventromedial Hypothalamic (VMH) lesioned obese (450–470 g) rats, during 4 days of food deprivation and 3 days following food restitution. Though the daily amounts of both Slow Wave Sleep (SWS) and Paradoxical Sleep (PS) were dramatically decreased in lean rats (particularly during the dark phase of the day) by the food deprivation, they remained unchanged in large size rats and also in VMH obese rats. In the latter, there was even a tendency to an increase of SWS during the first two days of starvation. Food restitution brought about a significant rebound in SWS and PS (largely based upon an increase during the dark phase of the diurnal cycle) in lean rats, but had no effect on the sleep parameters of large size and VMH obese rats. Replacement by glucose infusions (100% of the normal daily caloric intake) via a cardiac catheter of oral nutrients in food deprived rats also resulted in a similar increase of sleep duration. These findings suggest that sleep is dependent on the degree of availability of metabolizable substances at the cellular level. In addition, possible causative relations between sleep and feeding are discussed.
Continuous telemetric EEG recordings served to determine the vigilance states of the rat during 2 control days, 80 h of food deprivation and 64 h following restitution of food. The recordings were supplemented by measurements of food intake, water intake and motor activity. The following 3 sleep parameters were not significantly changed by food deprivation: the daily amount of the vigilance states, the light-dark distribution of sleep and waking, and the 10 min paradoxical sleep (PS) cycle. During food deprivation, PS was depressed in the dark phase of the diurnal cycle and increased in the light phase. The sleep parameter that was most affected by food deprivation was the duration of sleep episodes. Episodes of slow-wave sleep (SWS) and PS were shortened only in the dark phase of the deprivation days, whereas total sleep episodes were progressively decreased in both diurnal phases. After restitution of food, the episodes of SWS and total sleep were immediately lengthened and tended to exceed the control level. The duration of feeding episodes and meal size were significantly increased in comparison to pre-deprivation values, whereas feeding frequency was decreased. Long episodes of continuous motor activity occurred during the dark phase of the refeeding period, while a fragmented activity pattern was typical for the deprivation nights. It is proposed that the adjustment of the length of behavioral episodes may constitute an important adaptive mechanism for the rat.
To investigate the impact of national and religious events on the rate of parasuicide, a comparison was made between the number of reported parasuicides during the month of Ramadan and the month before and after Ramadan in Jordan, for the years from 1986 to 1991. Significantly fewer parasuicides were reported during Ramadan than the month preceding it and the month that follows Ramadan. The findings confirm previous observations that national events reduce the rate of parasuicide, but the protective effect does not persist into the month that follows Ramadan.