How does diurnal intermittent fasting impact sleep, daytime sleepiness, and markers of the biological clock? Current insights

Ramadan fasting observance is associated with decreased sleep duration, increased daytime sleepiness and insomnia symptoms among student-athletes

OBJECTIVE

To examine the relationships between Ramadan fasting observance (RFO) and sleep-wake patterns, daytime sleepiness, and insomnia levels in student-athletes.

METHODS

Sleep was measured using wrist-actigraphy in 25 semi-professional student-athletes (mean ± SD; age = 22 ± 2 years, height = 182.0 ± 5.8 cm, body mass = 81.3 ± 15.2 kg) during seven nights before RFO (academic study period), during the first half of RFO (14 nights, holiday period), and the second half of RFO (14 nights, academic study period). Additionally, participants completed the Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI) questionnaires seven days before RFO and on the last day of RFO.

RESULTS

Actigraphy results indicated RFO was associated with significant decreases in sleep duration during the second half of RFO vs. before and during the first half of RFO (p < 0.001). However, the first half of RFO was associated with a delay of ⁓ 2.5 h in sleep onset compared to before RFO; this delay persisted during the second half of RFO (p < 0.001). The total PSQI score before RFO (6.6 ± 2.3 AU) and during RFO (8.2 ± 2.3 AU) suggested poor overall sleep quality. ISI and ESS scores were greater during than before RFO (p = 0.002 and p = 0.041, respectively).

CONCLUSIONS

The second half of RFO was associated with decreases in objectively assessed sleep duration among student-athletes. RFO was also associated with impaired sleep quality, excessive daytime sleepiness, and increased insomnia symptoms. Personalized interventions to address sleep-related issues in student-athletes during RFO are warranted.

Chrono-nutrition and sleep: lessons from the temporal feature of eating patterns in human studies - A systematic scoping review

An emerging field of research has revealed a bidirectional relationship between sleep and diet, highlighting the potential role of a healthy diet in improving sleep. However, the impact of chrono-nutrition on sleep remains less explored. Here we conducted a systematic scoping review, considering the multiple dimensions of chrono-nutrition, to describe the extent, range, and nature of the existing literature in this area (PROSPERO: CRD42021274637). There has been a significant increase in the literature exploring this topic over the past six years (almost 67 % of the evolving literature). A breakdown of the included studies was performed according to three major chrono-nutritional dimensions: meal timing [n = 35], irregular eating patterns [n = 84], and frequency of eating occasions [n = 3]. Meal timing included three sub-dimensions: breakfast skipping [n = 13], late eating [n = 16], and earlier vs later meals schedules [n = 6]. Irregular meal patterns included three sub-dimensions: diurnal fasting [n = 65], intermittent fasting [n = 16], and daily meal patterns [n = 3]. Frequency was the least studied dimension (n = 3). We provided a synthetic and illustrative framework underlining important preliminary evidence linking the temporal characteristics of eating patterns to various facets of sleep health. Nonetheless, much work remains to be done to provide chrono-nutrition guidelines to improve sleep health in the general population.

Determining the Effects of Ramadan Fasting on Risky Behaviors of Turkish Nursing Students

The aim of this study was to determine the effect of nursing students' fasting during Ramadan on their risky behaviors. This study was conducted in a university located in 2022 using the prospective cohort study method. The data were collected from the nursing department students through face-to-face questionnaires. The sample of the study consisted of 186 nursing students. The data were obtained using a descriptive information form, which consists of questions regarding the descriptive characteristics of the nursing students, and the risky behaviors form, created by the researchers, to evaluate the effect of fasting during Ramadan on nursing students' risky behaviors. According to the findings of the research, it has been determined that the students who always fast during Ramadan have regular sahur. When the students' level of religious faith and fasting and having sahur status were compared with their risky behaviors, the mean scores of exercise and nutrition increased significantly, and the mean scores of interpersonal relationships decreased significantly. It was determined that the majority of students had a high level of religious faith, fasted and had sahur during Ramadan. Consequently, while Ramadan fasting negatively affected students' physical activity, nutrition and sleep patterns, it positively affected their interpersonal relationship status.

Digital Dietary Behaviors in Individuals With Depression: Real-World Behavioral Observation

BACKGROUND

Depression is often accompanied by changes in behavior, including dietary behaviors. The relationship between dietary behaviors and depression has been widely studied, yet previous research has relied on self-reported data which is subject to recall bias. Electronic device-based behavioral monitoring offers the potential for objective, real-time data collection of a large amount of continuous, long-term behavior data in naturalistic settings.

OBJECTIVE

The study aims to characterize digital dietary behaviors in depression, and to determine whether these behaviors could be used to detect depression.

METHODS

A total of 3310 students (2222 healthy controls [HCs], 916 with mild depression, and 172 with moderate-severe depression) were recruited for the study of their dietary behaviors via electronic records over a 1-month period, and depression severity was assessed in the middle of the month. The differences in dietary behaviors across the HCs, mild depression, and moderate-severe depression were determined by ANCOVA (analyses of covariance) with age, gender, BMI, and educational level as covariates. Multivariate logistic regression analyses were used to examine the association between dietary behaviors and depression severity. Support vector machine analysis was used to determine whether changes in dietary behaviors could detect mild and moderate-severe depression.

RESULTS

The study found that individuals with moderate-severe depression had more irregular eating patterns, more fluctuated feeding times, spent more money on dinner, less diverse food choices, as well as eating breakfast less frequently, and preferred to eat only lunch and dinner, compared with HCs. Moderate-severe depression was found to be negatively associated with the daily 3 regular meals pattern (breakfast-lunch-dinner pattern; OR 0.467, 95% CI 0.239-0.912), and mild depression was positively associated with daily lunch and dinner pattern (OR 1.460, 95% CI 1.016-2.100). These changes in digital dietary behaviors were able to detect mild and moderate-severe depression (accuracy=0.53, precision=0.60), with better accuracy for detecting moderate-severe depression (accuracy=0.67, precision=0.64).

CONCLUSIONS

This is the first study to develop a profile of changes in digital dietary behaviors in individuals with depression using real-world behavioral monitoring. The results suggest that digital markers may be a promising approach for detecting depression.

The Impact of Hot Ambient Temperature and Prolonged Fasting Duration during Ramadan on Patients with Chronic Kidney Disease: A Literature Review

The Islamic (lunar) calendar has 11 fewer days each year than the Gregorian (solar) calendar. Consequently, ambient temperatures during the month of Ramadan and the duration of the presunrise-to-sunset fast will change each year. At some point, individuals observing Ramadan will experience prolonged periods of fasting during the hot summer months. In this manuscript, findings published in the English-language medical literature that address the impact of prolonged fasting during the warmer summer months on patients with chronic kidney disease, including dialysis and transplantation patients, are reviewed. This is of particular concern given the accelerated pace of global warming. The limitations of the evidence that is currently available are also discussed, and an approach that might be used to standardize future evaluations of the impact of fasting on kidney health is suggested.

Quality of Sleep in the Saudi Population During the Holy Month of Ramadan

Background The holy month of Ramadan carries a massive change in a Muslim's lifestyle. During these 30 days of all-day fasting, people in Saudi Arabia prefer staying up all night and sleeping in the daytime, thus highly impacting their regular sleeping schedule, with a sizable effect on the quality of sleep. This study aimed to measure the quality of sleep and sleep hygiene practices in the Saudi population. Methodology This cross-sectional study was conducted among the Saudi population during the holy month of Ramadan. A self-administered questionnaire was sent to the targeted population using social media platforms. Our questionnaire included demographic data, the Sleep Quality Scale (SQS) to measure sleep quality, and the Sleep Hygiene Index (SHI) to measure sleep hygiene practices. Results Of the 386 participants, 71.2% were females, and 64.5% were single. The total mean SQS score was 35.8 (SD = 10.9) out of 84 points, while the total mean SHI score was 19.8 (SD = 8.61) out of 52 points. Overall, 63.5% of the respondents had poor sleep hygiene practices. Significant factors for increased SHI included being unmarried, a student, not the main provider in the family, not a parent, and earning less than 5,000 SAR per month while having more than six individuals in the family was a significant factor for increased SQS. Conclusions During the month of Ramadan, poor sleep quality and inadequate sleep hygiene practices were common among the Saudi population. A significant risk factor for poor sleep quality was having more than six individuals at home while being unmarried, a student, not being the family's main provider, and earning less than 5,000 SAR per month were the significant risk factors for poor sleep hygiene practices. Further research is needed to establish the effect of poor sleep quality and inadequate sleep hygiene practices during Ramadan fasting in our region.

Time-Restricted Eating and Its Metabolic Benefits

Newer management strategies are being evaluated to treat obesity, which continues to increase worldwide. After 12 h of fasting, the body switches from glucose to fat metabolism, regulating protein synthesis and autophagy. These cellular responses are central to the metabolic benefits of time-restricted eating (TRE), independent of calorie restriction and weight loss, and they have heightened interest in TRE regimens. Controversy remains, however, regarding the benefits of TRE regimens. We reviewed the current literature and concluded that TRE is equivalent to calorie restriction for weight loss and has positive effects for patients with diseases such as nonalcoholic fatty liver disease, cancer, and cardiovascular disease.

Stress during Home Confinement Is Associated with Eating Misalignment among Adults during COVID-19 Lockdown

BACKGROUND

The COVID-19 pandemic forced Saudi Arabia to implement several measures including mandatory home confinement, banning entry to many cities, and suspending religious activities. Studies have reported inconsistent findings of the effect of home confinement on lifestyle factors. This study aims to assess the psychological impact of COVID-19 during home confinement and explore its association with dietary habits and weight change.

METHODS

A cross-sectional study was conducted among Saudi adults using an online survey between May and June 2020. Data on dietary habits, sleep quality, and stress were collected.

RESULTS

A total of n = 503 participants responded. Of 254 analyzed, 87% were females, 49% were overweight/obese (body mass index (BMI) ≥ 25 kg/m2), and 79% were under lockdown for >40 days. In multiple linear regression, higher stress scores during confinement were associated with higher stress scores before confinement and poorer sleep quality. In multiple logistic regression, those who did not eat at the same time had higher stress scores compared to those who always ate at the same time, whereas consuming ≥three meals was associated with lower stress scores than consuming one-two meals. The odds of gaining weight during confinement were higher among married adults, those with lower sleep quality, and consuming ≥three meals.

CONCLUSIONS

Stress during home confinement was associated with eating misalignment and the number of meals consumed. Although this study was limited by its cross-sectional design and reliance on self-reported data, it provides valuable insights into the dietary habits and weight-gain associated factors that need to be further explored and addressed in any future restrictions for improved well-being.

The Effect of Ramadan Fasting on the Coping Strategies Used by Male Footballers Affiliated with the Tunisian First Professional League

This study aimed to discover coping strategies among professional male Tunisian footballers during the Ramadan 2021 fast. One hundred and eighty footballers who belong to twelve Tunisian professional clubs (age: 25.54 ± 4.41 years, weight: 77.19 ± 5.99 kg; height: 180.54 ± 7.28 cm; BMI: 23.67 ± 0.58) were tested during three sessions: one week before Ramadan, during the last week of Ramadan, and one week after Ramadan 2021. The footballers completed the Arabic version of the Inventory of Coping Strategies for Competitive Sport (ICSCS) scale in each session. Responses were recorded retrospectively one hour after a competition. The analysis of variance revealed a significant effect of Ramadan fasting on the adaptation profile of footballers (F = 3.51; p-value = 0.0001). Before and after Ramadan fasting, active coping dominates the adaptation profile of Tunisian professional footballers. During Ramadan, footballers use an irregular and unbalanced coping profile. The lifestyle change induced by the Ramadan fast significantly and negatively affected the adaptation profile of Tunisian professional footballers. Under the effect of the month of Ramadan, footballers developed a different coping profile from that of normal months.

Time-restricted eating alters the 24-hour profile of adipose tissue transcriptome in men with obesity

OBJECTIVE

Time-restricted eating (TRE) restores circadian rhythms in mice, but the evidence to support this in humans is limited. The objective of this study was to investigate the effects of TRE on 24-hour profiles of plasma metabolites, glucoregulatory hormones, and the subcutaneous adipose tissue (SAT) transcriptome in humans.

METHODS

Men (n = 15, age = 63 [4] years, BMI 30.5 [2.4] kg/m2 ) were recruited. A 35-hour metabolic ward stay was conducted at baseline and after 8 weeks of 10-hour TRE. Assessment included 24-hour profiles of plasma glucose, nonesterified fatty acid (NEFA), triglyceride, glucoregulatory hormones, and the SAT transcriptome. Dim light melatonin onset and cortisol area under the curve were calculated.

RESULTS

TRE did not alter dim light melatonin onset but reduced morning cortisol area under the curve. TRE altered 24-hour profiles of insulin, NEFA, triglyceride, and glucose-dependent insulinotropic peptide and increased transcripts of circadian locomotor output cycles protein kaput (CLOCK) and nuclear receptor subfamily 1 group D member 2 (NR1D2) and decreased period circadian regulator 1 (PER1) and nuclear receptor subfamily 1 group D member 1 (NR1D1) at 12:00 am. The rhythmicity of 450 genes was altered by TRE, which enriched in transcripts for transcription corepressor activity, DNA-binding transcription factor binding, regulation of chromatin organization, and small GTPase binding pathways. Weighted gene coexpression network analysis revealed eigengenes that were correlated with BMI, insulin, and NEFA.

CONCLUSIONS

TRE restored 24-hour profiles in hormones, metabolites, and genes controlling transcriptional regulation in SAT, which could underpin its metabolic health benefit.

Aspetar clinical guidelines: Ramadan fasting and exercise for healthy individuals

Healthy adult Muslims who practice Ramadan fasting (RF) follow strict religious rules regarding their lifestyle. RF influences several parameters, including nutrition, hydration, and sleep habits, and can potentially reduce physical performance. It seems that RF prevents athletes from training and participating in competitions, and prevents the general community from engaging in physical exercise. This places practicing Muslim athletes at a competitive disadvantage. Therefore, the goal of this guide was to provide practical recommendations, based on expert panel consensus, for healthy athletes and their support staff on how to adopt appropriate behavioral, social, and psychological strategies to cope with the changes and constraints resulting from RF. The recommendations developed in this guide are not limited to prescribing appropriate exercise during the month of Ramadan (ie; schedule, frequency, intensity, duration, type of exercise, and training load), but cover different aspects of lifestyle such as nutrition, hydration, and sleep, and address psychosocial and cognitive aspects related to RF. These recommendations are intended for healthy individuals. Patients with chronic illnesses should refer to their doctor to ensure an eventual safe practice.

Time-restricted feeding and cognitive function in sedentary and physically active elderly individuals: Ramadan diurnal intermittent fasting as a model

Objectives

This study aimed to investigate the effects of Ramadan diurnal intermittent fasting (RDIF) on cognitive performance, sleep quality, daytime sleepiness, and insomnia in physically active and sedentary elderly individuals.

Methods

A total of 58 participants (62.93 ± 3.99 years) were assigned to one of the following two groups: a sedentary group (control group) who observed Ramadan (n = 32) and a physically active group (n = 26) who continued to train while observing Ramadan. Participants were assessed 2 weeks before Ramadan and during the fourth week of Ramadan. On each occasion, participants completed a digital assessment of their cognitive performance and responded to the Pittsburgh sleep quality index (PSQI), the insomnia severity index (ISI) and the Epworth sleepiness scale (ESS) questionnaires to assess sleep parameters.

Results

Compared to before Ramadan, performance in executive function (p = 0.035), attention (p = 0.005), inhibition (p = 0.02), associative memory (p = 0.041), and recognition memory (p = 0.025) increased significantly during Ramadan in the physically active group. For the sedentary group, associative learning performance decreased (p = 0.041), whilst performances in the remaining domains remained unchanged during Ramadan. Global PSQI, ISI, and ESS scores indicated both groups suffered from poor sleep quality and excessive daytime sleepiness, with significantly higher negative effects of RDIF observed in the sedentary group.

Conclusion

Older adults who continue to train at least three times per week during Ramadan may improve their cognitive performance, despite the impairment of sleep quality. Future studies in older adults during Ramadan including objective measures of sleep (e.g., polysomnography, actigraphy) and brain function (e.g., functional magnetic resonance imaging) are warranted.

Determinants of natural adult sleep: An umbrella review

BACKGROUND

Sleep has a major impact on health, which makes it a relevant topic for research and health practitioners. Research on sleep determinants, i.e. factors that positively or negatively influence sleep, is fragmented.

OBJECTIVE

The purpose of this umbrella review is to provide an overview of the current evidence on determinants of natural adult sleep.

METHODS

A comprehensive literature search was performed on determinants of sleep. Reviews and meta-analyses on natural adult sleep were included. Six electronic databases (PubMed, WoS, Embase, CINAHL, PsycInfo and Cochrane) were used for the search, last accessed September 2021. The quality of the selected articles was assessed using the AMSTAR2 tool. Results were categorized in four main categories: biological, behavioral, environmental and personal/socio-economical determinants.

RESULTS

In total 93 reviews and meta-analyses resulted in a total of 30 identified determinants. The impact of each determinant differs per individual and per situation. Each determinant was found to affect different sleep parameters and the relationship with sleep is influenced by both generic and specific moderators.

DISCUSSION

A comprehensive overview on relevant sleep determinants provides a practical and scientifically based starting point to identify relevant intervention approaches to secure or improve individual sleep quality. The difference in aggregation level of the determinants and in measurement methods are the major limitations of this umbrella review. Extending existing generic sleep hygiene rules with an overview of all types of potential determinants will enhance the awareness of the complexity and can be used to improve the effect of sleep interventions in health promotion.

TRIAL REGISTRATION

The umbrella review was registered with PROSPERO (registration ID CRD42020149648) https://www.google.com/search?client=firefox-b-d&q=CRD42020149648.

Changes in dietary intake, chronotype and sleep pattern upon Ramadan among healthy adults in Jeddah, Saudi Arabia: A prospective study

Background

Notable lifestyle changes can occur in Ramadan due to the sudden shift in eating routine with fasting during daylight hours. This study aimed to examine the changes in dietary intakes, chronotype, sleep pattern, and physical activity level before and during Ramadan in healthy adults.

Methods

This study was conducted in Jeddah city, Saudi Arabia, and convenience sampling was used. To compare dietary, chronotype and sleep pattern changes before and during Ramadan, data were collected in two separate periods: the first period was 2 months before Ramadan, and the second period was during the last 3 weeks of Ramadan. Dietary intake was assessed using 24-h food recall and chronotype using Morningness-Eveningness Questionnaire. Daytime sleepiness and sleep duration were assessed using the Epworth sleepiness scale and a sleep diary for seven consecutive days, respectively. Anthropometric measurements were also taken across the study periods.

Results

A total of 115 adults (96 females and 19 males) were included in the study. Significant increases in daily calorie and carbohydrate intakes during Ramadan than before Ramadan were noted (calorie intake: 1,482.9 ± 536.4 kcal/day before Ramdan vs. 1,635.5 ± 635.1 kcal/day during Ramadan; carbohydrate intake: 180.8 ± 72.1 g/day before Ramadan vs. 202.6 ± 88.7 g/day during Ramadan; p < 0.05). Chronotypes and daytime sleepiness were also associated significantly with Ramadan fasting. A significant slight reduction in body weight during Ramadan was observed (66.4 ± 18.1 kg before Ramdan vs. 66.1 ± 17.8 kg before Ramadan and during Ramadan, respectively; p < 0.05).

Conclusion

This study indicates that Ramadan diurnal fasting was associated with greater calorie and carbohydrate intake, changes in chronotype, and daytime sleepiness. The study also suggests that Ramadan diurnal fasting model may be a promising weight loss strategy.

INTERmittent FASTing in people with insulin-treated type 2 diabetes mellitus - the INTERFAST-2 study protocol

AIM

Intermittent fasting, a dietary intervention of alternate eating and fasting, has gained popularity in people trying to lose weight. Intermittent fasting could provide an alternative to classic caloric restriction in people with type 2 diabetes mellitus. The aim of the study is to determine the impact of a 12-week intermittent fasting regimen compared with usual care in people with type 2 diabetes mellitus receiving insulin therapy.

METHODS

This open, single-centre, randomized controlled trial investigates participants with type 2 diabetes mellitus on insulin therapy and a glycated haemoglobin A1c (HbA1c) of ≥53 mmol/mol (≥7.0%) and a minimum insulin dose of 0.3 IU/kg body weight per day. Participants are randomized in a 1:1 ratio to either 12 weeks of intermittent fasting or the standard care group. All participants receive dietary counselling, continuous glucose monitoring, measurement of the resting metabolic rate, an oral glucose tolerance test, body composition measurement via dual-energy X-ray absorptiometry and stool samples for microbiome analyses at the beginning and at the end of the intervention. Two co-primary outcomes (analysed in hierarchical order) were chosen for the study: (i) the difference in the change of HbA1c from baseline to 12 weeks and (ii) the difference in the number of participants achieving a combined end point encompassing a body weight reduction of at least 2%, an insulin dose reduction of at least 10% and an absolute HbA1c reduction of at least 3 mmol/mol (0.3%) between the two groups.

Association of Ramadan Participation with Psychological Parameters: A Cross-Sectional Study during the COVID-19 Pandemic in Iran

COVID-19 restrictions are associated with poor physical-activity (PA). Less is known about the relationship between the combination of these restrictions with Ramadan intermittent fasting (RIF), PA, mental health, and sleep-quality. The present study aimed to evaluate whether COVID-19 restrictions and RIF during the fourth wave of the COVID-19 pandemic in Iran are associated with poor PA, anxiety, well-being, and sleep-quality outcomes. A total of 510 individuals participated in an online questionnaire that was disseminated to adults (≥18 years) residing in Iran from 13 May 2021 to 16 May 2021 (~3 days), just after the end of Ramadan 2021. PA behavior (Godin-Shephard Leisure-Time Exercise Questionnaire), anxiety (General Anxiety Disorder-7), well-being (Mental Health Continuum-Short Form), and sleep-quality (Pittsburgh Sleep Quality Index). Of 510 individuals included in the study (331 female (64.9%); mean ± SD, 31 ± 12 years), 172 (33.7%) reported less PA during the Ramadan 2021. PA was associated with better well-being and sleep-quality outcomes. Regardless of PA, participants who fasted for all of Ramadan had less anxiety and better well-being outcomes than those who fasted part of Ramadan or did not fast at all. However, the fasting part of Ramadan decreased the sleep-quality of active participants. The Ramadan 2021 was associated with poor PA, well-being, and sleep-quality of Iranians. However, PA was associated with better well-being and sleep-quality outcomes, and those who fasted all Ramadan had better anxiety and well-being outcomes. Therefore, PA during Ramadan might be an essential and scalable mental health resilience builder during COVID-19 restrictions which should be encouraged.

Effect of Intermittent Fasting (18/6) on Energy Expenditure, Nutritional Status, and Body Composition in Healthy Adults

Objective

This study was aimed at evaluating the effect of intermittent fasting of Ramadan on resting energy expenditure (REE), body composition, and nutritional status.

Methods

The study was conducted on a total of 27 adults (16 females, 11 males) who were fasting (18 h) in the Ramadan month (May 6–June 3) of 2019. REE was measured using the indirect calorimeter. Dietary energy and nutrient intakes were evaluated by 3-day food records in baseline and post-Ramadan. Body composition and some metabolic parameters were analyzed simultaneously with REE measurements. All measurements were performed two times at baseline, and post-Ramadan.

Results

Body weight (−2.9% vs. −1.4%), body mass index (BMI) (−3.1% vs. −2.1%), fat-free mass (−2.7% vs. −1.4%), and hydration status were decreased in both males and females after the Ramadan fasting (p < 0.05). REEs (kcal/d) of the participants were 1708.1 ± 262.50 kcal/d and 1596.5 ± 302.27 kcal/d at baseline and post-Ramadan, respectively (6.5%) (p < 0.05). This decrease in REE (kcal/d) in females was greater than that in males (−8.1% vs. −4.6%). However, no statistically significant difference was found in sleep duration (h), physical activity levels, dietary energy and nutrient intakes, and blood pressures (mm Hg) of both genders compared to baseline (p > 0.05).

Conclusion

Intermittent circadian fasting may lead to a decreased energy expenditure and a change in fat-free mass in healthy individuals, and this effect is interpreted as gender-dependent.

Does observance of Ramadan affect sleep in athletes and physically active individuals? A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to provide an accurate description of the effect of Ramadan observance on sleep duration, sleep quality, daily nap duration, and daytime sleepiness in athletes and physically active individuals. Five electronic databases (PubMed, Web of Science, Scopus, Wiley, and Taylor and Francis) were used to search for relevant studies conducted with athletes or physically active individuals during Ramadan, published in any language, and available before May 23, 2021. Studies that included assessments of sleep quantity and/or quality, and/or daytime sleepiness, and/or daily naps in athletes and physically active individuals were included. The methodological quality of the studies was assessed using "QualSyst". Of the 18 papers included in this study (298 participants in total), 14 were of strong quality, two were moderate, and the remaining two were rated as weak. Individuals who continued to train during Ramadan experienced a decrease in sleep duration (number of studies, K = 17, number of participants, N = 289, g = -0.766, 95% confidence interval [CI] -1.199 to -0.333, p = 0.001). Additionally, the global score of the Pittsburgh Sleep Quality Index increased from 4.053 (K = 5, N = 65, 95% CI 3.071-5.034) pre-Ramadan, to 5.346 (95% CI 4.362-6.333) during Ramadan, indicating a decrease in sleep quality. The duration of daytime naps increased during compared to pre-Ramadan (K = 2, N = 31, g = 1.020, 95% CI 0.595-1.445, p = 0.000), whereas Epworth Sleepiness Scale scores remained unchanged during versus pre-Ramadan (K = 3, N = 31, g = 0.190, 95% CI -0.139-0.519, p = 0.257). In conclusion, individuals who continued to train during Ramadan experienced a decrease in sleep duration, impairment of sleep quality, and increase in daytime nap duration, with no change in daytime sleepiness levels.

The effects of Ramadan intermittent fasting on liver function in healthy adults: A systematic review, meta-analysis, and meta-regression

INTRODUCTION

Growing evidence is suggestive that intermittent fasting likely to improve liver function; however, still the evidences are controversial to draw a definitive conclusion. Therefore, we conducted a systematic review and meta-analysis to estimate the effect size for changes in liver function tests (LFT) in healthy people practicing Ramadan diurnal intermittent fasting (RDIF), and to examine the impact of different covariates using subgroup analysis and meta-regression.

METHODS

Scientific databases were searched from date of inception in 1950 to the end of July 2020. The liver function tests searched and analyzed were aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin (BLU), L-lactate dehydrogenase (LDH) and prothrombin time (PT).

RESULTS

Twenty studies (601 adult participants in total, aged 18-57 years) conducted in 10 countries between 1987 and 2020 were identified. RDIF-induced effect sizes for the LFT expressed as standardized mean difference (SMD) [95% confidence interval] were: AST (no. of studies K = 16, number of subjects N = 502, SMD = -0.257 [-0.381, -0.133], I² = 42%); ALT (K = 16, N = 502, SMD = -0.105 [-0.282, 0.07], I² = 71%); GGT (K = 2, N = 46, SMD = -0.533 [-0.842, -0.224], I² = 0%); ALP (K = 10, N = 312, SMD = -0.318 [-0.432, -0.204], I² = 0.0%); BLU (K = 10, N = 325, SMD = -0.264 [-0.520, -0.007], I² = 70.1%); LDH (K = 5, N = 145, SMD = -0.041 [-0.380, 0.298], I² = 72%); PT (K = 2, N = 74, SMD = -0.027 [-0.732, 0.678], I² = 87%).

CONCLUSION

RDIF induces significant but small (AST, ALP, BLU) to medium (GGT) positive changes on LFT, and may confer a transient, short-term protection against fatty liver disease in healthy subjects.

The Window Matters: A Systematic Review of Time Restricted Eating Strategies in Relation to Cortisol and Melatonin Secretion

Time-Restricted Eating is an eating pattern based on the circadian rhythm which limits daily food intake (usually to ≤12 h/day), unique in that no overt restriction is imposed on the quality, nor quantity, of food intake. This paper aimed to examine the effects of two patterns of TRE, traditional TRE, and Ramadan fasting, on two markers of circadian rhythm, cortisol and melatonin. PubMed and Web of Science were searched up to December 2020 for studies examining the effects of time restricted eating on cortisol and melatonin. Fourteen studies met our inclusion criteria. All Ramadan papers found statistically significant decrease in melatonin (p < 0.05) during Ramadan. Two out of the three Ramadan papers noted an abolishing of the circadian rhythm of cortisol (p < 0.05). The non-Ramadan TRE papers did not examine melatonin, and cortisol changes were mixed. In studies comparing TRE to control diets, Stratton et al. found increased cortisol levels in the non-TRE fasting group (p = 0.0018) and McAllister et al. noted no difference. Dinner-skipping resulted in significantly reduced evening cortisol and non-significantly raised morning cortisol. Conversely, breakfast skipping resulted in significantly reduced morning cortisol. This blunting indicates a dysfunctional HPA axis, and may be associated with poor cardio-metabolic outcomes. There is a paucity of research examining the effects of TRE on cortisol and melatonin. The contrasting effect of dinner and breakfast-skipping should be further examined to ascertain whether timing the feeding window indeed has an impact on circadian rhythmicity.

Joint consensus statement of the Saudi Public Health Authority on the recommended amount of physical activity, sedentary behavior, and sleep duration for healthy Saudis: Background, methodology, and discussion

The Saudi Public Health Authority 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 Grading of Recommendations Assessment, Development, and Evaluation (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.

Sleep Quality and Performance in Professional Athletes Fasting during the Month of Ramadan

Background: Maintaining physical performance during Ramadan Diurnal Fasting (RDF) is a challenge for professional athletes. The literature shows that sleep disturbances experienced by athletes during RDF are associated with reduced physical performance. The effect of sleep quality on physical performance, and the effect of work status on physical performance during RDF among athletes, besides engaging in trainings, have been little investigated. This study aims to evaluate the effect of RDF on the physical performance of professional athletes taking into consideration their sleep quality and work status. Methods: Professional medium-distance male runners (n = 32) participated in our study in the summer of 2019. Data about socio-demographics, training characteristics, sleep quality (Pittsburg Sleep Quality Index: PSQI), physical performance (Cooper Test; Harvard step test) were collected before and during Ramadan. Student’s-test and Welch and Wilcoxon tests were used for data analysis. Results: Both quality of sleep and physical performance of athletes deteriorated during Ramadan. People with better quality of sleep had better physical fitness/performance both before and during RDF. Athletes who worked beside trainings achieved worse physical fitness test results and had worse quality of sleep. Conclusions: Policies aimed to improve physical performance in RDF should consider the quality of sleep and the work status of athletes.

Time-restricted feeding is associated with mental health in elderly Italian adults

In recent years, mental disorders have represented a relevant public health problem due to their deleterious effect on quality of life and the difficulty of timely diagnosis. The growing trends have been shown to be highly influenced by modern society, unhealthy lifestyle and harmful dietary habits. Not only the specific foods or dietary patterns have been hypothesized to play a role on mental health; also, temporal regulation of feeding and fasting has emerged as an innovative strategy to prevent and treat mental health disease. The aim of this cross-sectional study was to investigate the association between time-restricted feeding (TRF) and mental health outcomes including perceived stress, depressive symptoms, and sleep quality assessed in a cohort of southern Italian adults. Demographic and dietary characteristics of 1,572 adults living in southern Italy were analyzed. Food frequency questionnaires were used to calculate dietary intakes; participants were also asked what time, on average, they consumed their meals to calculate the eating window of time and identify those eating within 8 hours or less. Logistic regression analyses were performed to test the association between mental health outcomes. After adjusting for potential confounding factors, including adherence to the Mediterranean diet and having breakfast/dinner, no associations were found between TRF and mental health outcomes; however, when performing the analyses by age groups, individuals older than 70 years having a feeding time window of 8 hours were less likely to have signs of mental health distress [odds ratio (OR) = 0.14, 95% confidence interval (CI): 0.03-0.65] compared to those having no feeding time restriction independently of diet quality; notably, adjusting for having breakfast nullified the association (OR = 0.13, 95% CI: 0.02-1.18), while adjusting for having dinner did not change it (OR = 0.14, 95% CI: 0.03-0.67). No further associations were found for specific mental health outcomes explored separately. In conclusion, restricting the daily time feeding window is associated with lower signs of mental health distress in individuals older than 70 years. Albeit preliminary, these findings on elderly individuals require further investigation using prospective design and an amended approach to control for fasting.

Effects of Dinner Timing on Sleep Stage Distribution and EEG Power Spectrum in Healthy Volunteers

PURPOSE

Eating time and sleep habits are important modifiable behaviors that affect metabolic health, but the relationship between food intake and sleep remains incompletely understood. Observational data suggest that late food intake is associated with impaired sleep quality. We examined the effect of routine dinner (RD, 5 hours before bedtime) vs late dinner (LD, 1 hour before bedtime) on sleep architecture in healthy volunteers.

PARTICIPANTS AND METHODS

This was a post hoc analysis of a randomized crossover study of RD vs LD with a fixed sleep opportunity in a laboratory setting. On each of the two visits, 20 healthy adult volunteers (10 women) received an isocaloric meal followed by overnight polysomnography. Sleep architecture over the course of the night was assessed using visual sleep staging and EEG spectral power analysis and was compared between RD and LD. We modeled the proportions of spectral power in alpha, beta, delta, and theta bands as functions of dinner timing, time of night, and their interaction with mixed-effect spline regression.

RESULTS

Conventional sleep stages were similar between the 2 visits. LD caused a 2.5% initial increase in delta power and a reciprocal 2.7% decrease in combined alpha and beta power (p<0.0001). These effects diminished as sleep continued with a reversal of these patterns in the latter part of the night.

CONCLUSION

Contrary to the existing literature, shifting dinner timing from 5 hours before sleep to 1 hour before sleep in healthy volunteers did not result in significant adverse changes in overnight sleep architecture. In fact, LD was associated with deeper sleep in the beginning of the night and lighter sleep in the latter part of the night in healthy volunteers. This novel manifestation of postprandial hypersomnia may have therapeutic potential in patients with sleep disorders.

Research gaps in Ramadan fasting studies in health and disease

BACKGROUND AND AIM

Ramadan fasting is a religious fasting of Muslims and has many effects on health and disease. This study aim was to analyze Ramadan fasting research output during the past five years and identify research gaps in this field.

MATERIALS AND METHODS

A systematic search was performed in Web of Science, pubmed, Scopus, EMBASE and Cochrane databases by appropriate keywords. Documents published between January 2015 and January 2020 with English language were included. After removing duplicates, remained documents were screened and classified.

RESULTS

Finally, after screening, 393 documents remained and were classified. Of these documents, 53 were review article and 338 original articles. More than 96% of studies were clinical study while basic science studies were too limited. Among the study topics, diabetes mellitus with 31% was the most common topic followed by metabolic disorders and nutrition, respectively.

CONCLUSION

Ramadan fasting is an important religious issue that needs more attention. Research should be directed to clinical and basic studies in different health and disease conditions other than nutrition and metabolic disorders.

Time restricted feeding and mental health: a review of possible mechanisms on affective and cognitive disorders

In the last decades, a high increase in life expectancy not adequately balanced by an improvement in the quality of life has been observed, leading possibly to an increase in the prevalence of affective and cognitive disorders related to aging, such as depression, cognitive impairment, dementia and Alzheimer's disease. As mental illnesses have multifactorial aetiologies, many modifiable factors including lifestyle and nutrition play an essential role. Among nutritional factors, intermittent fasting has emerged as an innovative strategy to prevent and treat mental health disorders, sleep disturbances and cognitive impairment. Among all types of intermittent fasting regimens, the time restricted feeding appears to be the most promising protocol as it allows to induce benefits of a total fasting without reducing global calories and nutrients intake. This review summarises the evidence on the effect of time restricted feeding towards brain health, emphasising its role on brain signalling, neurogenesis and synaptic plasticity.

Self-Coping Strategies Among Jordanian Athletes During Ramadan Fasting: A Questionnaire Proposal

: This study aims to categorize the adaptation strategies of Muslim athletes who fast during Ramadan and proposes a self-coping strategy questionnaire as a complementary assessment tool. A total of 109 Jordanian Muslim athletes (mean age 20.0 ± 8.5 years) were surveyed by completing a self-coping questionnaire designed to classify an individual athlete’s level of adaptation. This study was conducted during the month of Ramadan 2019 and developed based on the training, nutritional, psychological, self-control, and recovery dimensions. Seventy percent of athletes found that they developed good or very good coping mechanisms. Coping strategies vary from one dimension to another, but in general, athletes often had a positive perceived coping. Athletes expressed that they are shifting the training hours with a preference for quality training rather than quantity and associated with a longer rest time. In addition, they were in favor of food hygiene associated with a strategy of sharing meals and providing water. The majority (59%) of the athletes said they were psychologically prepared for the potential effects of fasting. This research shows that athletes develop self-adjusting strategies to counter the effects of fasting. The questionnaire on the self-coping strategies provides important and precise information on the level of coping achieved by the athletes.

A systematic review, meta-analysis, and meta-regression of the impact of diurnal intermittent fasting during Ramadan on glucometabolic markers in healthy subjects

AIM

Studies on the effect of Ramadan diurnal intermittent fasting (RDIF) on glucometabolic markers have yielded conflicting results. We conducted ameta-analysis to estimate the effect size for changes in glucometabolic markers in healthy, non-athletic Muslims during Ramadan, and to assess the effect of variable covariates using meta-regression.

METHODS

CINAHL, Cochrane, EBSCOhost, EMBASE, Google Scholar, ProQuest Medical, PubMed/MEDLINE, ScienceDirect, Scopus, and Web of Science databases were searched from date of inceptionto January 2020. The glucometabolic markers analyzed were: fasting glucose (FG), insulin, insulin resistance (HOMA-IR), leptin, and adiponectin.

RESULTS

We identified seventy-two studies (3134 participants in total) that were conducted in 22 countries between 1982 and 2020. RDIF-induced effect sizes for the glucometabolic markers were: FG (no. of studies K = 61, number of subjects N = 2743, Hedges'g = -0.102, 95% CI: -0.194, -0.01); serum insulin (K = 16, N = 648, Hedges'g = 0.030 95% CI: -0.165, 0.226); HOMA-IR (K = 10, N = 349, Hedges'g = -0.012, 95% CI: -0.274, 0.250); leptin (K = 13, N = 442, Hedges'g = -0.010, 95% CI: -0.243, 0.223); and adiponectin (K = 11, N = 511, Hedges'g = 0.034, 95% CI: -0.227, 0.296).

CONCLUSION

RDIF imposes no adverse metabolic impacts, and might help in improving some glucometabolic markers in healthy subjects.

Food as a circadian time cue - evidence from human studies

Meal timing and composition are frequently reported in the literature as zeitgebers (that is, time cues) for the circadian system of humans and animal models, albeit secondary to light. Although widely assumed to be true, evidence for food zeitgeber effects specific to humans is notably scarce. Fostering zeitgeber hygiene in the general population as the development and practice of healthy use of zeitgebers could potentially reduce chronobiological strain, which is defined as disruption or misalignment within the circadian system. Such chronobiological strain is associated with modern 24/7 lifestyles (for example, shift work) and several negative health outcomes. Adjustments to meal timing and composition are an attractive strategy to synchronize circadian rhythms and develop zeitgeber hygiene. Thus, clarifying the actual effect of meal timing and composition on the human circadian system is a crucial piece of the human chronobiology puzzle. This Review weighs the evidence from human studies pertaining to the hypothesis that food is a circadian zeitgeber by comparing findings against formal zeitgeber criteria put forward by Jürgen Aschoff in the 1950s.

Bioavailability of Melatonin from Lentil Sprouts and Its Role in the Plasmatic Antioxidant Status in Rats

Melatonin is a multifunctional antioxidant neurohormone found in plant foods such as lentil sprouts. We aim to evaluate the effect of lentil sprout intake on the plasmatic levels of melatonin and metabolically related compounds (plasmatic serotonin and urinary 6-sulfatoxymelatonin), total phenolic compounds, and plasmatic antioxidant status, and compare it with synthetic melatonin. The germination of lentils increases the content of melatonin. However, the phenolic content diminished due to the loss of phenolic acids and flavan-3-ols. The flavonol content remained unaltered, being the main phenolic family in lentil sprouts, primarily composed of kaempferol glycosides. Sprague Dawley rats were used to investigate the pharmacokinetic profile of melatonin after oral administration of a lentil sprout extract and to evaluate plasma and urine melatonin and related biomarkers and antioxidant capacity. Melatonin showed maximum concentration (45.4 pg/mL) 90 min after lentil sprout administration. The plasmatic melatonin levels increased after lentil sprout intake (70%, p < 0.05) with respect to the control, 1.2-fold more than after synthetic melatonin ingestion. These increments correlated with urinary 6-sulfatoxymelatonin content (p < 0.05), a key biomarker of plasmatic melatonin. Nonetheless, the phenolic compound content did not exhibit any significant variation. Plasmatic antioxidant status increased in the antioxidant capacity upon both lentil sprout and synthetic melatonin administration. For the first time, we investigated the bioavailability of melatonin from lentil sprouts and its role in plasmatic antioxidant status. We concluded that their intake could increase melatonin plasmatic concentration and attenuate plasmatic oxidative stress.

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

In this article, we reviewed recent data that examined the relationship of circadian rhythm, mealtime, and intermittent fasting with the risk of cardiometabolic dysfunction. We also examined the effect of their interactions on cardiometabolic risks. Furthermore, since major differences exists between Ramadan diurnal intermittent fasting compared to other forms of experimental intermittent fasting, in this article, we further restricted the discussion to Ramadan diurnal intermittent fasting. PubMed and Google Scholar databases were searched using “intermittent fasting,” “time-restricted feeding,” “fasting,” “mealtime,” “circadian rhythm,” and “cardiometabolic risk,” focusing on human studies published after 2013. Recent evidence indicates that meal timing may influence circadian rhythm, as a result, it may also directly or indirectly impact cardiometabolic risk. In humans, several studies suggested that late mealtime is related to an increased risk of poor cardiometabolic health. Nevertheless, large clinical interventional studies are required to assess causality between late mealtime and cardiometabolic morbidity. Currently, evidence indicates that Ramadan diurnal intermittent fasting has several beneficial effects that may reduce the risk of cardiometabolic disorders, such as weight reduction, improvement in lipid profile and glycemic control, reduction in proinflammatory markers, and oxidative stress. Nevertheless, several changes in daily lifestyle routine, happening during the Ramadan month, may affect the all measured markers of cardiometabolic diseases. Summarily, no definitive conclusion about the impact of Ramadan intermittent fasting on oxidative stress can be formulated. Therefore, large, well-designed studies, which control for various confounding factors are required to assess the influence of Ramadan diurnal intermittent fasting on markers of cardiometabolic risk and disorders.

Effect of diurnal fasting on sleep during Ramadan: a systematic review and meta-analysis

PURPOSE

The current meta-analysis aimed to obtain a more stable estimate of the effect size of Ramadan diurnal intermittent fasting (RDF) on sleep duration and daytime sleepiness.

METHODS

Databases (Scopus, ScienceDirect, ProQuest Medical, PubMed/MEDLINE, Web of Science, EBSCOhost, Cochrane, CINAHL, and Google Scholar) were searched from database inception to the end of June 2019. The sleep quality measures analyzed were excessive daytime sleepiness (EDS) measured by the Epworth sleepiness scale (ESS) and total sleep time (TST). Subgroup analyses for age, sex, and levels of physical activity were conducted.

RESULTS

We identified 24 studies (involving 646 participants, median age 23.7 years, 73% men) conducted in 12 countries from 2001 to 2019. The results revealed that TST decreased from 7.2 h per night [95% confidence interval (CI) 6.7-7.8] before Ramadan to 6.4 h (95% CI 5.3-7.5) during Ramadan, while the ESS score increased slightly from 6.1 (95% CI 4.5-7.7) before Ramadan to 7.0 (95% CI 5.2-8.8) during Ramadan. Effect sizes on sleep quality measures during RDF demonstrated a moderate reduction in TST (number of studies, K = 22; number of subjects, N = 571, Hedges' g value of -0.43, 95% CI - 0.64 to -0.22, Q = 90, τ² = 0.15, I² = 78%, P < 0.001), while ESS score showed negligible effect on EDS (K = 9, N = 362, Hedges' g value of -0.06, 95% CI -0.43 to 0.28, Q = 21, τ² = 0.13, I² = 76%, P value = 0.001).

CONCLUSION

During the month of Ramadan, there is approximately a 1 hour reduction in TST and nearly a 1 point increase in the ESS score.

The effects of diurnal intermittent fasting on proinflammatory cytokine levels while controlling for sleep/wake pattern, meal composition and energy expenditure

Purpose

This study aimed to assess the effect of diurnal intermittent fasting (DIF) during and outside of the month of Ramadan on plasma levels of interleukin (IL)-1β, IL-6, and IL-8, while controlling for sleep/wake pattern, sleep length and quality, meal composition, energy consumption and expenditure, and light exposure. DIF outside of the month of Ramadan was performed to evaluate the effect of DIF in the absence of the way of life accompanying Ramadan.

Methods

Twelve healthy male volunteers with a mean age of 25.1 ± 2.5 years arrived to the sleep laboratory on 4 times: 1) adaptation, 5 weeks before Ramadan; 2) 4 weeks before Ramadan while performing DIF for 1 week (fasting outside of Ramadan; FOR); 3) 1 week before Ramadan (non-fasting baseline; non-fasting BL); and 4) After completing 2 weeks of Ramadan while performing DIF. Plasma levels of cytokines were assessed using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00.

Results

During DIF, there was a significant decrease in the levels of cytokines, particularly, IL-1β and IL-6, in most measurements compared to non-fasting BL. This reduction was more obvious during the FOR period. There were no significant changes in the circadian phase of the measured cytokines reflected by the acrophase of the measured variables during fasting (FOR and Ramadan) compared to non-fasting BL.

Conclusion

Under controlled conditions, DIF led to significantly decreased plasma levels of cytokines (IL-1β, IL-6, and IL-8), particularly IL-1β and IL-6 across 24 h. DIF had no effect on the circadian patterns of the measured cytokines as shown by cosinor analysis.

The Impact of Ramadan Fasting on the Reduction of PASI Score, in Moderate-To-Severe Psoriatic Patients: A Real-Life Multicenter Study

Fasting during the month of Ramadan consists of alternate abstinence and re-feeding periods (circadian or intermittent fasting). Nothing is currently known on the impact of this kind of fasting on psoriasis. A sample of 108 moderate-to-severe plaque psoriasis patients (aged 42.84 ± 13.61 years, 62 males, 46 females) volunteered to take part in the study. A significant decrease in the “Psoriasis Area and Severity Index” (PASI) score after the Ramadan fasting (mean difference = −0.89 ± 1.21, p < 0.0001) was found. At the multivariate regression, the use of cyclosporine (p = 0.0003), interleukin-17 or IL-17 blockers (p < 0.0001), and tumor necrosis factor or TNF blockers (p = 0.0107) was independently associated with a low PASI score, while the use of apremilast (p = 0.0009), and phototherapy (p = 0.0015) was associated with a high PASI score before the Ramadan fasting. Similarly, the consumption of cyclosporine (p < 0.0001), IL-17 blockers (p < 0.0001), mammalian target of rapamycin or mTOR inhibitors (p = 0.0081), and TNF blockers (p = 0.0017) predicted a low PASI score after the Ramadan fasting. By contrast, narrow band ultraviolet light B or NB-UVB (p = 0.0015) was associated with a high PASI score after Ramadan fasting. Disease duration (p = 0.0078), use of apremilast (p = 0.0005), and of mTOR inhibitors (p = 0.0034) were independent predictors of the reduction in the PASI score after the Ramadan fasting. These findings reflect the influence of dieting strategy, the biological clock, and circadian rhythm on the treatment of plaque psoriasis.