Islamic fasting and weight loss: a systematic review and meta-analysis

The optimal time restricted eating interventions for blood pressure, weight, fat mass, glucose, and lipids: A meta-analysis and systematic review

BACKGROUND

No previous systematic review or meta-analysis has evaluated the effect of optimal time-restricted eating (TRE) interventions on cardiovascular (CVD) risk factors. This meta-analysis aimed to illustrate the effect of a suitable TRE on CVD risk factors.

METHODS

A systematic review was performed to identify trials reporting the effects of TRE, relative to non-diet controls, on CVD risk factors in humans. A random-effects model was used to evaluate the effect sizes, and the results are expressed as the mean difference (MD) and 95% confidence intervals (CIs). Subgroup analyses were performed to examine the influence of the study population, age, duration of intervention, and baseline mean BMI on the CVD indexes.

RESULTS

TRE intervention significantly reduced systolic pressure (SBP) (MD: -3.45 mmHg; 95%CI:(-6.20,-0.71) mmHg; P = 0.01), body weight (MD: -1.63 Kg; 95%CI:(-2.09,-1.17) Kg; P<0.001), body mass index (BMI) (MD: -0.47 Kg/m2; 95% CI: (-0.72, -0.22) Kg/m2; P<0.001), and fat mass (MD: -0.98 Kg; 95% CI: (-1.51,-0.44) Kg; P<0.001), and reduced blood glucose levels. Based on the results of subgroup analysis, this meta-analysis identified the optimal TRE for BP (with a 6 h feeding window, last eating time point at 6-8 PM, and male participants with obesity and aged ≥ 45 years), obesity (with a 6 h feeding window, last eating time point at 6-8 PM, and female participants aged ≥ 45 years), lipids (with an 8 h feeding window, last eating time point at 6-8 PM, and male participants aged < 45 years), and glucose (with a 10-12 h feeding window, last eating time point before 6 PM, and female participants aged < 45years).

CONCLUSIONS

Relative to a non-diet control, TRE is effective for the improvement of CVD risks. Moreover, individual TRE interventions should be developed for different populations to achieve the most effective health improvement for CVD risk factors.

Intermittent Fasting: Myths, Fakes and Truth on This Dietary Regimen Approach

Intermittent fasting (IF) has been indicated as a valuable alternative to the classical caloric restriction dietary regimen for lowering body weight and preventing obesity-related complications, such as metabolic syndrome and type II diabetes. However, is it effective? In this review article, we analyzed over 50 clinical studies in which IF, conducted by alternate day fasting (ADF) or time-restricted feeding (TRF), was compared with the caloric restriction approach. We evaluated the different roles of IF in treating and preventing human disorders such as metabolic syndrome, type II diabetes, and some types of cancer, as well as the usefulness of IF in reducing body weight and cardiovascular risk factors such as hypertension. Furthermore, we explored the cellular pathways targeted by IF to exert their beneficial effects by activating effector proteins that modulate cell functions and resistance to oxidative stress. In contrast, we investigated concerns regarding human health related to the adoption of IF dietary regimens, highlighting the profound debate surrounding weight loss regimens. We examined and compared several clinical trials to formulate an updated concept regarding IF and its therapeutic potential.

Effects of Modified Ramadan Fasting on Mental Well-Being and Biomarkers in Healthy Adult Muslims - A Randomised Controlled Trial

BACKGROUND

Ramadan fasting has seen increased attention in research, often with inconsistent findings. This study aims to investigate whether dietary and lifestyle modifications during Ramadan can improve well-being and health in healthy adult Muslims.

METHOD

A randomised controlled trial with two parallel groups was conducted in an outpatient clinic of a university hospital in Essen, Germany, in 2016. Healthy adult Muslims (n = 114) aged 18-60 years were randomised to a modified fasting group; i.e., they received educational material prompting dietary and lifestyle modifications pre-Ramadan, and a control group who undertook Ramadan fasting as usual. Primary outcome was quality of life (WHO-5 Well-Being Index). Secondary outcomes included sleep quality, spirituality, and mindfulness (all self-report), body weight, body mass index, body fat, waist circumference, hip circumference, blood pressure, and heart rate, as well as blood serum biomarkers. Safety was examined via adverse events.

RESULTS

The modified fasting group reported significantly higher quality of life (WHO-5) compared to the control after Ramadan (MD 5.9; 95% CI, 0.02-11.8; p < 0.05). Group differences in favour of the modified fasting were also found for satisfaction with health (MD 5.9, 95% CI 0.19-11.67), ease of life (MD 4.1, 95% CI 0.38-7.80) and mindfulness (MD 7.6, 95% CI 2.68-12.52), reductions in weight (MD, - 0.9 kg; 95% CI - 1.39 to - 0.42), BMI (MD - 0.3 kg/m2, 95% CI - 0.50 to - 0.15), hip circumference (MD - 0.3 kg/m2, 95% CI - 0.50 to - 0.15), and diastolic blood pressure (MD - 2.8 mmHg, 95% CI - 5.15 to - 0.43). About 60% of participants reported adverse events, mostly headaches/migraines, dizziness/fatigue, common cold, and gastrointestinal symptoms, with no group differences. One serious non-related adverse event each occurred in both groups.

CONCLUSION

Pre-Ramadan dietary and lifestyle advice can lead to short-term improvements in mental and physical well-being of adult Muslims observing Ramadan. As such, this study demonstrates the potential benefits of culturally appropriate health interventions in a religious context.

TRIAL REGISTRATION

ClinicalTrials.gov (Identifier NCT02775175).

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.

An umbrella review and meta-analysis of meta-analyses of the impact of Ramadan fasting on the metabolic syndrome components

CONTEXT

Ramadan is a holy month of fasting, spiritual reflection, and worship for Muslims worldwide. However, the Ramadan fast - which involves abstaining from all food and drink, sunrise to sunset for 29 days-30 days annually - may also influence physical health outcomes, especially relating to the risk of metabolic syndrome.

OBJECTIVE

The literature from the top of the pyramid of evidence was gathered and synthesized for this comprehensive umbrella review and meta-analysis of meta-analyses in order to provide an overall conclusion on the impact of Ramadan fasting with regard to metabolic syndrome components.

DATA EXTRACTION

Eleven systematic reviews and meta-analyses were included in the current umbrella review. Nine components, including waist circumference, body weight), high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure), and fasting blood plasma glucose were analyzed.

DATA ANALYSIS

The random-effects meta-analysis results revealed standard mean differences as follows: waist circumference -0.30 (95% confidence interval [CI] -0.33 to -0.27), body weight -0.34 (95% CI -0.39 to -0.29), high-density lipoprotein 0.20 (95% CI 0.10 to 0.30), low-density lipoprotein -0.10 (95% CI -0.13 to -0.07), total cholesterol -0.15 (95% CI -0.21 to -0.09), triglycerides -0.16 (95% CI -0.24 to -0.08), systolic blood pressure -0.20 (95% CI -0.23 to -0.17), diastolic blood pressure -0.20 (95% CI -0.22 to -0.18), fasting blood plasma glucose -0.10 (95% CI -0.12 to -0.08).

CONCLUSION

Ramadan fasting appears to benefit body weight, lipid profile, blood pressure, and fasting blood glucose levels. Therefore, engaging in fasting during Ramadan may contribute to weight reduction, decreased cardiovascular disease risk, improved blood pressure, and enhanced glycemic control. Nevertheless, the methodological quality of the included reviews ranged from low to critically low, necessitating cautious interpretation of conclusions drawn from these data.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework Identifier: DOI 10.17605/OSF.IO/9WVJZ.

Effects of Ramadan intermittent fasting on performance, physiological responses, and bioenergetic pathway contributions during repeated sprint exercise

Introduction

This investigation aims to elucidate the impact of Ramadan intermittent fasting on performance, physiological responses, and bioenergetic pathway contributions during repeated sprints.

Methods

Fourteen active male Muslim athletes (age = 22.4 ± 1.8 years, body weight = 69.5 ± 3.8 kg, height = 176 ± 5.1 cm) executed a repeated sprint protocol, consisting of ten 20-meter sprints with 15-s passive recovery intervals, during both fasting and non-fasting conditions. The fasting session was conducted after a 12-14 h fast following Sahur (the pre-dawn meal during Ramadan). In contrast, the non-fasting session occurred before the Ramadan fasting period began, during the same hours of the day, at a time when fasting was not yet required for the athletes. Bioenergetic pathway contributions during repeated sprints were quantified using the PCr-LA-O2 method.

Results

The mean sprint time during fasting sessions was 3.4 ± 0.3 s compared to 3.3 ± 0.2 s in non-fasting sessions, indicating a trend approaching the threshold of significance for slower times in the fasted state (p = 0.052, effect size (ES) = 0.34). In terms of bioenergetic contributions, the total metabolic energy expenditure (TEE) was slightly lower during fasting sessions (236.5 ± 22 kJ) compared to non-fasting sessions (245.2 ± 21.7 kJ), but this difference was not statistically significant (p = 0.102, ES = 0.40). Similarly, metabolic energy expenditure per sprint was 23.7 ± 2.2 kJ in fasting conditions compared to 24.5 ± 2.2 kJ in non-fasting conditions (p = 0.106, ES = 0.35). The oxidative energy contribution did not differ significantly between fasting (34.2 ± 4.1 kJ) and non-fasting conditions (34.2 ± 4.1 vs. 35.5 ± 5.2 kJ; p = 0.238, ES = 0.28). Similarly, lactic (60.4 ± 7.6 vs. 59.2 ± 8.3 kJ; p = 0.484, ES = 0.15); and alactic (149.3 ± 19.9 vs. 143 ± 21.5 kJ; p = 0.137, ES = 0.30) energy contributions showed no significant differences between the fasting and non-fasting sessions. The percentage of performance decrement (Pdec) and the percentage contributions of oxidative, lactic, and alactic pathways to the total energy expenditure did not differ significantly between the fasting and non-fasting conditions, indicating a similar bioenergetic profile across both conditions.

Conclusion

The present findings indicate no significant differences in performance metrics and metabolic outcomes between fasted and non-fasted states. Future assessments with longer duration and higher intensity protocols may provide further insights.

Metabolic changes with intermittent fasting

BACKGROUND

The prevalence of obesity is rising globally and effective strategies to treat obesity are needed. Intermittent fasting, a dietary intervention for weight management, has received growing interest from the general public, as well as healthcare professionals, as a form of lifestyle intervention.

METHODS

We executed a rapid review using PUBMED database to identify systematic reviews that examined the impact of intermittent fasting on metabolic indices, published between 2011 and 2022.

RESULTS

Intermittent fasting leads to weight loss of a similar magnitude to continuous energy restriction. Most of the evidence shows that intermittent fasting leads to greater fat loss as measured by fat mass (kg) or body fat percentage compared to an ad libitum diet, but fat loss attained during intermittent fasting is not significantly different to continuous energy restriction, although recent evidence shows intermittent fasting to be superior. There is mixed evidence for the impact of intermittent fasting on insulin resistance, fasting glucose and lipid profile. Some studies focused on populations of Muslim people, which showed that Ramadan fasting may lead to weight loss and improvement of metabolic parameters during fasting, although the effects are reversed when fasting is finished.

CONCLUSIONS

Intermittent fasting is more effective than an ad libitum dietary intake, and equally or more effective as continuous energy restriction, for weight management. However, there is inconclusive evidence on whether intermittent fasting has a clinically beneficial effect on glucose and lipid metabolism.

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.

Impact of Ramadan Fasting on Cardiometabolic and InflammatoryBiomarkers among Saudi Adults with Diabetes

BACKGROUND AND AIMS

Diabetes is prevalent in Saudi Arabia. As dietary concerns are central in patients with diabetes, the impact of fasting on health during Ramadan is potentially significant. Decreased meal frequency and changes in food type and amount affect body weight and metabolic profiles. This study aimed to investigate the association between Ramadan fasting and anthropometric measurements and cardiometabolic and inflammatory biomarkers in Saudi adults with diabetes.

METHODS

Sixty-eight Saudi adults with diabetes, admitted at the University Diabetes Centre in Riyadh, Saudi Arabia, were enrolled in this study. Participants were evaluated at the following time points: Six weeks before Ramadan (pre-fasting) and at least 15 days after the initiation of Ramadan (peri-fasting). Anthropometric measurements and cardiometabolic and inflammatory biomarker levels were assessed during both visits.

RESULTS

After accounting for confounding factors, Ramadan fasting was found to be associated with reduced body weight (kg), waist circumference (cm), and hip circumference (cm). Increased log high-density lipoprotein-cholesterol and decreased log interleukin 6 and C-reactive protein levels were observed.

CONCLUSIONS

Ramadan fasting was associated with increased HDL-C levels and decreased anthropometric measurements and inflammatory cytokine levels. These results support the beneficial role of Ramadan fasting in reducing cardiometabolic abnormalities and inflammation in adults with diabetes.

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.

Fluctuations of serum fibroblast growth factor-21 levels in prolonged fasting in male adults

BACKGROUND & AIMS

Fibroblast Growth Factor-21 (FGF21) is a significant protein in the process of adaptation to fasting. The aim of this cross-sectional study to examine the effects of fasting on serum FGF21 levels, nutritional status, and anthropometric measurements of adult males during prolonged Ramadan fasting.

METHODS

This study included a total of 12 healthy individuals with normal body mass index, between the ages of 18-35. All individuals fasted for 16 h each day for 29 days of Ramadan. A questionnaire was administered to determine individuals' general characteristics and nutritional habits. Anthropometric measurements, 24-h dietary recall, and physical activities were recorded, and blood samples were collected four times in the following periods: before Ramadan, 1st week of Ramadan, 3rd week of Ramadan and 4 weeks after Ramadan.

RESULTS

It was observed that serum FGF21 levels increased until the 1st week of fasting. Remarkably, FGF21 levels declined in most subjects during the late phase of fasting and continued to decrease until 4 weeks after fasting. There was a positive correlation between serum FGF21 levels and protein intake at the 3rd week of fasting. Individuals' PAL and energy expenditure increased during fasting and continued to increase until 4 weeks after fasting. Energy intake, on the other hand, decreased from baseline until 4 weeks after fasting.

CONCLUSION

FGF21 serum levels may show an increase during fasting, however in long-term fasting periods like Ramadan it may decrease back to the beginning levels, therefore, FGF21 serum levels must be evaluated carefully.

Umbrella review of time-restricted eating on weight loss, fasting blood glucose, and lipid profile

CONTEXT

A growing number of systematic reviews with meta-analyses have examined the effectiveness of time-restricted eating (TRE) in reducing weight and improving fasting blood glucose and lipid profiles. However, mixed results have been found, and its effectiveness remains uncertain.

OBJECTIVE

This umbrella review aimed to summarize systematic reviews that (1) examine the effects of TRE on weight loss, fasting blood glucose, total cholesterol, triglycerides, high-density-lipoprotein cholesterol (HDL-C) and low-density-lipoprotein cholesterol (LDL-C) in individuals with overweight and obesity; and (2) compare the effect sizes on these outcomes between conventional TRE and Ramadan fasting.

DATA SOURCES

A total of 11 databases were searched from inception until March 11, 2022.

DATA EXTRACTION

Two independent reviewers performed article selection, data extraction, and quality assessment.

DATA ANALYSIS

Seven systematic reviews with 30 unique meta-analyses involving 7231 participants from 184 primary studies were included. The quality of each review was evaluated as moderate (14.3%) or critically low (85.7%) according to the Assessment of Multiple Systematic Reviews 2. The degree of overlap was rated as slight for all outcomes (corrected cover area = 1.04%-4.27%). Meta-analyses at the meta-data level suggest that TRE is beneficial for reducing weight (P = .006) and fasting blood glucose (P < .01). Meta-analyses at the primary study level suggest that the effect on LGL-C was significant (P = .03). Subgroup analyses revealed greater effects in lowering fasting blood glucose, total cholesterol, and LDL-C from Ramadan fasting than from conventional TRE. The credibility of evidence was rated as suggestive (3.3%), weak (36.7%) or nonsignificant (60%) using a classification method.

CONCLUSION

TRE may complement usual care and reduce body weight and fasting blood glucose. Rigorous randomized controlled trials with long-term assessments in a wide range of populations are warranted.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022325657.

Timing of energy intake and the therapeutic potential of intermittent fasting and time-restricted eating in NAFLD

Non-alcoholic fatty liver disease (NAFLD) represents a major public health concern and is associated with a substantial global burden of liver-related and cardiovascular-related morbidity and mortality. High total energy intake coupled with unhealthy consumption of ultra-processed foods and saturated fats have long been regarded as major dietary drivers of NAFLD. However, there is an accumulating body of evidence demonstrating that the timing of energy intake across a the day is also an important determinant of individual risk for NAFLD and associated metabolic conditions. This review summarises the available observational and epidemiological data describing associations between eating patterns and metabolic disease, including the negative effects of irregular meal patterns, skipping breakfast and night-time eating on liver health. We suggest that that these harmful behaviours deserve greater consideration in the risk stratification and management of patients with NAFLD particularly in a 24-hour society with continuous availability of food and with up to 20% of the population now engaged in shiftwork with mistimed eating patterns. We also draw on studies reporting the liver-specific impact of Ramadan, which represents a unique real-world opportunity to explore the physiological impact of fasting. By highlighting data from preclinical and pilot human studies, we present a further biological rationale for manipulating timing of energy intake to improve metabolic health and discuss how this may be mediated through restoration of natural circadian rhythms. Lastly, we comprehensively review the landscape of human trials of intermittent fasting and time-restricted eating in metabolic disease and offer a look to the future about how these dietary strategies may benefit patients with NAFLD and non-alcoholic steatohepatitis.

Shared correlates of maternal and childhood overweight in Cameroon: a cross-sectional analysis of demographic and health survey data

BACKGROUND

Overweight parents are likelier to bear overweight babies, who are likelier to grow into overweight adults. Understanding the shared risks of being overweight between the mother-child dyad is essential for targeted life course interventions. In this study, we aimed to identify such risk factors in Cameroon.

METHODS

We conducted secondary data analysis using Cameroon's 2018 Demographic and Health Surveys. We used weighted multilevel binary logistic regressions to examine individual, household, and community correlates of maternal (15-49 years) and child (under five years) overweight.

RESULTS

We retained 4511 complete records for childhood and 4644 for maternal analysis. We found that 37% [95%CI:36-38%] of mothers and 12% [95%CI:11-13%] of children were overweight or obese. Many environmental and sociodemographic factors were positively associated with maternal overweight, namely urban residence, wealthier households, higher education, parity and being a Christian. Childhood overweight was positively associated with a child being older and a mother being overweight, a worker, or a Christian. Therefore, only religion affected both mothers overweight (aOR: 0.71[95%CI:0.56-0.91]) and childhood overweight (aOR 0.67[95%CI: 0.5-0.91]). Most of the potentially shared factors only indirectly affected childhood overweight through maternal overweight.

CONCLUSION

Besides religion, which affects both mothers and childhood overweight (with the Muslim faith being protective), much of childhood overweight is not directly explained by many of the observed determinants of maternal overweight. These determinants are likely to influence childhood overweight indirectly through maternal overweight. Extending this analysis to include unobserved correlates such as physical activity, dietary, and genetic characteristics would produce a more comprehensive picture of shared mother-child overweight correlates.

Effect of Ramadan Fasting on Body Weight and Body Mass Index (BMI) in Public Sector Undergraduate Medical Students of Peshawar

Objective

To determine the effects of fasting on weight and eventually on Body Mass Index (BMI) in medical students of a Public Sector Medical College.

Methods

It was a prospective analytical study conducted in a Public Sector Medical College in Peshawar City from 28th March to 20th May 2022 (1443 Hijri). Convenience Sampling was used and 115 students (58 male and 57 female) of 1st Year MBBS to Final Year MBBS were enrolled. Four readings of weight were taken, one before, two during, and one after Ramadan. A well-structured self-administered questionnaire was used to inquire about basic demographic characteristics, sleep patterns during Ramadan and normal routine, and family history of obesity. The collected data were analyzed through SPSS software and a repeated measures ANOVA test was used for drawing statistical conclusions.

Results

A slight increase in the mean weight was observed during the second week of Ramadan while a loss of 0.4 kg occurred during the fourth week of Ramadan, F (1, 81) = 1777.55; p < 0.0001. The same pattern was observed for BMI, F (1, 81) = 2705.18; p < 0.0001. However, the weight and the BMI were regained in two to three weeks following Ramadan.

Conclusion

Ramadan offers a non-hazardous way of weight loss. Further studies across different geographical locations with larger sample sizes should be conducted to identify and quantify the association between weight and fasting and also to identify potential confounders.

Effects of Ramadan Fasting on Glycaemic Control Among Patients with Type 2 Diabetes: Systematic Review and Meta-analysis of Observational Studies

INTRODUCTION

The prevalence of type 2 diabetes (T2D) is increasing around the world. Although Muslims with a physical illness are exempted from fasting during the month of Ramadan, a great number still choose to fast, often without medical consultations. The aim of this systematic review and meta-analysis was to investigate the impact of observing Ramadan fasting (RF) on glycaemic control in patients with T2D.

METHODS

The Web of Science, Scopus, EBSCOhost, CINAHL, ScienceDirect, Cochrane Library, ProQuest Central and Europe PubMed Central (Medline) databases were searched for relevant studies published between January 2000 and December 2021. Observational studies that examined the changes in body weight (BW) and glucose parameters (glycosylated haemoglobin [HbA1c] and fasting blood glucose [FBG]), before and after RF among different age groups with T2D were included in the systemic review and meta-analysis. Effect sizes for the tested outcomes were calculated as weighted mean difference (WMD), with their confidence intervals (CI). Quality assessment was examined using the National Heart, Lung, and Blood Institute (NHLBI) tool.

RESULTS

Of the 1592 identified records, 12 studies conducted in Middle Eastern and Asian countries were eligible and included in the quantitative analyses. The quality of the retrieved studies was evaluated and found to range between fair (83%) and good (17%). These 12 studies included 5554 participants of whom 54% were males and 46% were females. Our pooled analysis demonstrated that HbA1c and FBG levels significantly decreased after RF when compared to the pre-fasting levels (WMD = 0.55 mg/dl, 95% CI 0.33-0.77, P < 0.00001, Ι² = 93% and WMD = 12.42, CI 6.46-18.38, P < 0.0001, Ι² = 81%, respectively). However, the difference in BW in fasting patients after RF versus the pre-fasting stage was non-significant. Although, young patients with T2D were enrolled in the 12 selected studies, we did not find any studies that solely focussed on this group.

CONCLUSION

The impact of RF on adult patients with T2D is associated with favorable outcomes. However, future studies should evaluate data from young adults separately. In addition, it is essential to identify the effects of the number of fasting days (level of exposure), diet, level of physical activity and sleeping pattern on optimal glycaemic control. This information could be utilized by medical professionals as a non-pharmacological therapeutic method for management of diabetes in patients who are willing to practice fasting during Ramadan and other months of the year.

STUDY REGISTRATION

PROSPERO: CRD42022314752.

Advances in circadian clock regulation of reproduction

The mammalian circadian clock is an endogenously regulated oscillator that is synchronized with solar time and cycle within a 24-h period. The circadian clock exists not only in the suprachiasmatic nucleus (SCN) of the hypothalamus, a central pacemaker of the circadian clock system, but also in numerous peripheral tissues known as peripheral circadian oscillators. The SCN and peripheral circadian oscillators mutually orchestrate the diurnal rhythms of various physiological and behavioral processes in a hierarchical manner. In the past two decades, peripheral circadian oscillators have been identified and their function has been determined in the mammalian reproductive system and its related endocrine glands, including the hypothalamus, pituitary gland, ovaries, testes, uterus, mammary glands, and prostate gland. Increasing evidence indicates that both the SCN and peripheral circadian oscillators play discrete roles in coordinating reproductive processes and optimizing fertility in mammals. The present study reviews recent evidence on circadian clock regulation of reproductive function in the hypothalamic-pituitary-gonadal axis and reproductive system. Additionally, we elucidate the effects of chronodisruption (as a result of, for example, shift work, jet lag, disrupted eating patterns, and sleep disorders) on mammalian reproductive performance from multiple aspects. Finally, we propose potential behavioral changes or pharmaceutical strategies for the prevention and treatment of reproductive disorders from the perspective of chronomedicine. Conclusively, this review will outline recent evidence on circadian clock regulation of reproduction, providing novel perspectives on the role of the circadian clock in maintaining normal reproductive functions and in diseases that negatively affect fertility.

The impact of Ramadan intermittent fasting on anthropometric measurements and body composition: Evidence from LORANS study and a meta-analysis

Background

Although the effect of Ramadan intermittent fasting (RIF) on anthropometry and body composition has been questioned, none of the previous studies tried to explain the reported changes in these parameters. Also, systematic reviews that investigated the topic were limited to healthy individuals or a specific disease group.

Methods

The London Ramadan Study (LORANS) is an observational study on health effects of RIF. We measured weight, waist circumference (WC), hip circumference (HC), body mass index (BMI), waist-to-hip ratio (WHR), basal metabolic rate (BMR), fat percentage (FP), free-fat mass (FFM), extremities predicted muscle mass, total body water (TBW), trunk FM, trunk FFM and trunk predicted muscle mass before and immediately after Ramadan. Using mixed-effects regression models, we investigated the effect of RIF with adjustment for potential confounders. We also conducted a meta-analysis of the results of LORANS with other studies that investigated the effect of RIF on anthropometry and body composition. The review protocol is registered with PROSPERO registry (CRD42020186532).

Results

We recruited 146 participants (Mean ± SD age = 43.3 ± 15 years). Immediately after Ramadan, compared with before Ramadan, the mean difference was-1.6 kg (P<0.01) in weight,-1.95cm (P<0.01) in WC,-2.86cm (P <0.01) in HC, -0.60 kg/m2 (P < 0.01) in BMI and -1.24 kg (P < 0.01) in FM. In the systematic review and meta-analysis, after screening 2,150 titles and abstracts, 66 studies comprising 7,611 participants were included. In the general population, RIF was followed by a reduction of 1.12 Kg in body weight (-1.89- -0.36, I2 = 0), 0.74 kg/m2 reduction in BMI (-0.96- -0.53, I2 = 0), 1.54cm reduction in WC (-2.37- -0.71, I2 = 0) and 1.76cm reduction in HC (-2.69- -0.83, I2 = 0). The effect of fasting on anthropometric and body composition parameters starts to manifest in the second week of Ramadan and starts to diminish 3 weeks after Ramadan.

Conclusion

RIF is associated with a reduction in body weight, BMI, WC, HC, FM, FP and TBW. Most of these reductions are partially attributed to reduced FM and TBW. The reductions in these parameters appear to reverse after Ramadan.

Effect of empagliflozin in patients with type 2 diabetes during Ramadan on volume status, ketonaemia, and hypoglycaemia

BACKGROUND AND AIMS

Patients with type 2 diabetes (T2D) carry higher risk of glycaemic variability during Ramadan. Glucose-lowering medications such as SGLT2 inhibitors are also associated with genitourinary infection, acute kidney injury, and euglycaemic diabetic ketoacidosis. Limited data is available on the effects of SGLT2 inhibitors on T2D patients during Ramadan. We investigated effects of empagliflozin use in fasting T2D patients.

METHODS

This was a prospective cohort study in a single diabetes centre in Malaysia. Empagliflozin group were on study drug for at least three months. For control group, subjects not receiving SGLT2 inhibitors were recruited. Follow-up were performed before and during Ramadan fasting. Anthropometric measurements, blood pressure, renal profile, and blood ketone were recorded during visits. Hypoglycaemia symptoms were assessed via hypoglycaemia symptom rating questionnaire (HypoSRQ).

RESULTS

We recruited a total of 98 subjects. Baseline anthropometry, blood pressure, and renal parameters were similar in two groups. No significant changes in blood pressure, weight, urea, creatinine, eGFR, or haemoglobin levels during Ramadan was found in either group. Likewise, no difference was detected in blood ketone levels (empagliflozin vs control, 0.17 ± 0.247 mmol/L vs 0.13 ± 0.082 mmol/L, p = 0.304) or hypoglycaemia indices (empagliflozin vs control, 19.1% vs 16%, p = 0.684).

CONCLUSIONS

Ramadan fasting resulted in weight loss and reduction in eGFR levels in patients with T2D. Empagliflozin use during Ramadan is safe and not associated with increased risk of dehydration, ketosis, or hypoglycaemia. Therefore, empagliflozin is a viable glucose-lowering drug for patients with T2D planning for Ramadan fasting.

Religious fasting and its impacts on individual, public, and planetary health: Fasting as a "religious health asset" for a healthier, more equitable, and sustainable society

Religious fasting is practiced by people of all faiths, including Christianity, Islam, Buddhism, Jainism, as well as Hinduism, Judaism, and Taoism. Individual/clinical, public, global, and planetary health has traditionally been studied as separate entities. Nevertheless, religious fasting, in conjunction with other religious health assets, can provide several opportunities, ranging from the individual to the population, environmental, and planetary levels, by facilitating and supporting societal transformations and changes, such as the adoption of healthier, more equitable, and sustainable lifestyles, therein preserving the Earth's systems and addressing major interconnected, cascading, and compound challenges. In this review, we will summarize the most recent evidence on the effects of religious fasting, particularly Orthodox and Ramadan Islamic fasting, on human and public health. Further, we will explore the potential effects of religious fasting on tackling current environmental issues, with a special focus on nutrition/food restriction and planetary health. Finally, specific recommendations, particularly around dietary intake during the fasting rituals, will be provided to ensure a sustainable healthy planet.

Complex physiology and clinical implications of time-restricted eating

Time-restricted eating (TRE) is a dietary intervention that limits food consumption to a specific time window each day. The effect of TRE on body weight and physiological functions has been extensively studied in rodent models, which have shown considerable therapeutic effects of TRE and important interactions among time of eating, circadian biology, and metabolic homeostasis. In contrast, it is difficult to make firm conclusions regarding the effect of TRE in people because of the heterogeneity in results, TRE regimens, and study populations. In this review, we 1) provide a background of the history of meal consumption in people and the normal physiology of eating and fasting; 2) discuss the interaction between circadian molecular metabolism and TRE; 3) integrate the results of preclinical and clinical studies that evaluated the effects of TRE on body weight and physiological functions; 4) summarize other time-related dietary interventions that have been studied in people; and 4) identify current gaps in knowledge and provide a framework for future research directions.

Infodemiology on diet and weight loss behavior before and during COVID-19 pandemic in Indonesia: Implication for public health promotion

Objective

This study set out to explore public interest through information search trends on diet and weight loss before and during the COVID-19 pandemic in Indonesia.

Methods

The Google Trends database was evaluated for the relative internet search popularity on diet-related search terms, including top and rising diet-related terms. The search range was before and during the COVID-19 pandemic (April 2018 to January 2022) in the Indonesia region. We analyzed the Relative Search Volume (RSV) data using line charts, correlation, and comparison tests.

Results

Search queries of “lose weight” was higher during the pandemic (58.34 ± 9.70 vs. 68.69 ± 7.72; p<0.05). No difference was found in diet-related searches before and after the pandemic. Public interest in the diet was higher after Eid al-Fitr (Muslims break fasting celebration day) and after the new year. Many fad diet (FD) terms were found on the top and rising terms.

Conclusion

After Eid al-Fitr and the new year were susceptible times for promoting a healthy diet in Indonesia. Potential need found before those times for education in inserting healthy food among fatty and sugary menus related to holidays and celebrations. Higher interest in “lose weight” was relevant to heightened obesity risk during the social restriction and heightened COVID-19 morbidity and mortality due to obesity. The high interest for rapid weight loss through FD needs to be resolved by promoting healthy diets with a more captivating message and messenger, like consistently using top terms in the keywords of the official healthy diet guidance. Future research could explore the relationship between diet and other behavior or with non-communicable diseases.

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 positively modulates human gut microbial diversity and ameliorates blood lipid profile

Aim

The aim was to evaluate the impact of intermittent fasting (IF) on human body mass index (BMI) and serum lipid profile thorough constructive rectification of gut microbiota.

Methods and results

Fourteen healthy women and thirty-one men were included in the study. Their blood and fecal samples were collected before and at the end of the study. Blood parameters, anthropometric values, and gut microbiology were noted to investigate the impact of intermittent fasting (IF) on human gut microbiota and physiology. Our data revealed that IF reduces the body weight and improves blood lipid profile, such as increasing high-density lipoprotein (HDL) and decreasing total cholesterol, triglycerides, and low- and very low-density lipoprotein levels. IF also decreases culturable aerobic bacterial count and increased fungal count. It was also found that the gut metagenome is altered considerably after IF. The human fecal bacterial diversity exhibited significant changes in decreased overall bacterial population, increased bacterial diversity (alpha diversity), and promoted evenness within the bacterial population at the species level. Anti-inflammatory bacteria Lactobacillus and Bifidobacterium were favorably increased, while pathogenic bacteria were decreased.

Conclusion

Collectively, these results indicated that IF could improve lipid profile and body weight in humans, and the potential mechanisms might be via regulating gut microbiota.

Significance and impact of the study

We demonstrated for the first time that IF improved body weight and blood lipid profile, indicating that IF could mitigate gut microbiota in humans.

The effect of Ramadan fasting on nasal mucociliary activity and peak nasal inspiratory flow

PURPOSE

In this study, we aimed to investigate the effect of Ramadan fasting (RF) on nasal mucociliary clearance (MCC) and peak nasal inspiratory flow (PNIF).

METHODS

Sixty-two (41 male and 21 female) healthy subjects who stated that they would fast continuously during the month of Ramadan were included in this prospective study. Day 0 (baseline), 1st day (after one day of RF), and 29th (after 29 days of RF) nasal mucociliary clearance time (MCT) with saccharine test and PNIF values were determined. Subject weights (SW) were measured on Day 0 and Day 29. The obtained data were analyzed statistically.

RESULTS

The mean of SW on day 0 was 78.53 ± 10.95 kg, and the mean of SW on Day 29 was 78.69 ± 10.87 kg. There was no significant difference in terms of SW (p = 0.251, p > 0.05). A significant difference was found between the MCT and PNIF values measured on different study days (p < 0.05). The MCT values for Day 29 were significantly higher than the values for other days (p < 0.05). There was no significant difference between the MCT values on the first day and the baseline (p = 0.891, p > 0.05). The PNIF values for Day 29 were significantly higher than the values for other days (p < 0.05). The PNIF values on the first day were significantly higher than the baseline (p = 0.008, p < 0.05).

CONCLUSION

The present study showed that RF leads to MCT prolongation and PNIF increase. Ramadan fasting causes deterioration in nasal airway defense and improvement in nasal respiration.

Ramadan Fasting and Maternal and Fetal Outcomes in Pregnant Women with Diabetes Mellitus: Literature Review

There is an emerging Muslim and diabetic population in the United States and other Western countries and majority of pregnant women and patients with diabetes mellitus choose to fast during Ramadan. Fasting during Ramadan in pregnant women with diabetes may represent a 'perfect storm' of metabolic disturbances including hyperglycemia, hypoglycemia and ketosis. Recent continuous and flash glucose monitoring data suggests increased glycemic variability (fasting hypo- and post-Iftar hyperglycemia) in non-pregnant patients with diabetes during Ramadan. Only five small-scale studies, predominantly focused on women with gestational diabetes mellitus in Muslim-majority nations have explored maternal glycemic outcomes during Ramadan which is associated with lower mean blood glucose levels and higher frequency of fasting hypoglycemia. Data is limited however on important clinical outcomes such as symptomatic and serious hypoglycemia requiring hospitalization. Results have been conflicting regarding maternal Ramadan fasting and association with fetal outcomes in women without diabetes. Only one recently published study reported on perinatal outcomes in pregnant women with gestational diabetes which found no effect of Ramadan exposure on mean birthweight or macrosomia frequency but lower neonatal hypoglycemia prevalence, however a significant limitation was lack of documentation of maternal fasting status. At this stage, due to paucity of data, the current medical recommendation is against Ramadan fasting for pregnant Muslim women with diabetes. Large-scale population-based studies are warranted regarding maternal and fetal outcomes in pregnant fasting women with diabetes and such studies should characterize maternal fasting status and have meaningful and consistent clinical outcomes. High-quality data derived from these studies can assist clinicians in providing more evidence-based advice to safely navigate both mother and fetus through a potentially challenging pregnancy.

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.

The impact of dawn to sunset fasting on immune system and its clinical significance in Covid-19 pandemic

Dawn to sunset fasting, a type of intermittent fasting commonly practiced in the month of Ramadan, requires fasting from dawn to sunset without food or liquid intake. Dawn and dusk are two transition time zones of the day that play a critical role in the human circadian rhythm. Practicing dawn to sunset fasting requires the alignment of mealtimes and wake-sleep times with the human biological dawn and dusk. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impairs immune cell responses at multiple levels and leads to severe Coronavirus Disease 2019 (COVID-19). It generates high levels of pro-inflammatory cytokines and chemokines, also known as a cytokine storm, leads to mitochondrial dysfunction and generation of excessive amounts of mitochondrial reactive oxygen species, downregulates autophagy to escape detection for unchecked replication, and alters gut microbiome composition. Severe cases of COVID-19 have been associated with several comorbidities that impair immune responses (e.g., obesity, diabetes, malignancy) and blood laboratory abnormalities (e.g., elevated procalcitonin, C-reactive protein, interleukin-6 (IL-6), leukocytosis, lymphopenia). Several studies of dawn to sunset fasting showed anti-inflammatory effect by suppressing several pro-inflammatory cytokines, reducing oxidative stress, inducing a proteome response associated with increased autophagy, remodeling the gut microbiome, and improving the components of metabolic syndrome (e.g., obesity, blood glucose levels, blood pressure, lipids). In conclusion, dawn to sunset fasting has the potential to optimize the immune system function against SARS-CoV-2 during the COVID-19 pandemic as it suppresses chronic inflammation and oxidative stress, improves metabolic profile, and remodels the gut microbiome. This review presents scientific literature related to the effects of dawn to sunset fasting on the immune system. Studies are needed to assess and confirm the potential benefits of dawn to sunset fasting against SARS-CoV-2.

Effect of Different Types of Intermittent Fasting on Biochemical and Anthropometric Parameters among Patients with Metabolic-Associated Fatty Liver Disease (MAFLD)-A Systematic Review

Metabolic-associated fatty liver disease (MAFLD), previously called non-alcoholic fatty liver disease (NAFLD), is the most common chronic liver disease worldwide. It is characterised by excessive fat accumulation in hepatocytes. Currently, no pharmacological therapy is effective for this disease, so non-pharmacological alternatives such as diet, supplementation or physical activity are being sought. For this reason, we reviewed the available databases to analyse the studies conducted to date using different modifications of intermittent fasting among patients with MAFLD. Eight studies using this dietary strategy were included in this review. The results obtained in the different trials are varied and do not allow a clear determination of the effect of the different types of intermittent fasting on anthropometric and biochemical parameters among patients with MAFLD. However, this type of diet seems to show some therapeutic potential, but further studies are needed.

Intermittent Fasting: A User-Friendly Method for Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is an alarmingly rising disorder characterized mainly by insulin resistance and hyperglycemia. Due to the impairment of glucose homeostasis, most subjects present with elevated serum glucose levels, which can lead to several complications, including hospitalizations and even death. Diet quality and quantity are at the heart of its pathogenesis; hence, for the management of this condition, a technique known as intermittent fasting (IF) has been an area of interest for researchers. Different fasting regimens, including alternate-day fasting, religious fasting, and time-restricted fasting, have proven to be of strategic importance for glycemic control due to their physiologic effects. According to case studies and randomized trials, therapeutic fasting has been shown to reverse insulin resistance, resulting in the discontinuance of insulin therapy while maintaining blood sugar levels.

Studies on IF have demonstrated their efficacy in glycemic control and other metabolic parameters, including reducing visceral fat and controlling inflammatory mediators and markers such as C-reactive protein (CRP) and interleukin-6 (IL-6), but control in obesity is its most significant effect as it acts as a risk factor for T2DM. Several case studies have shown a reduction in elevated hemoglobin A1c (HbA1c) levels in subjects after fasting, which some believe is due to sirtuin-6 (SIRT6) proteins. SIRT6 proteins are believed to be responsible for blood glucose homeostasis and insulin resistance reversal by increasing its sensitivity. This family of proteins is increased after fasting; hence, further research in this area will help researchers better understand its mechanism of action and potential therapeutic effects on T2DM. With an alarming increase in the incidence of T2DM around the world, a cost-effective strategy is required to control the disease with easy patient compliance, and IF might prove to be the solution.

Self-Care by Muslim Women during Ramadan Fasting to Protect Nutritional and Cardiovascular Health

The practice of Ramadan involves a series of changes in lifestyle, mainly in eating habits. The research aim of this study is to determine the prevalence of overweight-obesity, the degree of compliance with dietary recommendations and the effects of religious fasting on cardiovascular health among a population of Muslim women living in Melilla, a Spanish city in North Africa. A follow-up cohort study was conducted on 62 healthy adult women (33.6 ± 12.7 years). Anthropometric and body composition parameters were obtained using bioimpedance and dietary records. All of the participants were overweight or obese, especially due to the non-compliance with dietary recommendations; however, more than 60% considered their weight was appropriate or even low. By the end of Ramadan, the women's body mass index and fat component values had fallen significantly (p < 0.001), but this loss was later recovered. Dietary records revealed an excessive consumption of lipids and sodium, and the presence of a high waist-to-hip ratio. All of these factors are related to cardiovascular risk. In conclusion, promoting nutritional health and encouraging year-round self-care among adult Muslim women is necessary in order to ensure healthy fasting during Ramadan.

Fasting Interventions for Stress, Anxiety and Depressive Symptoms: A Systematic Review and Meta-Analysis

Background. Fasting interventions have shown effectiveness in alleviating stress, anxiety and depressive symptoms. However, no quantitative analysis has been carried out thus far. The objective was to determine the effectiveness of fasting interventions on stress, anxiety and depression and if these interventions were associated with increased or decreased fatigue/energy. Methods. Overall, 11 studies and 1436 participants were included in the quantitative analyses. Results. After limiting analyses to randomized controlled trials with low risk of bias, we found that fasting groups had lower anxiety (b = −0.508, p = 0.038), depression levels (b= −0.281, p = 0.012) and body mass index compared to controls without increased fatigue. There was no publication bias and no heterogeneity for these results. These interventions were safe, even in patients with type 2 diabetes. Conclusions. These results should be taken with a caveat. These results are preliminary and encouraging and fasting appears to be a safe intervention. Data are not sufficient to recommend one fasting intervention more than the others. No study was carried out in psychiatric populations and further trials should be carried out in these populations that may be good candidates for fasting interventions.

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 impact of circadian timing on energy balance: an extension of the energy balance model

A significant proportion of the population is classified as having overweight or obesity. One framework which has attempted to explain biobehavioral mechanisms influencing the development of overweight and obesity is the energy balance model. According to this model, the body continually attempts to balance energy intake with energy expenditure. When energy intake and energy expenditure become imbalanced, there is an increase in homeostatic and allostatic pressure, generally to either increase energy intake or decrease energy expenditure, so as to restore energy homeostasis.Recent research has indicated that circadian aspects of energy intake and energy expenditure may influence energy balance. This paper provides a narrative review of existing evidence of the role of circadian timing on components of energy balance. Research on the timing of food intake, physical activity, and sleep indicates that unhealthy timing is likely to increase risk of weight gain. Public health guidelines focus on how much individuals eat and sleep, what foods are consumed, and the type and frequency of exercise, but the field of circadian science has begun to demonstrate that when these behaviors occur may also influence overweight and obesity prevention and treatment efforts.

Muslim patients in Ramadan: A review for primary care physicians

Fasting Ramadan, in which Muslims abstain from specific habits and behaviors from dawn to sunset, is one of the five Pillars of Islam. While there are several exemptions from fasting, many Muslim patients with acute or chronic medical conditions still choose to fast, which may adversely affect their health if not addressed properly. Some patients may not be well educated about the effects of some medical treatments and procedures on the validity of their fast, which can unnecessarily lead to suboptimal management of their conditions or treatment nonadherence. Since spirituality, religiosity, and personal beliefs affect patients' health behaviors and adherence to treatments, health-care providers need to learn how fasting Ramadan can affect the health of their Muslim patients, especially those with chronic medical conditions, and how to help them achieve safe fasting. This article aims to provide an overview of the main topics that primary care physicians may need to know in order to improve their cultural competence when caring for their fasting Muslim patients.

A content analysis of food advertising in Arab Gulf countries during Ramadan

Research has explored the link between exposure to marketing of foods high in energy and low in nutrients, and obesity in Western countries. The prevalence of obesity in Arab Gulf countries is similar to that of Western countries, yet the influence of advertising and frequency of exposure to advertising of foods on subsequent food choices and health is largely unexplored. This project sought to examine the number and quality of foods advertised on television during Ramadan in Arab Gulf countries. Television programming (36 h total), 12 h each for three stations, Alwatan, Dubai and MBC, was recorded. Food and restaurant advertisements (ads) were classified, totaled and analysed for dietary healthfulness using the Model SSCg3d. Of the total ads aired (n = 1473), food and restaurant ads were the most common (20.4%). The ad type and frequency varied among channels with restaurant ads most common on Alwatan, drinks and soda ads on Dubai, and sweet snacks and desserts ads on MBC (p < 0.001). Channels also differed regarding the frequency of dairy food ads (p < 0.001). Most food ads promoted less healthy foods similar to marketing practices in other countries with high rates of obesity. Many ads promoted foods high in energy, saturated fat, sodium and added sugar. This work signals the need to further understand the relationship between advertising of nutrient-poor foods, food behaviours and obesity in Arab Gulf countries and how advertising regulations may address this public health issue.

A Clinical Perspective of Low Carbohydrate Ketogenic Diets: A Narrative Review

Low carbohydrates diets (LCDs), which provide 20–120 g of carbohydrates per day, have long been used as therapeutic options in the treatment of severe obesity, type 2 diabetes mellitus and other morbid conditions, with good results in terms of weight loss and control of the main metabolic parameters, at least in the short and medium term. According to the caloric content and the macronutrient composition, we can classify LCDs in hypocaloric, normoproteic diets [such as the Very Low-Calorie Ketogenic Diet (VLCKD) or the protein-sparing modified fasting (PSMF)], hypocaloric, hyperproteic and hyperlipidic diets (e.g., Atkins, Paleo diets…) and normocaloric, normo-/hyperproteic diets (eucaloric KD), the latter mainly used in patients with brain tumors (gliomas) and refractory epilepsy. In addition to LCD diets, another interesting dietary approach which gained attention in the last few decades is fasting and its beneficial effects in terms of modulation of metabolic pathways, cellular processes and hormonal secretions. Due to the impossibility of using fasting regimens for long periods of time, several alternative strategies have been proposed that can mimic the effects, including calorie restriction, intermittent or alternating fasting, and the so-called fasting mimicking diets (FMDs). Recent preclinical studies have shown positive effects of FMDs in various experimental models of tumors, diabetes, Alzheimer Disease, and other morbid conditions, but to date, the scientific evidence in humans is limited to some opens studies and case reports. The purpose of our narrative review is to offer an overview of the characteristics of the main dietary regimens applied in the treatment of different clinical conditions as well as of the scientific evidence that justifies their use, focusing on low and zero-carb diets and on the different types of fasting.

Effects of intermittent fasting on liver physiology and metabolism in mice

A broad spectrum of health benefits from intermittent fasting have been reported in studies on animal models and human subjects. However, the underlying mechanisms of these beneficial effects remain largely elusive. The present study aimed to explore the effects and potential mode of action of intermittent fasting in mouse models with a focus on the liver. C57BL/6 mice were subjected to intermittent fasting or ad libitum feeding as controls. It was determined that 12 h of daily intermittent fasting for 30 days significantly reduced the cumulative food intake compared with that in mice with ad libitum feeding. Fasting resulted in a significantly reduced liver mass but only had a minimal effect on bodyweight. The effects on the liver by 30 days of fasting were not reversed by subsequent ad libitum refeeding for 30 days. Among the measured blood biochemical parameters, the levels of blood glucose were decreased, while the levels of alkaline phosphatase were increased in fasting mice. Of note, targeted metabolic profiling revealed global elevation of metabolites in the livers of fasting mice. These metabolic molecules included adenosine triphosphate, nicotinamide adenine dinucleotide phosphate (NADP), reduced NADP and succinate, which are essentially involved in the citric acid cycle and oxidative phosphorylation. Thus, it was concluded that daily 12 h of intermittent fasting for one month significantly reduced the liver weight of mice, which is associated with enhanced liver metabolism.

Religious dietary rules and their potential nutritional and health consequences

BACKGROUND

The vast majority of the world population declares affiliation to a religion, predominantly Christianity and Islam. Many religions have special dietary rules, which may be more or less strictly adhered to.

METHODS

Religious food rules were collected from holy books and religious websites as well as their translation into dietary practices. The literature was searched for potential associations between these rules and potential nutritional consequences.

RESULTS

Jewish, Islamic and Indian religions support prolonged breastfeeding. Religious avoidance of alcohol is probably beneficial to health. When strictly applied, a few rules may lead to nutritional inadequacies, mainly in populations living in unfavourable socio-economic or environmental conditions. In Jewish and Muslim observants, animal slaughtering procedures may increase the risk of iron deficiency. Jews may be at risk of excess sodium intake related to home-prepared foods. A vegan diet, as observed by some believers, often by drifting from original precepts, or by some Hindus or Buddhists, may result in vitamin B12, calcium, iron, zinc, selenium and n-3 fatty acids deficiencies.

CONCLUSION

When implemented in accordance with the rules, most religious food precepts are not detrimental to health, as suggested by the fact that they have more or less been followed for millennia. Nevertheless, some practices may lead to nutritional inadequacies, such as iron, calcium, vitamin D and vitamin B12 deficiencies. Patients with low socio-economic status, children and women of childbearing age are of particular risk of such deficiencies. Being aware of them should help health professionals to take an individualized approach to decide whether to supplement or not.

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.

Effects of Ramadan Fasting on Physical Performance: A Systematic Review with Meta-analysis

BACKGROUND

It is common that several athletes will fast while training or competing during Ramadan. There is currently no consensus on if or how this might affect physical performance.

OBJECTIVE

The aim was to conduct a systematic review combined with a meta-analysis to determine what are the effects of fasting during the month of Ramadan on physical performance.

METHODS

Three electronic databases were searched: PubMed, ScienceDirect, and Web of Science between from the earliest available date to May 2019. Two authors identified studies that evaluated the effects of Ramadan fasting on physical performance. Risk of bias was assessed using the Downs and Black methodological quality checklist. Pooled effects were reported as standardized mean differences (MDs) and 95% confidence intervals (CIs) using a random effects model.

RESULTS

A total of 11 studies met the inclusion criteria. Results revealed that Ramadan fasting had a deleterious effect on mean power and peak power during a Wingate and/or a repeated sprint test. In the morning, sprint performance was negatively affected by Ramadan fasting. Aerobic performance, strength, jump height, fatigue index, and total work were not affected by the intermittent fasting during the month of Ramadan.

CONCLUSIONS

The majority of physical performance parameters were not influenced by Ramadan fasting when tested either in the morning or in the afternoon. Athletes appear able to participate in competition in a fasted state with little impact on physical performance. Sleep and nutrition opportunities should be optimized to minimize likelihood of accumulating fatigue.

Circadian clocks in the digestive system

Many molecular, physiological and behavioural processes display distinct 24-hour rhythms that are directed by the circadian system. The master clock, located in the suprachiasmatic nucleus region of the hypothalamus, is synchronized or entrained by the light-dark cycle and, in turn, synchronizes clocks present in peripheral tissues and organs. Other environmental cues, most importantly feeding time, also synchronize peripheral clocks. In this way, the circadian system can prepare the body for predictable environmental changes such as the availability of nutrients during the normal feeding period. This Review summarizes existing knowledge about the diurnal regulation of gastrointestinal processes by circadian clocks present in the digestive tract and its accessory organs. The circadian control of gastrointestinal digestion, motility, hormones and barrier function as well as of the gut microbiota are discussed. An overview is given of the interplay between different circadian clocks in the digestive system that regulate glucose homeostasis and lipid and bile acid metabolism. Additionally, the bidirectional interaction between the master clock and peripheral clocks in the digestive system, encompassing different entraining factors, is described. Finally, the possible behavioural adjustments or pharmacological strategies for the prevention and treatment of the adverse effects of chronodisruption are outlined.

Impact of Intermittent Fasting on Lipid Profile-A Quasi-Randomized Clinical Trial

Background: Sub-optimal HDL is a prognostic marker of cardiovascular disease. South Asia has a high prevalence of sub-optimal HDL compared to other parts of the world. Intermittent fasting (IF) is a type of energy restriction which may improve serum HDL and other lipids thereby reducing the risk of cardiovascular diseases.

Objective: The aim of the study was to evaluate the effect of IF on lipid profile and HDL-cholesterol in a sample of South Asian adults.

Methods: A 6-week quasi-experimental (non-randomized) clinical trial was conducted on participants with low HDL (< 40 mg/dl for men and < 50 mg/dl for women). Participants of the control group were recommended not to change their diet. The intervention group was recommended to fast for ~12 h during day time, three times per week for 6 weeks. Pulse rate, blood pressure, body weight, waist circumference, serum lipid profile, and blood glucose levels were measured at baseline and after 6 weeks.

Result: A total of 40 participants were enrolled in the study (N = 20 in each group), while 35 (20 control and 15 intervention) completed the trial and were included in data analysis of the study. Body measurements, including body weight, BMI and waist circumference, showed significant interaction effects (p's < 0.001), indicating that there were larger reductions in the IF group than in the control group. Significant interaction effects were also observed for total (p = 0.033), HDL (p = 0.0001), and LDL cholesterol (p = 0.010) with larger improvements in the IF group.

Conclusion: This study suggests that intermittent fasting may protect cardiovascular health by improving the lipid profile and raising the sub-optimal HDL. Intermittent fasting may be adopted as a lifestyle intervention for the prevention, management and treatment of cardiovascular disorders.

Clinical Trial Registration: NCT03805776, registered on January 16, 2019, https://clinicaltrials.gov/ct2/show/NCT03805776

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.

Does the Energy Restriction Intermittent Fasting Diet Alleviate Metabolic Syndrome Biomarkers? A Randomized Controlled Trial

The aim of this study was to determine the efficacy of an energy restriction intermittent fasting diet in metabolic biomarkers and weight management among adults with metabolic syndrome. This randomized controlled study was performed with metabolic syndrome patients, aged 18–65 years, at an academic institution in Istanbul, Turkey (n = 70). All participants were randomized to the Intermittent Energy Restriction (IER) intervention group and Continuous Energy Restriction (CER) control group. Biochemical tests including lipid profile, fasting plasma glucose, insulin, glycosylated hemoglobin Type A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), blood pressure, and body composition were evaluated at baseline and at the 12th week in diet interviews. Dietary intake was measured with the 24-h dietary recall method and dietary quality was evaluated with the Healthy Eating Index-2010. Changes in body weight (≈7% weight loss) and composition were similar in both groups. Blood pressure, total cholesterol, triglyceride, low-density lipoprotein (LDL), fasting glucose, and insulin at the 12th week decreased in both groups (p < 0.05). No significant differences were observed in metabolic syndrome biomarkers between the IER and CER groups. The energy-restricted intermittent fasting diet did not cause any deficiencies in macronutrient and fiber intake in the subjects. Healthy Eating Index (HEI) index scores were achieved similarly in both groups, and subjects’ dietary intakes were close to daily reference nutritional intake values. The technique used to achieve energy restriction, whether intermittent or continuous, appears to alleviate the metabolic syndrome biomarkers activated by weight loss.