Health impact of fasting in Saudi Arabia during Ramadan: association with disturbed circadian rhythm and metabolic and sleeping patterns

Effectiveness of an intermittent fasting diet versus regular diet on fat loss in overweight and obese middle-aged and elderly people without metabolic disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

As the number of adults aged over 40 with obesity increases dramatically, intermittent fasting interventions (IF) may help them to lose fat and weight. This systematic review investigated the most recent research on the effects of intermittent fasting and a regular diet on body composition and lipids in adults aged over 40 with obesity without the metabolic disease.

DATA SOURCES

Randomized controlled trials (RCTs) on IF on adults aged over 40 with obesity were retrieved from PubMed, Web of Science, EBSCO, China Knowledge Network (CNKI), VIP database, Wanfang database with the experimental group using IF and the control group using a regular diet. Revman was used for meta-analysis. Effect sizes are expressed as weighted mean differences (WMD) and 95% confidence intervals (CI).

STUDY SELECTION

A total of 9 articles of randomised controlled trials that met the requirements were screened for inclusion. Studies typically lasted 2-6 weeks. The experimental population was aged 42-66 years, with a BMI range of 25.7-35 kg/m2.

SYNTHESIS

A total of 9 RCTs were included. meta-analysis showed that body weight (MD: -2.05 kg; 95% CI (-3.84, -0.27); p = 0.02), BMI (MD: -0.73 kg/m2; 95% CI (-1.05, -0.41); p < 0.001), fat mass (MD: -2.14 kg; 95% CI (-3.81, 0.47); p = 0.01), and TG (MD = -0.32 mmol/L, 95% CI (-0.50, -0.15, p < 0.001) were significantly lower in the experimental group than in the control group. No significant reduction in lean body mass (MD: -0.31 kg; 95% CI (-0.96, 0.34); p = 0.35).

CONCLUSION

IF had a reduction in body weight, BMI, fat mass, and TG in adults aged over 40 with obesity without metabolic disease compared to RD, and IF did not cause a significant decrease in lean body mass, which suggests healthy and effective fat loss. However, more long-term and high-quality trials are needed to reach definitive conclusions.

Various types of fasting diet and possible benefits in nonalcoholic fatty liver: Mechanism of actions and literature update

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury, affecting around one-fourth of the general population across the world. Several important pathophysiological mechanisms underlying NAFLD include oxidative stress, inflammation, liver fibrosis, and apoptosis. Currently, therapeutic approaches are not ideal for managing NAFLD, thus new approaches and treatments are still needed. Over the last two decades, various fasting protocols have been explored to reduce body weight and improve metabolic disorders. In this review, we provide updated literature that supports fasting regimens for subjects with NAFLD and describes underlying mechanisms of action. We suggest that fasting regimens may modulate NAFLD via several mechanisms, including changes in gut microbiota, hepatic arginase, hepatic autophagy, inflammatory responses, liver functional enzymes and hepatic steatosis, fibroblast growth factors signaling, white adipose tissue browning, adipokines, circadian rhythms, lipid profiles, and body composition.

Glucagon-Like Peptide-1 (GLP-1) during Ramadan: Narrative Review of the Published Literature

Ramadan fasting, a religious practice observed by Muslims worldwide, involves abstaining from eating, drinking, smoking, and using oral medications from dawn to dusk during the ninth lunar month. Studies have demonstrated that fasting during Ramadan has been shown to increase HDL cholesterol, leptin, adiponectin, and insulin sensitivity, as well as lower several hemostatic risk factors for cardiovascular diseases. Additionally, it may result in a drop in blood sugar levels, especially in diabetics who are also on blood sugar-lowering medicine. Hypoglycemia, characterized by low blood sugar levels, could also result from fasting during Ramadan. The GLP-1 (glucagon-like peptide-1) hormone plays a significant role in regulating glucose metabolism and insulin secretion, and Ramadan fasting can affect its production and release in the gut. Research contributes to our understanding of the utilization of GL-1 medications during Ramadan among patients, broadening therapy alternatives and offering insightful information for well-informed decision-making. Therefore, this narrative review aims to explore the current evidence that studies the safety and efficacy of GLP-1 agonists during Ramadan for nondiabetic and diabetic patients to ensure healthy fasting during Ramadan.

A circadian rhythm-restricted diet regulates autophagy to improve cognitive function and prolong lifespan

Diet and circadian rhythms have been found to have a profound impact on health, disease, and aging. Skipping breakfast, eating late, and overeating have adverse effects on the body's metabolism and increase the risk of cardiovascular and metabolic diseases. Disturbance of circadian rhythms has been associated with increased risk of atherosclerosis, Alzheimer's disease, Parkinson's disease, and other diseases. Abnormal deposition of amyloid β (Aβ) and tau proteins in the brain and impaired synaptic function are linked to cognitive dysfunction. A restrictive diet following the circadian rhythm can affect the metabolism of lipids, glucose, and amino acids such as branched chain amino acids and cysteine. These metabolic changes contribute to autophagy through molecular mechanisms such as adenosine monophosphate-activated protein kinase (AMPK), rapamycin (mTOR), D-β-hydroxybutyrate (D-BHB), and neuropeptide Y (NPY). Autophagy, in turn, promotes the removal of abnormally deposited proteins and damaged organelles and improves cognitive function, ultimately prolonging lifespan. In addition, a diet restricted to the circadian rhythm induces increased expression of brain-derived neurotrophic factor (BDNF) in the forebrain region, regulating autophagy and increasing synaptic plasticity, thus enhancing cognitive function. Consequently, circadian rhythm-restricted diets could serve as a promising non-pharmacological treatment for preventing and improving cognitive dysfunction and prolonging lifespan.

Ramadan Fasting and Short-Term Maximal Physical Performance: Searching for Optimal Timing of the Last Meal "Suhoor" in Female Pre-University Handball Players

Aiming to identify the ideal suhoor timing for maintaining optimal physical performance and health indicators during Ramadan intermittent fasting, the present study compares the effects of early vs. late Suhoor on short-term high-intensity physical exercise while controlling the body mass index (BMI) oral temperature (OT), dietary intake, and sleep patterns. In a randomized design, 19 female pre-university handball players (age: 16.8 ± 0.4 y; height: 1.70 ± 0.9 m; and body mass: 61.5 ± 6.9 kg) underwent two test sessions (at 08:00 a.m. and 05:00 p.m.) at four different conditions: ten days prior to Ramadan (R - 10), the final ten days of Ramadan (R) including both Early Suhoor R(ES) and Late Suhoor R(LS) conditions, and the ten days immediately following Ramadan (R + 10). A recovery period of at least 48 h has been set between successive test sessions at each period. Outcome measures included the Countermovement Jumps Test (CMJ), Modified Agility t-Test (MATT), Repeated Sprint Ability (RSA), and Rating of Perceived Exertion (RPE). The Pittsburgh Sleep Quality Index (PSQI), OT, BMI, and daily diary intake were assessed across the three periods. The total scores of PSQI decreased significantly during R and R + 10 compared to R - 10. When performed in the afternoon, CMJ, MATT, and RSA performance decreased significantly at R(ES) and R(LS) conditions compared to R - 10. However, these performances decreased only after R(ES) when performed in the morning. Furthermore, performances were lower during R(ES) compared to R(LS) in the afternoon for all tests and the morning for MATT and RSA tests. These findings support prior research showing a deterioration of physical performance during Ramadan fasting and indicate a more pronounced impact following early Suhoor condition. Therefore, consuming a late suhoor, closer to pre-dawn time, could be suggested as an effective strategy to minimize physical performance decline during short-term high-intensity exercise.

Pre-Exercise Caffeine Intake Attenuates the Negative Effects of Ramadan Fasting on Several Aspects of High-Intensity Short-Term Maximal Performances in Adolescent Female Handball Players

The aim of this investigation was to determine whether, after Ramadan, pre-exercise caffeine intake can reduce any possible negative effects of this month on short-term maximal performances in young female handball players. A randomized study involved thirteen young female handball players. Participants performed a squat jump (SJ), Illinois agility test (AG), and 5 m run shuttles test (total (TD) and peak (PD) distances) at 08:00 AM and 06:00 PM on three different occasions: one week before Ramadan (Pre-R), the last week of Ramadan (R), and the week after Ramadan (Post-R). A placebo (Pla) or caffeine (Caff) (6 mg·kg-1) was administered 60 min before exercise test sessions at two distinct times of day (08:00 AM and 06:00 PM) during the two periods: Pre and Post-R. The PSQI and dietary intake were assessed during all testing periods. The results revealed that Pre-R, (SJ, AG, TD, and PD) test performances were greater in the evening (PM) than in the morning (AM) (all p < 0.001). However, compared with Pre-R, PM performances declined significantly during R (all p < 0.001) and Post-R (p < 0.05, p < 0.01, p < 0.01 and p < 0.001, respectively). In addition, Pre-R, AM Caff produced moderate significant improvements compared with AM Pla, with small-to-no beneficial effects observed with PM Caff in SJ (4.8% vs. 1%), AG (1.8% vs. 0.8%), TD (2.8% vs. 0.3%), and PD (6% vs. 0.9%). Nevertheless, Caff produced moderate ergogenic effects during both AM and PM sessions during Post-R in SJ (4.4% vs. 2.4%), AG (1.7% vs. 1.5%), TD (2.9% vs. 1.3%), and PD (5.8% vs. 3%) with values approaching those of Pre-R Pla within the same time of day (p > 0.05, p > 0.05, p < 0.05, and p < 0.05, respectively). In summary, pre-exercise Caff intake with a dose equivalent to 6 mg·kg-1 reduced the negative effects of Ramadan fasting in several aspects of short-term maximal performances in young female handball players at both times of the day.

Timing of Resistance Training During Ramadan Fasting and Its Effects on Muscle Strength and Hypertrophy

PURPOSE

During Ramadan month, Muslims often continue training to maintain their muscle performance. However, trainers should stress the importance of the time of day chosen for practicing resistance training (RT) during Ramadan fasting to avoid health and performance alteration. Thus, this study aimed to investigate the effects of the timing of RT during Ramadan intermittent fasting (RIF) on muscle strength and hypertrophy in healthy male adults.

METHODS

Forty men were randomly allocated to 2 matched groups: 20 practicing whole-body RT in the late afternoon in a fasted state and 20 training in the late evening in a fed state (FED). Both groups performed 4 days per week of whole-body RT (∼75%-85% 1-repetition maximum, 12 repetitions/3-4 sets) during RIF. Anthropometric measurements and 1-repetition-maximum test for the squats, deadlift, and bench press were measured. A cross-sectional area of the quadriceps and biceps brachii was examined using ultrasound scans. All measurements were taken at 4 time points: 24 hours before the start of Ramadan, on the 15th day of Ramadan, on the 29th day of Ramadan, and 21 days after Ramadan.

RESULTS

Post hoc tests indicated significant preimprovement to postimprovement in FED at the 29th day of Ramadan for the 1-repetition-maximum test for the squats (P = .02; effect size = 0.21) and deadlift (P = .03; effect size = 0.24) when compared to 24 hours before the start of Ramadan. No significant changes were observed in the fasted-state group or for cross-sectional area for both groups.

CONCLUSIONS

Practicing RT during RIF appears not to have adverse effects on muscle hypertrophy and strength no matter whether it is practiced in FED or fasted state. However, RT had greater effects on muscle strength when applied in FED. Our findings suggest that training sessions should be scheduled after breaking the fast during Ramadan.

Implications of Ramadan Fasting in the Setting of Gastrointestinal Disorders

Intermittent fasting is an increasingly popular dieting technique with many well-studied benefits, such as permitting weight loss in obese patients, lowering low-density lipoprotein cholesterol (LDL-C) levels and triglyceride levels, and optimizing circadian rhythms. A special type of intermittent fasting occurs during Ramadan, when Muslims worldwide fast daily from dawn to sunset for a month. Ramadan fasting has demonstrated several health benefits, including improving the gut microbiome, modifying gut hormone levels, and lowering proinflammatory markers such as cytokines and blood lipids. Although fasting has many health benefits, fasting during Ramadan may aggravate chronic medical conditions. We aim to review the literature devoted to Ramadan fasting and its effects on Muslim patients with gastrointestinal (GI) disorders, such as Inflammatory bowel disease (IBD), peptic ulcer disease (PUD), upper GI bleeding (UGIB), gastroesophageal reflux disease (GERD), and liver conditions. We will discuss recommendations for diet and medication compliance during Ramadan in the recommended pre-Ramadan counseling sessions. In this study, we used PubMed to research journals using the key terms "Ramadan," "intermittent fasting," and "gastrointestinal diseases." The current literature studying the impact of Ramadan on gastrointestinal disorders shows that patients with IBD have a minimal risk of disease exacerbation, although older men with ulcerative colitis (UC) were more prone to exacerbation during fasting. Patients with duodenal ulcers were at a higher risk of hemorrhage after Ramadan fasting. Although with mixed results, studies show patients with liver disease demonstrated improvements in liver enzymes, cholesterol, and bilirubin after Ramadan. Physicians should offer pre-Ramadan counseling to educate patients on the risks of fasting and encourage shared decision-making. To facilitate more definitive discussions between the physician and a Muslim patient, clinicians should seek a deeper understanding of how Ramadan fasting affects certain health conditions and offer accommodations, such as diet and medication adjustments.

The Health-Promoting Effects and the Mechanism of Intermittent Fasting

Intermittent fasting (IF) is an eating pattern in which individuals go extended periods with little or no energy intake after consuming regular food in intervening periods. IF has several health-promoting effects. It can effectively reduce weight, fasting insulin levels, and blood glucose levels. It can also increase the antitumor activity of medicines and cause improvement in the case of neurological diseases, such as memory deficit, to achieve enhanced metabolic function and prolonged longevity. Additionally, IF activates several biological pathways to induce autophagy, encourages cell renewal, prevents cancer cells from multiplying and spreading, and delays senescence. However, IF has specific adverse effects and limitations when it comes to people of a particular age and gender. Hence, a more systematic study on the health-promoting effects and safety of IF is needed. This article reviewed the research on the health-promoting effects of IF, providing a theoretical basis, direction for subsequent basic research, and information related to the clinical application of IF.

Ramadan Fasting and its Health Benefits: What’s New?

Fasting is one of the five pillars of Islam. Fasting entails more than abstaining from food and drink, fasting improves impulse control and aids in the development of good behavior. The holy month of Ramadan falls on the 9th month of the lunar calendar. Ramadan is a month-long fasting period that takes place between dawn and sunset. Some people with diabetes and those who are sick or have certain medical conditions may be exempt. The majority of people with diabetes, on the other hand, choose to fast; even against medical advice. Many studies have been conducted to determine the health benefits of fasting. Apart from the benefits to the body’s organs, Ramadan fasting is also beneficial for the growth of the gut microbiota and gene expression and is believed to impact the body’s autophagy process. Furthermore, Ramadan fasting has an impact on mental health; TC and LDL were lower, while HDL and TG were higher, lowers inflammation, and oxidative stress markers.

Diabetes and Ramadan: Practical guidelines 2021

Fasting during Ramadan is one of the five pillars of Islam and is obligatory for all healthy Muslims from the age of puberty. Though individuals with some illness and serious medical conditions, including some people with diabetes, can be exempted from fasting, many will fast anyway. It is of paramount importance that people with diabetes that fast are given the appropriate guidance and receive proper care. The International Diabetes Federation (IDF) and Diabetes and Ramadan (DaR) International Alliance have come together to provide a substantial update to the previous guidelines. This update includes key information on fasting during Ramadan with type 1 diabetes, the management of diabetes in people of elderly ages and pregnant women, the effects of Ramadan on one's mental wellbeing, changes to the risk of macrovascular and microvascular complications, and areas of future research. The IDF-DAR Diabetes and Ramadan Practical Guidelines 2021 seek to improve upon the awareness, knowledge and management of diabetes during Ramadan, and to provide real-world recommendations to health professionals and the people with diabetes who choose to fast.

Ramadan and gestational diabetes: maternal and neonatal outcomes

AIMS

The impact of Ramadan exposure to Gestational Diabetes Mellitus (GDM) pregnancies is not known. We therefore aimed to assess the association of Ramadan with maternal and neonatal outcomes among pregnant women with GDM.

METHODS

Retrospective cohort study of 345 Muslim women with singleton pregnancies who attended a major Sydney teaching hospital during the period 1989-2010, was undertaken. Exposure to Ramadan was stratified by the: (1) total pregnancy days exposed to Ramadan, (2) duration (hours) of daily fasting and (3) trimester of exposure. Maternal and neonatal outcomes were examined by exposure status, and never exposed pregnancies were comparator in all three analyses. Fasting status was not recorded.

RESULTS

We found no significant effect of Ramadan exposure on mean birthweight, macrosomia and maternal outcomes. However, we found a significant trend for increased neonatal hyperbilirubinemia with increasing Ramadan days exposure and later trimester exposure (p_trend ≤ 0.02 for both), with adjusted OR 3.9 (p=0.03) for those with ≥ 21 days exposure to Ramadan and adjusted OR 4.3 (p=0.04) for third trimester exposure. Conversely longer Ramadan exposure and late trimester exposure were independently associated with a lower prevalence of neonatal hypoglycaemia (adjusted OR 0.4 and 0.3 for ≥ 21 days and third trimester exposure, respectively). Furthermore, neonatal hypoglycaemia decreased for the fasting period of > 15 h group (adjusted OR 0.2, p = 0.01).

CONCLUSIONS

Ramadan exposure is associated with reduced neonatal hypoglycaemia, with no effect on birthweight, implying more favourable glycaemic control. However, the fourfold excess of neonatal hyperbilirubinemia indicates a need for further study of Ramadan and GDM.

Ramadan and Diabetes: What About Non-Fasting Patients with Diabetes?

BACKGROUND

The management of diabetes during Ramadan is well codified. International guidelines recommend avoiding fasting for patients with the risk of complications. However, during Ramadan drastic changes occur in lifestyles habits. Our study aims to evaluate the impact of the month of Ramadan on the lifestyle habits and metabolic profile of non-fasting patients with diabetes.

PATIENTS AND METHODS

This observational cross-sectional study was carried out during 3 months of Ramadan in 2018, Ramadan 2019, and Ramadan 2021. We conducted 3 consultations (before, during, and after Ramadan). Before Ramadan, we collected anthropometric and metabolic parameters, and we assessed physical activity level and dietary intake. During Ramadan, we evaluated the occurrence of complications such as hyperglycemia and hypoglycemia, as well as we assessed physical activity level, dietary intake, and the number of meals. After Ramadan re-evaluate anthropometric and metabolic parameters.

RESULTS

We included 155 patients, 93.5% had type 2 diabetes and 6.5% had type 1 diabetes. We found that glycated hemoglobin, LDL cholesterol, and Triglyceride increased significantly after Ramadan (p-value <0.001). We also found that weight, body mass index, waist circumference. Caloric intake increased significantly during Ramadan (p-value <0.001); this increase concerned 61.3% of patients. In terms of metabolic parameters, diabetes was unbalanced in 52.6% of patients, hypoglycemia occurs in 20.9% of patients, and hyperglycemia was experienced by 37% of patients during Ramadan. We found that LDL cholesterol increased in 48.4% of patients, triglycerides increased in 60.6% of patients and serum level of total cholesterol increased in 55% of patients.

CONCLUSION

Our study showed that during Ramadan risk of complications in patients with diabetes is not only related to fasting.

[Ramadan fasting during treatment with external beam radiotherapy]

INTRODUCTION

Many Muslim cancer patients insist on fasting during the month of Ramadan, even during treatment. The purpose of this observational study is to study the practice of fasting, in patients receiving external radiation therapy.

METHODS

Our study was conducted during the month of Ramadan 1441 (2018) in the radiotherapy department of Ibn Rochd University Hospital of Casablanca. We included all patients who received external radiotherapy during this period. We thus collected the characteristics of patients, disease and treatment modalities. After an interview, with a pre-established questionnaire, we were able to establish the observance of the fast.

RESULTS

We collected a total of 209 patients. The most frequently represented locations were breast cancer followed by gynecological cancers in 35.4% and 18.7% respectively. All our patients were fasting Ramadan before the diagnosis of cancer, however, only 39.2% were fasting during the treatment by radiotherapy, and just 40% of patients have discussed the possibility of fasting with their oncologist. In multivariate analysis, the stage of the disease was the only factor related to the fasting status of our patients.

DISCUSSION

Even under treatment, many of our patients fast during the month of Ramadan. Further studies are needed to evaluate the tolerance of fasting in order to better answer the question "can I fast?".

Time-Restricted Feeding and Aerobic Performance in Elite Runners: Ramadan Fasting as a Model

A distance runner's performance is generally limited by energy availability when competing or training. Modifying meal frequency and timing by abstaining from eating or drinking, from dawn to dusk, during Ramadan fasting is hypothesized to induce hypohydration and reduced caloric and nutrient intake. The purpose of this study was to investigate the impact of Ramadan fasting on runners' performances. Fifteen trained male distance runners who observed Ramadan participated in this study (Age = 23.9 ± 3.1 years; Peak VO₂ = 71.1 ± 3.4 ml/kg/min). Each participant reported to the human performance lab on two testing occasions (pre-Ramadan and the last week of Ramadan). In each visit, participants performed a graded exercise test on the treadmill (Conconi protocol) and their VO₂, Heart Rate, time to exhaustion, RPE, and running speed were recorded. Detailed anthropometrics, food records, and exercise logs were kept for the entire period of the study. Repeated measure ANOVA, paired t-test, and Cohen's effect size analysis were carried out. Results indicated no significant influence for Ramadan fasting on body mass (p = 0.201), body fat (p = 0.488), lean body mass (p = 0.525), VO₂max (p = 0.960), energy availability (p = 0.137), and protein intake (p = 0.124). However, carbohydrate (p = 0.026), lipid (p = 0.009), water (p < 0.001), and caloric intakes (p = 0.002) were significantly reduced during Ramadan Fasting. Daily training duration (p < 0.001) and exercise energy expenditure (p = 0.001) were also reduced after Ramadan. Time to exhaustion (p = 0.049), and maximal running speed (p = 0.048) were improved. Overall, time to exhaustion and maximal running speed of the distance runners was improved during Ramadan fasting, independent of changes in nutrients intake observed during the current study. With proper modulation of training, distance runners performance can be maintained or even slightly improved following the month of Ramadan fasting.

Religious Fasting of Muslim Patients After Metabolic and Bariatric Surgery: a Modified Delphi Consensus

BACKGROUND

Fasting during Ramadan is one of the five pillars of the Muslim faith. Despite the positive effects of fasting on health, there are no guidelines or clear recommendations regarding fasting after metabolic/bariatric surgery (MBS). The current study reports the result of a modified Delphi consensus among expert metabolic/bariatric surgeons with experience in managing patients who fast after MBS.

METHODS

A committee of 61 well-known metabolic and bariatric surgeons from 24 countries was created to participate in the Delphi consensus. The committee voted on 45 statements regarding recommendations and controversies around fasting after MBS. An agreement/disagreement ≥ of 70.0% was regarded as consensus.

RESULTS

The experts reached a consensus on 40 out of 45 statements after two rounds of voting. One hundred percent of the experts believed that fasting needs special nutritional support in patients who underwent MBS. The decision regarding fasting must be coordinated among the surgeon, the nutritionist and the patient. At any time after MBS, 96.7% advised stopping fasting in the presence of persistent symptoms of intolerance. Seventy percent of the experts recommended delaying fasting after MBS for 6 to 12 months after combined and malabsorptive procedures according to the patient's situation and surgeon's experience, and 90.1% felt that proton pump inhibitors should be continued in patients who start fasting less than 6 months after MBS. There was consensus that fasting may help in weight loss, improvement/remission of non-alcoholic fatty liver disease, dyslipidemia, hypertension and type 2 diabetes mellitus among 88.5%, 90.2%, 88.5%, 85.2% and 85.2% of experts, respectively.

CONCLUSION

Experts voted and reached a consensus on 40 statements covering various aspects of fasting after MBS.

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.

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.

Effects of Ramadan intermittent fasting on leptin and adiponectin: a systematic review and meta-analysis

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 RESULTS

Data 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.

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.

Ramadan and Diabetes: A Narrative Review and Practice Update

Fasting in the Islamic month of Ramadan is obligatory for all sane, healthy adult Muslims. The length of the day varies significantly in temperate regions-typically lasting ≥ 18 h during peak summer in the UK. The synodic nature of the Islamic calendar means that Ramadan migrates across all four seasons over an approximately 33-year cycle. Despite valid exemptions, there is an intense desire to fast during this month, even among those who are considered to be at high risk, including many individuals with diabetes mellitus. In this review we explore the current scientific and clinical evidence on fasting in patients with diabetes mellitus, focussing on type 2 diabetes mellitus and type 1 diabetes mellitus, with brief reviews on pregnancy, pancreatic diabetes, bariatric surgery, the elderly population and current practice guidelines. We also make recommendations on the management of diabetes patients during the month of Ramadan. Many patients admit to a do-it-yourself approach to diabetes mellitus management during Ramadan, largely due to an under-appreciation of the risks and implications of the rigors of fasting on their health. Part of the issue may also lie with a healthcare professional's perceived inability to grasp the religious sensitivities of Muslims in relation to disease management. Thus, the pre-Ramadan assessment is crucial to ensure a safe Ramadan experience. Diabetes patients can be risk-stratified from low, medium to high or very high risk during the pre-Ramadan assessment and counselled accordingly. Those who are assessed to be at high to very high risk are advised not to fast. The current COVID-19 pandemic upgrades those in the high-risk category to very high risk; hence a significant number of diabetes patients may fall under the penumbra of the 'not to fast' advisory. We recognize that fasting is a personal choice and if a person chooses to fast despite advice to the contrary, he/she should be adequately supported and monitored closely during Ramadan and for a brief period thereafter. Current advancements in insulin delivery and glucose monitoring technologies are useful adjuncts to strategies for supporting type 1 diabetes patients considered to be high risk as well as 'high-risk' type 2 patients manage their diabetes during Ramadan. Although there is a lack of formal trial data, there is sufficient evidence across the different classes of therapeutic hypoglycaemic agents in terms of safety and efficacy to enable informed decision-making and provide a breadth of therapeutic options for the patient and the healthcare professional, even if the professional advice is to abstain. Thus, Ramadan provides an excellent opportunity for patient engagement to discuss important aspects of management, to improve control in the short term during Ramadan and to help the observants understand that the metabolic gains achieved during Ramadan are also sustainable in the other months of the year by maintaining a dietary and behavioural discipline. The application of this understanding can potentially prevent long-term complications.

Ramadan Intermittent Fasting Affects Adipokines and Leptin/Adiponectin Ratio in Type 2 Diabetes Mellitus and Their First-Degree Relatives

Background

In view of the association of Ramadan intermittent fasting with profound changes in lifestyle both in nondiabetic and diabetic patients, the aim of this study was to investigate the effect of Ramadan fasting on adiponectin, leptin and leptin to adiponectin ratio (LAR), growth hormone (GH), human-sensitive C-reactive protein (hs-CRP), and diabetic and metabolic syndrome factors in patients with Type 2 Diabetes Mellitus (Type 2 DM), their first-degree relatives (FDRs), and healthy controls.

Methods

This cohort study involved 98 Yemeni male subjects aged 30-70 years old: 30 Type 2 DM, 37 FDRs of Type 2 diabetic patients, and 31 healthy control subjects. Subjects' body mass index (BMI), waist circumference (WC), and blood pressure (BP) were measured, and venous blood samples were collected twice: the first samples were collected a couple of days prior to Ramadan fasting (baseline) and the second samples after 3 weeks of fasting.

Results

Ramadan fasting did not affect BMI, WC, and BP in Type 2 DM and their FDRs with respect to the baseline levels prior to Ramadan, whereas triglyceride and cholesterol were borderline significantly decreased in Type 2 DM with no effect in FDRs. Fasting blood glucose was not affected in Type 2 DM but was significantly increased in FDRs and control groups, whereas glycated haemoglobin (HbA1c) was slightly decreased in Type 2 DM, FDRs, and healthy controls. C-peptide, insulin, and insulin resistance (HOMA-IR) were significantly increased in Type 2 DM and FDRs, with no effect in the control group, whereas β-cell function (HOMA-β) was significantly decreased in FDRs and controls with no change in Type 2 DM. Ramadan fasting significantly decreased GH in both FDRs and control groups, and significantly increased hs-CRP in the control with no effect in Type 2 DM and FDRs. Adiponectin was significantly decreased, and leptin and LAR were significantly increased in Type 2 DM, FDRs, and control groups.

Conclusion

Ramadan intermittent fasting decreased adiponectin and increased leptin, LAR, insulin, and insulin resistance in both Type 2 DM and FDRs as well as decreased GH in both FDRs and healthy controls and increased hs-CRP in healthy controls. Moreover, Ramadan intermittent fasting neither worsens a patient's glycemic parameters nor improves it, with the exception of a slight improvement in HbA1c in Type 2 DM, FDRs, and healthy controls.

Intermittent Fasting and Metabolic Health: From Religious Fast to Time-Restricted Feeding

Over the past 10 to 15 years, intermittent fasting has emerged as an unconventional approach to reduce body weight and improve metabolic health beyond simple calorie restriction. In this review, we summarize findings related to Ramadan and Sunnah fasting. We then discuss the role of caloric restriction not only as an intervention for weight control, but importantly, as a strategy for healthy aging and longevity. Finally, we review the four most common intermittent fasting (IF) strategies used to date for weight management and to improve cardiometabolic health. Weight loss is common after IF but does not appear to be different than daily caloric restriction when compared directly. IF may also provide additional cardiometabolic benefit, such as insulin sensitization, that is independent from weight loss. While no specific fasting regimen stands out as superior at this time, there is indeed heterogeneity in responses to these different IF diets. This suggests that one dietary regimen may not be ideally suited for every individual. Future studies should consider strategies for tailoring dietary prescriptions, including IF, based on advanced phenotyping and genotyping prior to diet initiation.

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.

Impact of Ramadan on Physical Activity and Sleeping Patterns in Individuals with Type 2 Diabetes: The First Study Using Fitbit Device

INTRODUCTION

The impact of Ramadan fasting, a type of intermittent fasting, on the management of diabetes has not been well investigated. Physical activity, sleep duration, and time of sleep are susceptible to alterations during Ramadan due to the changes in the times and numbers of meals. This study compared physical activity and sleep patterns of individuals with type 2 diabetes mellitus (T2DM) during and after Ramadan using the international physical activity questionnaire (IPAQ) and a Fitbit Flex 2 accelerometer.

METHODS

Saudi individuals (n = 36) with T2DM completed a self-reported questionnaire and wore a Fitbit device for seven consecutive days during and after Ramadan. Fitbit generated weekly step counts, activity intensities, sedentary time, and sleep durations and times. IPAQ was used to estimate the physical activity and sitting time of participants in each period. Sleep patterns were assessed in each period by a self-reported questionnaire.

RESULTS

Both Fitbit and IPAQ indicated a high prevalence of low physical activity among the participants with non-significant variances between the during and after Ramadan periods. Also, a significant short daily total sleeping hours and daily night-time sleeping hours was seen during the Ramadan period. The duration of night-time sleep was observed to be low in each period.

CONCLUSIONS

This is the first study to use a Fitbit device to monitor individuals with T2DM who chose to fast during Ramadan. The study shows a high prevalence of low physical activity among Saudi individuals with T2DM in each period, and short sleep durations in the during Ramadan period compared to after Ramadan period. A high prevalence of short night-time sleep duration and excessive daytime sleeping was observed in both periods and significantly in the during Ramadan period. A larger study is needed in the future covering before, during, and after Ramadan to evaluate the impact of lifestyle changes related to Ramadan fasting on type 2 diabetes.

Effects of transcranial direct current stimulation over frontal, parietal and cerebellar cortex for cognitive function during fasting in healthy adults

Background

Transcranial direct current stimulation (tDCS) is a neuromodulation tool used to modify the cognitive function in subjects. There is a paucity of data on tDCS' effect on cognitive function during Ramadan fasting. This paper aims to assess the effect of tDCS of three brain areas, including the right dorsolateral prefrontal cortex (DLPFC), posterior parietal cortex (PPC), and cerebellum on cognitive function, and obtain safety data in healthy adults during Ramadan fasting.

Methods and material

A total of 42 healthy, right-handed participants were randomly assigned to one of the 6 stimulation groups: active (anodal)-tDCS of right DLPFC, PPC, and cerebellum; or sham for DLPFC, PPC, and cerebellum after 8 h of fasting for Ramadan. Safety data and cognitive function, such as attention-switching tasks (AST), were obtained by employing the Cambridge Neuropsychological Test Automated Battery (CANTAB) before and after each tDCS session. The cognitive function outcome variables were the response time and the percentage of correct answers in AST. For sham stimulation, the placement of the electrodes was the same as for the active stimulation.

Results

An improvement in performance time in attention tasks was observed; however, it did not reach a significant level after anodal stimulation of the DLPFC, PPC, and cerebellum. Overall, there were no statistically significant differences between the active and sham tDCS groups in cognitive function. There were no significant side effects of tDCS during fasting for any group.

Conclusions

Our data suggest that there are variable effects of tDCS on attention tasks during Ramadan fasting. TDCS appears to be safe, well-tolerated and adhered to the international standard of safety in the local population during Ramadan fasting. Further large sample size studies should be conducted to validate the current study findings and reach better conclusions.

Recommendations for management of diabetes during Ramadan: update 2020, applying the principles of the ADA/EASD consensus

Fasting the Holy month of Ramadan constitutes one of the five pillars of the Muslim faith. Although there is some evidence that intermittent fasting during Ramadan may be of benefit in losing weight and cardiometabolic risk factors, there is no strong evidence these benefits apply to people with diabetes. The American Diabetes Association/European Association for the Study of Diabetes consensus recommendations emphasize the importance of patient factors and comorbidities when choosing diabetes medications including the presence of comorbidities, atherosclerotic cardiovascular disease, heart failure, chronic kidney disease, hypoglycemia risk, weight issues and costs. Structured education and pre-Ramadan counseing are key components to successful management of patients with diabetes. These should cover important aspects like glycemic targets, self-monitoring of blood glucose, diet, physical activity including Taraweeh prayers, medication and dose adjustment, side effects and when to break the fast. The decision cycle adapted for the specific situation of Ramadan provides an aid for such an assessment. Children with type 1 diabetes should strongly be advised not to fast due to the high risk of acute complications such as hypoglycemia and probably diabetic ketoacidosis (DKA), although there is very little evidence that DKA is increased in Ramadan. Pregnant women with diabetes or gestational diabetes should be advised to avoid fasting because of possible negative maternal and fetal outcomes. Hypoglycemia is a common concern during Ramadan fasting. To prevent hypoglycemic and hyperglycemic events, we recommend the adoption of diabetes self-management education and support principles. The use of the emerging technology and continuous glucose monitoring during Ramadan could help to recognize hypoglycemic and hyperglycemic complications related to omission and/or medication adjustment during fasting; however, the cost represents a significant barrier.

Intermittent Fasting for Twelve Weeks Leads to Increases in Fat Mass and Hyperinsulinemia in Young Female Wistar Rats

Fasting is known to cause physiological changes in the endocrine pancreas, including decreased insulin secretion and increased reactive oxygen species (ROS) production. However, there is no consensus about the long-term effects of intermittent fasting (IF), which can involve up to 24 hours of fasting interspersed with normal feeding days. In the present study, we analyzed the effects of alternate-day IF for 12 weeks in a developing and healthy organism. Female 30-day-old Wistar rats were randomly divided into two groups: control, with free access to standard rodent chow; and IF, subjected to 24-hour fasts intercalated with 24-hours of free access to the same chow. Alternate-day IF decreased weight gain and food intake. Surprisingly, IF also elevated plasma insulin concentrations, both at baseline and after glucose administration collected during oGTT. After 12 weeks of dietary intervention, pancreatic islets displayed increased ROS production and apoptosis. Despite their lower body weight, IF animals had increased fat reserves and decreased muscle mass. Taken together, these findings suggest that alternate-day IF promote β -cell dysfunction, especially in developing animals. More long-term research is necessary to define the best IF protocol to reduce side effects.

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.

The effect of Ramadan fasting on cardiovascular events and risk factors in patients with type 2 diabetes: A systematic review

Ramadan is the fasting month in Islam. Muslims around the world observe Ramadan every year, including people with diabetes. Data on the association of fasting in people with diabetes are sparse. The purpose of this study is to assess the association of fasting on cardiovascular risk factors and events in people with diabetes. A comprehensive search was conducted in the following database: Embase, Medline, Cochrane library and CINAHL. The following key terms were used: Ramadan, Ramazan, Ramadhan, Muslim, Islam and fasting. Studies were eligible if they included people with Type 2 diabetes who fasted during Ramadan and reporting results on cardiovascular risk factors or events. Overall 22 studies met inclusion criteria for the review; five studies reported cardiovascular outcomes and 17 reported changes in risk factors. There is insufficient evidence to link Ramadan fasting with increased or reduced incidence of cardiovascular events in people with diabetes, though there were some indication stroke risk may be increased. Findings were inconsistent in term of risk factors as some favoured Ramadan and others did not.‬‬‬‬.

Recurrent circadian fasting (RCF) improves blood pressure, biomarkers of cardiometabolic risk and regulates inflammation in men

Background

The effects of fasting on health in non-human models have been widely publicised for a long time and emerging evidence support the idea that these effects can be applicable to human practice.

Methods

In an open label longitudinal follow-up, a cohort of 78 adult men (aged 20 to 85 years) who fasted for 29 consecutive days from sunrise to sunset (16 h fasting—referred to as recurrent circadian fasting) in Pakistan, were studied. The primary outcomes of the fasting study was weight loss/recovery and the associated changes in blood pressure and circulating levels of surrogate markers linked to organ and system functions—including cardiovascular, metabolic and inflammation. Post-fasting outcomes include the regulation of physiological biomarkers.

Results

Recurrent circadian fasting with weight loss reduced blood pressure (140.6 vs. 124.2 mmHg) and markers of cardiovascular risk (~ 4-fold for resistin; triglycerides: p < 0.0001). Reduced glycemia (p < 0.0001) and the associated changes in the regulation of ketosis (β-hydroxybutyrate) were accompanied by a metabolic shift (PPARβ, osteoprotegerin), suggesting the involvement of the different physiological systems tested. Elevated orexin-A levels (p = 0.0183) in participants indicate sleep disturbance and circadian adaptation. All participants had CRP level < 2 mg/l during the fasting period and a similar trend was observed for TNFα. While most SASP molecules were decreased after the fasting period, heightened levels of IL-8 and IL-6 suggest that some inflammatory markers may be elevated by recurrent circadian fasting. Importantly, older adults reveal similar or more substantial benefits from fasting.

Conclusions

Recurrent circadian fasting is beneficial at the cardiometabolic and inflammatory levels, especially for at-risk individuals—this is contingent on compliance towards the recommended dietary behaviour, which controls carbohydrate and caloric intake. These benefits from fasting may be particularly beneficial to older adults as they often exhibit abnormal cardiovascular, metabolic and inflammatory signatures.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2007-z) contains supplementary material, which is available to authorized users.

Effect of Ramadan diurnal fasting on visceral adiposity and serum adipokines in overweight and obese individuals

AIM

Excessive visceral adiposity is a major risk factor for developing insulin resistance and systemic low-grade inflammation. Ramadan diurnal fasting (RDF) is a religious ritual practiced by more than one billion Muslim throughout the world. It has been considered as one of the most common types of complementary and integrative health practices. The aim of this study is to examine the impact of RDF on visceral adiposity, circulating adipokines and glucoregulatory markers in patients with overweight or obesity.

METHODS

Overweight and obese subjects (n = 61; 23 men and 38 women) were included in the study. Body weight, visceral fat tissue area (measured by 3D-MRI), glucoregulatory factors, serum adipokines concentrations, dietary intake, and physical activity were assessed one week before and at the end of the lunar month of Ramadan.

RESULTS

From baseline, body weight and visceral fat tissue area serum total cholesterol, triglycerides, HDL-cholesterol, and systolic blood pressure significantly decreased (P < 0.05 for each) at the end of Ramadan. The serum levels of adiponectin, IL-6, TNF-α, and IGF-1 significantly decreased (P < 0.05 for each), but serum visfatin, leptin, apelin, IL-10, and IL-10/IL-6 ratio significantly increased (P < 0.05 for each) at the end of Ramadan. Changes in visceral adiposity significantly correlated with changes in plasma glucose (r = 0.4, P < 0.5) and resistin (r = 0.44, P < 0.001) at the end of Ramadan.

CONCLUSION

RDF lowers visceral adiposity, body weight and variably affects adipokines without adversely affecting markers of glucose homeostasis in individuals with overweight or obesity.

The role of inflammatory markers following Ramadan Fasting

Objectives:

The aim of present study was to investigate the effect of fasting during Ramadan on plasma adiponectin and TNF-α levels.

Methods:

This is a cross sectional study, conducted at Federal Urdu University of Arts, Science & Technology (FUUAST), Karachi, comprising a total of 55 (50%) females and 55 (50%) males whose ages ranged between 20 and 40 years, and fasted during Ramadan (June-July 2014) were enrolled in the study. Subjects were separated into normal weight, overweight and obese males and females. Anthropometric measurements and Fasting venous blood samples were taken at first and last (29^th) day of Ramadan. Plasma adiponectin and TNF-alpha levels were assayed with ELISA kits. All values were calculated and presented as mean ± standard error of the mean (SEM) and by using analysis of variance (ANOVA) for repeated measures. P values < 0.05 were accepted as significant.

Results:

Body mass index (BMI) (Kg/m2) in over-weight and obese male subjects exhibited considerable reduction (P<0.05; P<0.05), post Ramadan when compared to their respective pre Ramadan fasting weights. Noticeable and significant reduction was also observed in BMI of obese females (P<0.05). Post Ramadan Overweight Males (P<0.05) and Post Ramadan Obese Males (P<0.001) exhibited significantly elevated plasma adiponectin (μg/mL) values. While plasma adiponectin mean concentration of only obese females were significantly improved at last week of Ramadan (P<0.01). Fasting in Ramadan significantly decreased TNF-α (pg/mL) levels of post obese males and females than Pre-Ramadan-groups (P<0.05; P<0.01) respectively.

Conclusion:

The study reports of noticeable changes with Ramadan fasting resulting increase of plasma adiponectin and decrease of TNF-α levels as well as body weight. The study strongly suggests further investigations on larger sample sizes with possible association of dietary restrictions and weight loss on mechanism of enhanced adiponectin and reduced TNF-α in obese and overweight persons who fast on Ramadan pattern.

Intermittent Fasting During Ramadan Improves Insulin Sensitivity and Anthropometric Parameters in Healthy Young Muslim Men

The current study aimed to determine the effect of fasting during Ramadan on the metabolic profile, anthropometry, and serum leptin and adiponectin concentrations. Anthropometry and blood samples were examined at 2 phases: baseline (within 3 days of the start of the Ramadan fast) and end-line (in the last 3 days before the end of the Ramadan fast) in 27 healthy Muslim male participants who completed Ramadan fasting. Results demonstrate reductions in body weight (P < .001), body mass index (P < .001), fat mass (P = .003), muscle mass (P = .004), and waist circumference (P < .001) following reductions in energy intake (P = .003). Insulin sensitivity was improved. Serum insulin concentration and homeostatic model assessment of insulin resistance decreased significantly (P = .005 and P = .009). No significant change in fasting plasma glucose was observed. Correlation coefficients showed a significant correlation between the percentage changes in body weight and percentage changes in serum leptin concentration (r = 0.412; P = .037). These results demonstrate that intermittent fasting during Ramadan leads to beneficial effects by improving insulin sensitivity. It also resulted in a beneficial effect on weight and fat loss.

Decreased anxiety after Dawood fasting in the pre-elderly and elderly

Background A high prevalence of anxiety in the elderly often leads to decreased quality of life (QOL). A restrictive diet can increase the production of ketone bodies that encourage mood enhancement, neural protection and pain reduction. This study aimed to identify whether Dawood fasting could increase the QOL of the elderly by reducing anxiety. Methods This research was a quasi-experimental study involving a pretest-post-test control group design. The subjects were pre-elderly and elderly or healthy people aged more than 50, and a consecutive sampling method was employed. The fasting group observed the fast of Dawood, in which they abstained from eating, drinking, or having sexual intercourse from the break of dawn to dusk with the expressed intent to fast every other day. The fast was observed for 22 days (11 fasting days). Anxiety was examined using the Hamilton Rating Scale for Anxiety (HRS-A), while QOL was identified using the Indonesian version of the World Health Organisation Quality of Life (WHOQOL). Results A total of 48 respondents participated in this study with 24 respondents observing the fast of Dawood and 24 others not fasting. Results showed that the 22 days of Dawood fast reduced respondents' complaints about anxiety by 4.37% and was significantly different from the non-fasting group (p=0.001). There was an increase in the QOL of the fasting group (p=0.019), although no significant difference was found when compared to the non-fasting group. Conclusions The fast of Dawood reduced anxiety in the pre-elderly and elderly.

Ramadan fasting alters food patterns, dietary diversity and body weight among Ghanaian adolescents

BACKGROUND

Ramadan is a monthlong fast for healthy adolescents and adult Muslims. The quality of foods eaten and eating patterns in Ramadan may be different from other months of the year. Food intake of adolescents is a concern as energy and nutrient requirements are higher and needed to support the growth spurt of this stage. The objective of the present study was to describe the food patterns, dietary diversity and body weight changes among adolescents during Ramadan.

METHODS

A prospective cohort study design with four measurement points (baseline, midline, endline and post endline) was conducted among 366 adolescents in Junior High Schools. Food pattern was assessed with a food frequency questionnaire, a 24-h dietary recall was used to assess dietary diversity and body weight was measured using an electronic scale. A repeated measures ANOVA was used to compare changes in dietary diversity scores (DDS) and weight of pupils.

RESULTS

Half of the pupils (50.3%) were female and average age was 15.9 ± 1.8 years. Pupils fasted for an average of 28.3 ± 4.0 days and 14.3 ± 0.5 h a day (dawn to dusk) during Ramadan. The number and types of dishes taken at meal times differed substantially between Ramadan periods and outside Ramadan. Consumption of vitamin A-rich fruits, other fruits, and milk and milk products increased markedly during Ramadan. However, fasting came with a reduction in consumption of foods from roots and tubers, legumes and nuts, and dark green leafy vegetables while other food groups remained unchanged. Mean DDS increased significantly during Ramadan (F (2.933, 1070.573) = 7.152, p < 0.001) while mean daily meal frequency decreased (F (2.936, 1071.623) = 51.653, p < 0.001). There was significant body weight loss (-1.5 kg (95% CI: -1.1 kg to -1.6 kg)) among adolescents (F (2.656, 958.95) = 304.90, p < 0.001). Weight loss was short-lived; regained one month after Ramadan.

CONCLUSION

In this prospective cohort study among schooling Ghanaian adolescents who fast during Ramadan, fasting was characterised by marked changes in usual food patterns, increased dietary diversity and significant body weight loss.

The Effect of Ramadan Fasting on Biochemical Parameters in Healthy Thai Subjects

Introduction

Although, the effect of Ramadan fasting on the risks for Cardiovascular Disease (CVD) has been reported in several studies, the results were inconsistent. In addition, the effect of Ramadan fasting on biochemical parameters in Thai subjects has not been evaluated.

Aim

The aim of this study was to investigate the effect of Ramadan fasting on anthropometry, blood pressure, Fasting Blood Glucose (FBG), lipid profiles, and body composition in healthy Thai subjects.

Materials and Methods

A total of 65 healthy subjects (21 men and 44 women) aged between 19-24 years were randomly recruited. Anthropometry, blood pressure, FBG, Total Cholesterol (TC), Triglyceride (TG), High Density Lipoprotein-Cholesterol (HDL-C), Low Density Lipoprotein-Cholesterol (LDL-C), and body composition were measured before Ramadan, end of Ramadan and after one month of Ramadan.

Results

There were no changes in anthropometry, blood pressure, lipid profiles and body composition in both genders before Ramadan, end of Ramadan and after one month of Ramadan. Nevertheless, FBG levels were significantly increased after one month of Ramadan compared with baseline (5.09±0.50 versus 4.83±0.38 mmol/L, p=0.016, respectively) in women.

Conclusion

The Ramadan fasting did not affect the lipid, anthropometric and body composition in healthy Thai subjects. However, the increased FBG levels after one month of Ramadan were observed in women. To improve the favourable biochemical parameters after Ramadan fasting, the lifestyle modifications such as, increased intake of healthy diets and increased physical activity should be recommended.

Impact of Time-Restricted Feeding and Dawn-to-Sunset Fasting on Circadian Rhythm, Obesity, Metabolic Syndrome, and Nonalcoholic Fatty Liver Disease

Obesity now affects millions of people and places them at risk of developing metabolic syndrome, nonalcoholic fatty liver disease (NAFLD), and even hepatocellular carcinoma. This rapidly emerging epidemic has led to a search for cost-effective methods to prevent the metabolic syndrome and NAFLD as well as the progression of NAFLD to cirrhosis and hepatocellular carcinoma. In murine models, time-restricted feeding resets the hepatic circadian clock and enhances transcription of key metabolic regulators of glucose and lipid homeostasis. Studies of the effect of dawn-to-sunset Ramadan fasting, which is akin to time-restricted feeding model, have also identified significant improvement in body mass index, serum lipid profiles, and oxidative stress parameters. Based on the findings of studies conducted on human subjects, dawn-to-sunset fasting has the potential to be a cost-effective intervention for obesity, metabolic syndrome, and NAFLD.

Ramadan fasting in Saudi Arabia is associated with altered expression of CLOCK, DUSP and IL-1alpha genes, as well as changes in cardiometabolic risk factors

BACKGROUND

During the fasting month of Ramadan, practicing Saudis develop severe disturbances in sleeping and feeding patterns. Concomitantly, cortisol circadian rhythm is abolished, diurnal cortisol levels are elevated and circulating levels of several adipokines are altered favouring insulin resistance.

AIM

To examine changes in the expression of CLOCK and glucocorticoid-controlled genes, such as DUSP1 and IL-1α in Saudi adults before and during Ramadan, and to investigate possible associations with selected cardiometabolic risk factors.

METHODS

Healthy young volunteers (5 females, 18 males; mean age +SEM = 23.2 +1.2 years) were evaluated before Ramadan and two weeks into it. Blood samples were collected at 9 am (±1 hour) and twelve hours later for determination of serum lipid profile, high sensitivity CRP (hsCRP), and adiponectin. The expression of CLOCK, DUSP1 and IL-1α was evaluated in circulating leukocytes.

RESULTS

Mean levels of GGT and morning adiponectin decreased, while those of LDL-c/ HDL-c and atherogenic index (AI) increased significantly in Ramadan compared to Shabaan. There was no significant difference between morning and evening adiponectin during Ramadan, while the diurnal rhythm of hsCRP was lost. CLOCK gene expression mean was significantly higher in morning than in evening during Shabaan. Mean morning and evening DUSP1 mRNA levels showed significant increase during Ramadan compared to Shabaan, however, its diurnal rhythm was maintained. Morning IL-1α mRNA expression remained significantly higher than in the evening during Ramadan, but was markedly decreased compared to Shabaan.

DISCUSSION

Ramadan fasting in Saudi Arabia is associated with improvements in some cardiometabolic risk factors, such as circulating GGT and hsCRP and leukocyte expression of IL-1α mRNA, suggesting that intermittent fasting might have a beneficial component. These benefits may be offset by the previously reported dysregulation in the circadian rhythm, excess glucocorticoid levels and action, and insulin resistance, explaining increased prevalence of cardiometabolic disorders and type 2 diabetes mellitus.

The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report

AIMS:

We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin.

METHODS:

Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m² reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2^nd week of Ramadan while fasting (Ramadan). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory.

RESULTS:

The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels.

CONCLUSIONS:

In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin.

Ramadan model of intermittent fasting for 28 d had no major effect on body composition, glucose metabolism, or cognitive functions in healthy lean men

OBJECTIVES

There has been a parallel increase in the incidence of obesity and diabetes as well as the number of daily meals. However, evidence is lacking regarding the role of intermittent fasting. The aim of this study was to determine the effects of a Ramadan model of intermittent fasting (RIF; 14 h of daytime abstinence from food and drinking) for 28 d on body composition, glucose metabolism, and cognitive function.

METHODS

Ten healthy, lean men were included in a nonrandomized, crossover, intervention study. Testing was performed before a control period of 28 d, as well as before and after 28 d of RIF. Whole-body dual-energy x-ray absorptiometry, magnetic resonance imaging of the abdomen, fitness test, oral glucose tolerance test, and cognitive function tests were performed. As secondary outcome, the participants' physical activity and 72-h glycemic responses were monitored 6 d within each of the periods. Dietary intake, appetite, and mood questionnaires also were assessed.

RESULTS

Comparing Δ differences from testing days; body mass index changes from the control period (Δ mean: 0.2 kg/m², 95% confidence interval [CI], -2 to 0.5) and the RIF period (Δ mean: -0.3 kg/m², 95% CI, -0.6 to -0.1) were significantly different (P < 0.05). Secondary outcomes within the RIF period showed an increased area under curve (AUC) for hunger accompanied by a reduced AUC for satiety (both, P < 0.05), less mean steps per day (P < 0.05), and less positive feelings in the afternoon (P < 0.01) compared with the control period. No changes were observed in any of the other evaluated parameters.

CONCLUSIONS

Free-living participants were able to comply with 14 h of daily daytime abstinence from food and drinking for 28 d with only a minor effect on body mass index and without any effects on body composition, glucose metabolism, and cognitive function.

Effect of Ramadan fasting in Saudi Arabia on serum bone profile and immunoglobulins

BACKGROUND

Each year Muslims fast from dawn to sunset for 1 month (Ramadan). In Saudi Arabia, the sleep-wake cycle during Ramadan is severely disturbed and is associated with abolition of the circadian cortisol rhythm, exposing Saudis to continuously increased cortisol levels, which may influence the immune response. In addition to cortisol, sleep and fasting affect the secretion of parathyroid hormone (PTH) and hence bone metabolism.

METHODS

Our objective was to investigate the effect of Ramadan type fasting on secretory patterns of PTH, markers of bone metabolism, and serum immunoglobulins. Blood samples from healthy young volunteers were collected at 9 a.m. and 9 p.m. (± 1 hour) before (Shaban) and 2 weeks into Ramadan. Calcium, phosphorus, magnesium, albumin, alkaline phosphatase, 25-OH vitamin D, intact PTH (iPTH), and immunoglobulin (Ig) A, M and G were measured.

RESULTS

During Ramadan, evening-adjusted calcium was higher (p = 0.036) and phosphate lower (p < 0.001) than the corresponding morning value. Moreover, the Ramadan mean morning phosphate was higher and the evening level lower was than Shabaan values (p = 0.010 and p <0.001, respectively), while mean iPTH level was decreased compared with the morning value (p = 0.001), and the evening mean during Shabaan (p = 0.029). Mean IgG concentration was significantly lower during Ramadan (p = 0.003 and p = 0.021 for morning and evening, respectively).

CONCLUSIONS

Changes in dietary practices during Ramadan modulated PTH secretion to a pattern which might be beneficial to bone health. Combined effects of fasting and disturbed sleep led to a noted decrease in IgG level. Therefore, a possible beneficial effect of fasting on bone turnover is combined with decreased immune response.

Effects of Ramadan fasting on glucose homeostasis and adiponectin levels in healthy adult males

BACKGROUND

Adiponectin is a hormone secreted by adipocytes during the fasting phase of the fast-fed cycle. Ramadan fasting involves prolonged fasting for up to twelve hours and thus could lead to increased secretion of adiponectin by adipocytes. However, studies on the role of adiponectin on glucose and body weight homeostasis during Ramadan fasting is still a matter of controversy. Thus the specific aim of this study was to assess the effect of fasting during Ramadan on the adiponectin levels, body weight and glucose homeostasis in healthy male Malaysian subjects.

METHODS

Twenty healthy male (19-23 years) Muslim subjects were followed up during the fasting month of Ramadan. Anthropometry and blood samples were taken one week before and during the fourth week of fasting. Plasma glucose, insulin and adiponectin were estimated and insulin sensitivity indices were estimated using the Homeostasis Model Assessment.

RESULTS

Subjects experienced a significant decrease in body weight (2.4 %, p < 0.001) and body mass index (5.5 %, p < 0.01). There was also a significant decrease of 12.3 %, 52.8 % and 45.6 % of plasma glucose, insulin and adiponectin respectively (p < 0.01). The drop in adiponectin was positively correlated with the decrease in body weight (r = 0.45, p < 0.05). There was also a significant increase in insulin sensitivity and a decrease in insulin resistance (p < 0.01).

CONCLUSIONS

These results indicate that Ramadan fasting in young healthy individuals has a positive impact on the maintenance of glucose homeostasis. It also shows that adiponectin levels dropped along with significant loss in weight. We feel caloric restriction during the Ramadan fasting is in itself sufficient to improve insulin sensitivity in healthy individuals.