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

Effect of Intermittent Fasting on Liver Function Tests: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

CONTEXT

Intermittent fasting (IF) is a diet strategy with alternate intervals of calorie reduction and normal eating. Despite its beneficial effects on weight loss and cardiometabolic risk factors, the effect of IF on liver function tests (LFTs) remains unclear.

OBJECTIVE

This study aimed to investigate the effect of IF on LFTs through a systematic review and meta-analysis of randomized clinical trials.

DATA SOURCES

An electronic search was performed using predefined search terms in databases including PubMed, Scopus, and ISI Web of Science until February 2023.

DATA EXTRACTION

The studies were selected according to PRISMA guidelines, and the risk of bias was assessed for the randomized controlled trials.

DATA ANALYSIS

The results of this study are reported as weighted mean differences (WMDs) with 95% CIs. Fourteen RCTs were included in the meta-analysis, with a total sample size of 908. IF significantly reduced alanine aminotransferase (ALT) (WMD: -2.88, 95% CI: -4.72 to -1.04, P-value = .002) and aspartate aminotransferase (AST) levels (WMD: -1.67, 95% CI: -3.12 to -0.22, P-value = .024). The results of the subgroup analysis showed that the impact of IF was significant in both the nonalcoholic fatty liver disease and the healthy groups for ALT. The effects of IF on the serum gamma-glutamyl transpeptidase (GGT) level were significant (WMD: -3.19, 95% CI: -6.00 to -0.39, P-value = .026), but there were no significant changes in the alkaline phosphatase (ALP) level (WMD: 1.06, 95% CI: -0.23 to 2.34, P-value = .106). Furthermore, no substantial heterogeneity between studies was reported.

CONCLUSION

IF can improve ALT, AST, and GGT levels but not ALP enzyme levels and may have a benefit on liver function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023396211.

The impact of intermittent fasting during Ramadan on psychomotor and cognitive skills in adolescent athletes

Introduction

Intermittent fasting (IF) represents a dietary intervention similar to caloric restriction, characterized by the strategic limitation of food consumption. Among the diverse array of practices for IF, Ramadan IF (RIF), a religious observance in Islam, mandates that healthy adult Muslims abstain from both food and drinks during daylight hours. In sports, researchers have extensively studied IF effects on health, including sleep and physical performance, but its impact on cognitive functions during RIF remains understudied. Therefore, this study was conducted to evaluate the influence of RIF on psychomotor and cognitive performance among young female athletes.

Methods

To achieve this purpose, a cohort of 23 female handball players, aged 17.2 ± 0.5 years, participated in a series of six testing sessions: one conducted prior to Ramadan (R0), and others during the first (R1), second (R2), third (R3), and fourth (R4) weeks of Ramadan, followed by a session in the week after Ramadan (R5). Each session involved assessments using a Simple Reaction Time Test (SRT), Choice Reaction Time Test (CRT), Vigilance Test (VT), and Mental Rotation Test (MRT). Additionally, dietary intake, body composition, and Pittsburgh Sleep Quality Index (PSQI) scores were evaluated during these periods.

Results and discussion

The obtained data illustrated that there was a decrease in SRT, CRT, VT, and MRT performances during R1 in comparison to R0 (all p < .001). This reduction was also observed in R2, R3, R4, and R5. Notably, during the fourth week of Ramadan (R4), these cognitive and psychomotor parameters were significantly lower than during the earlier weeks (R1, R2, R3; all p < .001). Furthermore, a gradual decrease in total PSQI scores, sleep quality, and sleep duration was observed throughout the Ramadan period, reaching the lowest levels during R4. These findings illustrate that RIF has a significantly detrimental impact on neuromuscular and cognitive abilities as well as sleep quality in young female athletes. The study also highlights a fluctuating pattern in cognitive function across the four weeks of Ramadan, with the most pronounced decline observed during the final week of fasting illustrating the importance of conducting similar studies on normal individuals from both genders with larger sample size.

Associations between exposure to phthalates and liver function among women undergoing assisted reproductive technology

Phthalates can induce hepatotoxicity in animal studies. We aimed to assess the associations of individual and mixture of urinary phthalate metabolites with serum liver function indicators among 764 women undergoing assisted reproductive technology (ART). In linear models, we observed inverse correlations between urinary mono-benzyl phthalate and serum total protein (TP) as well as globulin (β=-0.27 and -0.23, respectively, P<0.05). Additionally, negative associations were identified between mono-isobutyl phthalate and mono-butyl phthalate (MBP) and aspartate aminotransferase-to-alanine transaminase ratio (AST/ALT) (P<0.05). MBP and the sum of all phthalate metabolites (∑all.phth.m) were positively associated with bilirubin, with β ranging from 0.14 to 0.47. Most phthalate metabolites were also positively related to gamma-glutamyl transferase (GGT) (all P<0.05). In Bayesian kernel machine regression models, phthalate mixture was positively associated with bilirubin and GGT, whereas inversely associated with AST/ALT and TP. Our results suggest that phthalate exposure may impair liver function among women undergoing ART.

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).

Time-Restricted Feeding Attenuates Metabolic Dysfunction-Associated Steatohepatitis and Hepatocellular Carcinoma in Obese Male Mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) has surpassed the hepatitis B virus and hepatitis C virus as the leading cause of chronic liver disease in most parts of the Western world. MASLD (formerly known as NAFLD) encompasses both simple steatosis and more aggressive metabolic dysfunction-associated steatohepatitis (MASH), which is accompanied by inflammation, fibrosis, and cirrhosis, and ultimately can lead to hepatocellular carcinoma (HCC). There are currently very few approved therapies for MASH. Weight loss strategies such as caloric restriction can ameliorate the harmful metabolic effect of MASH and inhibit HCC; however, it is difficult to implement and maintain in daily life, especially in individuals diagnosed with HCC. In this study, we tested a time-restricted feeding (TRF) nutritional intervention in mouse models of MASH and HCC. We show that TRF abrogated metabolic dysregulation induced by a Western diet without any calorie restriction or weight loss. TRF improved insulin sensitivity and reduced hyperinsulinemia, liver steatosis, inflammation, and fibrosis. Importantly, TRF inhibited liver tumors in two mouse models of obesity-driven HCC. Our data suggest that TRF is likely to be effective in abrogating MASH and HCC and warrant further studies of time-restricted eating in humans with MASH who are at higher risk of developing HCC.

Effect of calorie restriction and intermittent fasting on glucose homeostasis, lipid profile, inflammatory, and hormonal markers in patients with polycystic ovary syndrome: a systematic review

Background and objective

Polycystic ovary syndrome (PCOS) is a complex hormonal disorder that leads to ovarian cysts, irregular ovulation, and hormonal swings in women. It is a complex and heterogeneous condition that affects 4 to 20% of women of reproductive age worldwide and relates to reproductive, metabolic, and psychosocial dysfunction. Dietary and lifestyle modifications have been proposed to play a central role in the management of PCOS. This study aimed to provide a comprehensive systemic overview of the existing literature on the effects of intermittent fasting (IF) and calorie restriction (CR) regimens on disease markers of PCOS.

Designs and methods

Several databases, such as CINAHL, Cochrane, EBSCOhost, EMBASE, Google Scholar, ProQuest Medical, PubMed/MEDLINE, ScienceDirect, Scopus, and Web of Science databases were searched for clinical trials and observational studies examined the effects of IF regimens such as time-restricted eating and Ramadan model of IF (RIF) on glucose homeostasis, lipid profile, inflammatory and hormonal markers in patients with PCOS.

Results

This systematic review solicited three articles, comprising a collective sample size of 75 females diagnosed with PCOS. The studies were published between 2015 to 2023 and were undertaken in three countries: China, Turkey, and Iran. The research articles examined the effects of intervention with IF and CR on PCOS-related parameters such as anthropometric measures and biochemical tests which included enzymes, glycemic control, lipid profile, hormonal, and oxidative stress, and inflammatory markers. The articles yielded mixed results, with two of them showing significant changes across all tested parameters. One of the three studies did not exhibit any significant changes.

Conclusion

Very limited studies examined the relationship between IR and CR with markers of PCOS. Further well-controlled studies need to be undertaken the combined results from the limited studies illustrate the intricate and diverse nature of IF, including the RIF, and its influence on measurements of body composition and biochemical markers related to PCOS.

Ramadan fasting model exerts hepatoprotective, anti-obesity, and anti-hyperlipidemic effects in an experimentally-induced nonalcoholic fatty liver in rats

BACKGROUND

The epidemic of nonalcoholic fatty liver disease (NAFLD) and its metabolic effects present a serious public health concern. We hypothesized that the Ramadan fasting model (RFM), which involves fasting from dawn to dusk for a month, could provide potential therapeutic benefits and mitigate NAFLD. Accordingly, we aimed to validate this hypothesis using obese male rats.

METHODS

Rats were split into two groups (n = 24 per group), and they were given either a standard (S) or high-fat diet (HFD) for 12 weeks. During the last four weeks of the study period, both S- and HFD-fed rats were subdivided into eight groups to assess the effect of RFM with/without training (T) or glucose administration (G) on the lipid profile, liver enzymes, and liver structure (n = 6/group).

RESULTS

The HFD+RFM group exhibited a significantly lower final body weight than that in the HFDC group. Serum cholesterol, low-density lipoprotein, and triglyceride levels were significantly lower in the HFD+RFM, HFD+RFM+T, and HFD+RFM+G groups than those in the HFDC group. Compared with the HFDC group, all groups had improved serum high-density lipoprotein levels. Furthermore, HFD groups subjected to RFM had reduced serum levels of aspartate transaminase and alanine transaminase compared with those of the HFD-fed group. Moreover, the liver histology improved in rats subjected to RFM compared with that of HFD-fed rats, which exhibited macro- and micro-fat droplet accumulation.

CONCLUSION

RFM can induce positive metabolic changes and improve alterations associated with NAFLD, including weight gain, lipid profile, liver enzymes, and hepatic steatosis.

Unlocking the Benefits of Fasting: A Review of its Impact on Various Biological Systems and Human Health

Fasting has gained significant attention in recent years for its potential health benefits in various body systems. This review aims to comprehensively examine the effects of fasting on human health, specifically focusing on its impact on different body's physiological systems. The cardiovascular system plays a vital role in maintaining overall health, and fasting has shown promising effects in improving cardiovascular health markers such as blood pressure, cholesterol levels, and triglyceride levels. Additionally, fasting has been suggested to enhance insulin sensitivity, promote weight loss, and improve metabolic health, thus offering potential benefits to individuals with diabetes and metabolic disorders. Furthermore, fasting can boost immune function, reduce inflammation, enhance autophagy, and support the body's defense against infections, cancer, and autoimmune diseases. Fasting has also demonstrated a positive effect on the brain and nervous system. It has been associated with neuroprotective properties, improving cognitive function, and reducing the risk of neurodegenerative diseases, besides the ability of increasing the lifespan. Hence, understanding the potential advantages of fasting can provide valuable insights for individuals and healthcare professionals alike in promoting health and wellbeing. The data presented here may have significant implications for the development of therapeutic approaches and interventions using fasting as a potential preventive and therapeutic strategy.

Inhibition of cGAS-STING pathway by stress granules after activation of M2 macrophages by human mesenchymal stem cells against drug induced liver injury

OBJECTIVE

Cells can produce stress granules (SGs) to protect itself from damage under stress. The cGAS-STING pathway is one of the important pattern recognition pathways in the natural immune system. This study was investigated whether human mesenchymal stem cells (hMSCs) could protect the liver by inducing M2 macrophages to produce SGs during acute drug induced liver injury (DILI) induced by acetaminophen (APAP).

METHODS

After intragastric administration of APAP in vivo to induce DILI mice model, hMSCs were injected into the tail vein. The co-culture system of hMSCs and M2 macrophages was established in vitro. It was further use SGs inhibitor anisomicin to intervene M2 macrophages. The liver histopathology, liver function, reactive oxygen species (ROS) level, apoptosis pathway, endoplasmic reticulum stress (ERS) level, SGs markers (G3BP1/TIA-1), cGAS-STING pathway, TNF-α, IL-6, IL-1β mRNA levels in liver tissue and M2 macrophages were observed.

RESULTS

In vivo experiments, it showed that hMSCs could alleviate liver injury, inhibite the level of ROS, apoptosis and ERS, protect liver function in DILI mice. The mount of M2 was increased in the liver. hMSCs could also induce the production of SGs, inhibit the cGAS-STING pathway and reduce TNF-α, IL-6, IL-1β mRNA expression. The results in vitro showed that hMSCs could induce the production of SGs in macrophages, inhibit the cGAS-STING pathway, promote the secretion of IL-4 and IL-13, and reduce TNF-α, IL-6, IL-1β mRNA level in cells. In the process of IL-4 inducing M2 macrophage activation, anisomycin could inhibit the production of SGs, activate the cGAS-STING pathway, and promote the inflammatory factor TNF-α, IL-6, IL-1β mRNA expression in cells.

CONCLUSIONS

HMSCs had a protective effect on acute DILI in mice induced by APAP. Its mechanism might involve in activating M2 type macrophages, promoting the production of SGs, inhibiting the cGAS-STING pathway, and reducing the expression of pro-inflammatory factors in macrophages, to reduce hepatocytes damage.

Reflection on Ramadan Fasting Research Related to Sustainable Development Goal 3 (Good Health and Well-Being): A Bibliometric Analysis

There is a large body of research on Ramadan intermittent fasting (RIF) and health in Muslim communities, that can offer insights to promote the achievement of Sustainable Development Goal 3 (SDG 3), which encompasses good health and well-being. Based on recent bibliometric evidence, we hypothesized that RIF research is highly relevant to SDG 3, particularly Targets 3.1, 3.2, 3.4, and 3.5. Therefore, this bibliometric study quantified RIF literature supporting SDG 3 and associated targets over the past seven decades and explored themes and trends. All types of research articles were extracted from the Scopus database from inception to March 2022. Microsoft Excel, Biblioshiny, and VOSviewer were used to qualitatively and quantitatively examine RIF research trends supporting SDG 3 and associated targets. We identified 1729 relevant articles. The number of publications notably increased since 1986, with a dramatic increase in 2019-2020. RIF research predominantly supported Target 3.4 (reducing risk for non-communicable diseases), with research hotspots being diabetes, diabetes medications, pregnancy, physiology, metabolic diseases, and obesity and metabolism. This target was also the most commonly supported by dedicated authors and institutions publishing on RIF, whereas other SDG 3 targets were negligibly addressed in comparison. Our comprehensive bibliometric analysis of RIF literature showed growing support for SDG 3 through positive contributions to half of the SDG 3 targets, although Target 3.4 received the most attention. We also identified knowledge gaps that may shape further research directions on RIF and promote the achievement of SDG 3 in Muslim communities.

Changes in energy and macronutrient intakes during Ramadan fasting: a systematic review, meta-analysis, and meta-regression

CONTEXT

Ramadan fasting (RF) is associated with various physiological and metabolic changes among fasting Muslims. However, it remains unclear whether these effects are attributable to changes in meal timing or changes in dietary energy and macronutrient intakes. Furthermore, the literature on the associations between RF, meal timing, and energy and macronutrient intakes is inconclusive.

OBJECTIVES

This systematic review aimed to estimate the effect sizes of RF on energy and macronutrient intakes (carbohydrates, protein, fats, dietary fiber, and water) and determine the effect of different moderators on the examined outcomes.

DATA SOURCES

The Cochrane, CINAHL, EMBASE, EBSCOhost, Google Scholar, PubMed/MEDLINE, ProQuest Medical, Scopus, ScienceDirect, and Web of Science databases were searched from inception to January 31, 2022.

DATA EXTRACTION

The studies that assessed energy, carbohydrate, protein, fat, fiber, and water intakes pre- and post-fasting were extracted.

DATA ANALYSIS

Of the 4776 identified studies, 85 relevant studies (n = 4594 participants aged 9-85 y) were selected. The effect sizes for the studied variables were as follows: energy (number of studies [K] = 80, n = 3343 participants; mean difference [MD]: -142.45; 95% confidence interval [CI]: -215.19, -69.71), carbohydrates (K = 75, n = 3111; MD: -23.90; 95% CI: -36.42, -11.38), protein (K = 74, n = 3108; MD: -4.21; 95% CI: -7.34, -1.07), fats (K = 73, n = 3058; MD: -2.03; 95% CI: -5.73, 1.67), fiber (K = 16, n = 1198; MD: 0.47; 95% CI: -1.44, 2.39), and water (K = 17, n = 772; MD: -350.80; 95% CI: -618.09, 83.50). Subgroup analyses showed age significantly moderated the 6 dietary outcomes, and physical activity significantly moderated water intake. There were significant reductions in energy, carbohydrate, and protein intakes during RF.

CONCLUSIONS

The change in meal timing rather than quantitative dietary intake may explain various physiological and health effects associated with RF.

The Impact of Intermittent Fasting on Non-Alcoholic Fatty Liver Disease in Older Adults: A Review of Clinicaltrials.gov Registry

Background

Non-alcoholic fatty liver disease (NAFLD) is a predominant health condition across the world due to its rising prevalence and association with various metabolic disorders. Intermittent fasting (IF) has attracted increasing attention as a dietary approach to addressing weight management and enhancing metabolic well-being, and its potential effects on NAFLD have been a topic of growing research interest.

Aim

This review aims to critically evaluate the current evidence on IF's impact on NAFLD, including the mechanisms underlying the observed effects in older adults (65+).

Methods

A comprehensive search of Clinicaltrials.gov was conducted to identify relevant studies that investigated the effects of IF on NAFLD in older adults (65+). Data on study design, sample size, intervention details, and outcomes related to NAFLD were extracted and analyzed.

Results

As of April 12th, 2023, there were 1304 clinical trials on NAFLD. Most of these were interventional studies. The investigation focused on completed studies and found that limited clinical trials were identified with limited interventional measures. Only five out of the 1304 studies on NAFLD involved IF. Basic and advanced outcome measures were examined.

Conclusion

Although some studies suggest that IF may have potential benefits for NAFLD, the evidence is still limited and inconclusive.

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.

β-hydroxybutyrate: A crucial therapeutic target for diverse liver diseases

β-hydroxybutyrate (β-HB), the most abundant ketone body, is produced primarily in the liver and acts as a substitute energy fuel to provide energy to extrahepatic tissues in the event of hypoglycemia or glycogen depletion. We now have an improved understanding of β-HB as a signal molecule and epigenetic regulatory factor as a result of intensive research over the last ten years. Because β-HB regulates various physiological and pathological processes, it may have a potential role in the treatment of metabolic diseases. The liver is the most significant metabolic organ, and the part that β-HB plays in liver disorders is receiving increasing attention. In this review, we summarize the therapeutic effects of β-HB on liver diseases and its underlying mechanisms of action. Moreover, we explore the prospects of exogenous supplements and endogenous ketosis including fasting, caloric restriction (CR), ketogenic diet (KD), and exercise as adjuvant nutritional therapies to protect the liver from damage and provide insights and strategies for exploring the treatment of various liver diseases.

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.

Sex as a biological determinant in anthropometric, biochemical, and dietary changes during Ramadan intermittent fasting in healthy people: A systematic review

AIMS

Observing Ramadan intermittent fasting (RIF) is associated with different behavioral, dietary, and health-related outcomes among healthy and unwell people. Sex is a major biological determinant that affects various health outcomes and impacts the effectiveness of dietary and lifestyle modifications. This systematic review aimed to identify differences in health-related outcomes following the practice of RIF by the sex of study participants.

METHODS

A systematic search was conducted across several databases to qualitatively identify studies focused on dietary, anthropometric, and biochemical outcomes associated with RIF in females and males.

RESULTS

Of 3870 retrieved studies, sex-based differences were reported in 29 studies that included 3167 healthy people (females n = 1558, 49.2%). Most differences between males and females were reported both before and during RIF. Sex differences were examined for 69 outcomes following RIF and included dietary factors (17 outcomes), anthropometrics (13 outcomes), and biochemical factors (39 outcomes), with the latter including metabolic, hormonal, regulatory, inflammatory, and nutrition-related biochemical markers.

CONCLUSIONS

Sex-based differences were observed in the examined dietary, anthropometric, and biochemical outcomes associated with the observance of RIF. More attention needs to be directed toward including both sexes in studies focused on the impact of observing RIF and differentiating outcomes based on sex.

Efficacy and safety of carnitine supplementation on NAFLD: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The efficacy and safety of L-carnitine supplementation on non-alcoholic fatty liver disease (NAFLD) are unclear. This systematic review and meta-analysis aimed to assess the efficacy and safety of L-carnitine supplementation on NAFLD.

METHODS

We searched in four databases (PubMed, Embase, Cochrane Library, and Web of Science) from inception to 1 November 2022 (updated on March 20, 2023) for potentially relevant records without language restrictions. We collected information on the first author, publication year, country, setting, study design, population characteristics, duration of follow-up, outcome variables of interest, and sources of funding. We used a modified Cochrane risk of bias tool to assess the risk of bias, used GRADE to assess the certainty of evidence, and used the Credibility of Effect Modification Analyses (ICEMAN) tool to assess the credibility of any apparent subgroup effect.

RESULTS

This systematic review and meta-analysis included eight eligible randomized controlled trials (RCTs). Compared to placebo, low certainty evidence show that L-carnitine supplementation significantly changes (reduced) more in AST levels and ALT levels (MD: - 26.38, 95%CI: - 45.46 to - 7.30), and moderate certainty evidence show that L-carnitine supplementation significantly changes (reduced) more in HDL cholesterol levels (MD: 1.14, 95%CI: 0.21 to 2.07) and triglyceride levels (MD: - 6.92, 95%CI: - 13.82 to - 0.03). Moderate credibility of ICEMAN results shows that L-carnitine supplementation has no difference in changes of AST and ALT levels in younger ones (MD: 0.5, 95%CI: - 0.70 to 1.70) but has significant changes (reduced) in adults (MD: - 20.3, 95%CI: - 28.62 to - 12.28) compared to placebo.

CONCLUSION

L-carnitine supplementation may improve liver function and regulate triglyceride metabolism in patients with NAFLD, and with no significant adverse effects.

Examination of sleep in relation to dietary and lifestyle behaviors during Ramadan: A multi-national study using structural equation modeling among 24,500 adults amid COVID-19

Background

Of around 2 billion Muslims worldwide, approximately 1.5 billion observe Ramadan fasting (RF) month. Those that observe RF have diverse cultural, ethnic, social, and economic backgrounds and are distributed over a wide geographical area. Sleep is known to be significantly altered during the month of Ramadan, which has a profound impact on human health. Moreover, sleep is closely connected to dietary and lifestyle behaviors.

Methods

This cross-sectional study collected data using a structured, self-administered electronic questionnaire that was translated into 13 languages and disseminated to Muslim populations across 27 countries. The questionnaire assessed dietary and lifestyle factors as independent variables, and three sleep parameters (quality, duration, and disturbance) as dependent variables. We performed structural equation modeling (SEM) to examine how dietary and lifestyle factors affected these sleep parameters.

Results

In total, 24,541 adults were enrolled in this study. SEM analysis revealed that during RF, optimum sleep duration (7-9 h) was significantly associated with sufficient physical activity (PA) and consuming plant-based proteins. In addition, smoking was significantly associated with greater sleep disturbance and lower sleep quality. Participants that consumed vegetables, fruits, dates, and plant-based proteins reported better sleep quality. Infrequent consumption of delivered food and infrequent screen time were also associated with better sleep quality. Conflicting results were found regarding the impact of dining at home versus dining out on the three sleep parameters.

Conclusion

Increasing the intake of fruits, vegetables, and plant-based proteins are important factors that could help improve healthy sleep for those observing RF. In addition, regular PA and avoiding smoking may contribute to improving sleep during RF.

Ramadan diurnal intermittent fasting is associated with significant plasma metabolomics changes in subjects with overweight and obesity: A prospective cohort study

Introduction

During the holy month of Ramadan, adult healthy Muslims are mandated to abstain from dawn to sunset, with free eating at night hours that may extend up to 12 h. The current work was designed to investigate the metabolomics changes incurred upon the observance of Ramadan diurnal intermittent fasting (RDIF).

Methods

Twenty-five metabolically healthy participants with overweight and obesity (7 females and 18 males, with a mean age of 39.48 ± 10.0 years) were recruited for the study and were followed before and at the end of RDIF month. Dietary, anthropometric, biochemical, and physical activity assessments were performed before and at the end of the fasting month. The metabolomic assay was performed using liquid chromatography-mass spectrometry for the two-time points.

Results and discussion

Metabolomics assay revealed a significant reduction in a few metabolites. The analysis revealed that 27 metabolites differed significantly (P < 0.05) between pre-and post-RDIF. Among the differentially abundant metabolites, 23 showed a decrease with fasting, these included several amino acids such as aspartame, tryptophan, phenylalanine, histidine, and other metabolites including valeric acid, and cortisol. On the other hand, only four metabolites showed increased levels after RDIF including traumatic acid, 2-pyrrolidinone, PC[18:1(9Z)/18:1(9Z)], and L-sorbose. The MetaboAnalyst^® platform reported that the top enriched metabolic pathways included: (1) histidine metabolism; (2) folate biosynthesis (3) phenylalanine, tyrosine, and tryptophan biosynthesis; (4) aminoacyltRNA biosynthesis; (5) caffeine metabolism; (6) vitamin B₆ metabolism; and several other pathways relating to lipid metabolisms such as arachidonic acid metabolism, glycerophospholipid metabolism, and linoleic acid metabolism. In conclusion, RDIF entails significant changes in various metabolic pathways that reflect different dietary and lifestyle behaviors practiced during the fasting month.

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.

Effects of the 5:2 intermittent fasting diet on non-alcoholic fatty liver disease: A randomized controlled trial

Background and aims

Dietary regimens are crucial in the management of non-alcoholic fatty liver disease (NAFLD). The effects of intermittent fasting (IF) have gained attention in this regard, but further research is warranted. Thus, we aimed to ascertain the overall effects of the 5:2 IF diet (5 days a week of normal food intake and 2 consecutive fasting days) in patients with NAFLD compared to a control group (usual diet).

Methods and results

A 12-week randomized controlled trial was performed to evaluate the effects of the 5:2 IF diet on anthropometric indices, body composition, liver indices, serum lipids, glucose metabolism, and inflammatory markers in patients with NAFLD. The IF group (n = 21) decreased body weight (86.65 ± 12.57–82.94 ± 11.60 kg), body mass index (30.42 ± 2.27–29.13 ± 1.95 kg/m²), waist circumference (103.52 ± 6.42–100.52 ± 5.64 cm), fat mass (26.64 ± 5.43–23.85 ± 5.85 kg), fibrosis (6.97 ± 1.94–5.58 ± 1.07 kPa), steatosis scores/CAP (313.09 ± 25.45–289.95 ± 22.36 dB/m), alanine aminotransferase (41.42 ± 20.98–28.38 ± 15.21 U/L), aspartate aminotransferase (34.19 ± 10.88–25.95 ± 7.26 U/L), triglycerides (171.23 ± 39.88–128.04 ± 34.88 mg/dl), high-sensitivity C-reactive protein (2.95 ± 0.62 −2.40 ± 0.64 mg/L), and cytokeratin-18 (1.32 ± 0.06–1.19 ± 0.05 ng/ml) values compared to the baseline and the end of the control group (n = 23)—p ≤ 0.05 were considered as significant. However, the intervention did not change the levels of high-density lipoprotein cholesterol, total cholesterol, low-density lipoprotein cholesterol, fasting blood sugar, insulin, HOMA-IR, and total antioxidant capacity.

Conclusion

Adhering to the 5:2 IF diet can reduce weight loss and related parameters (fat mass and anthropometric indicators of obesity), as well as hepatic steatosis, liver enzymes, triglycerides, and inflammatory biomarkers in patients with NAFLD.

Seven decades of Ramadan intermittent fasting research: Bibliometrics analysis, global trends, and future directions

BACKGROUND AND AIMS

There is a large body of research focused on various aspects related to Ramadan intermittent fasting (RIF) and human health and disease. This study aimed to quantify the bibliometric data of RIF medical research over the past seven decades and explore these variables qualitatively via text mining analysis.

METHODS

We used the Scopus search engine to identify published articles related to RIF from inception to December 31, 2021. All types of research articles were included. Scientometric and bibliometric measures were determined using Excel, Biblioshiny, and VOSviewer. This study proposed a bibliometric and text mining method to qualitatively and quantitatively recognize the RIF research trend.

RESULTS

The Scopus search returned 1915 relevant articles. Most citations pertained to publications from the last two decades, and most publications were original research articles. These publications had received around 27,000 citations, and the 20 most prolific publishing journals had an average h-index of 112.25. More than one-third of all medical publications were in open-access journals. There was a 13-fold increase in medical research on RIF over the past few decades. We identified the 10 most prolific publishing countries, institutes, journals, and authors. We also identified five scientific hotspots of RIF scientific literature, which were: diabetes, metabolic health, public health, physiology, and maternity.

CONCLUSION

This is the first comprehensive bibliometric analysis of medical research related to RIF. The research gaps identified will shape future research directions and foster collaborative research activities toward enhanced medical nutrition research revolving around RIF.

Haptoglobin polymorphism modulates cardiometabolic impacts of four consecutive weeks, dawn to sunset Ramadan intermittent fasting among subjects with overweight/obesity

AIMS

Haptoglobin (Hp) is a multifaceted marker of inflammation, and mediates the interplay between obesity, inflammation, and cardiometabolic dysfunction. However, the role of the Hp phenotype in modulating intermittent fasting (IF)-induced cardiometabolic changes remains to be elucidated.

METHODS

Hp phenotype was determined for the study subjects. Cardiometabolic markers were assessed before and at the end of four consecutive weeks, dawn to sunset IF.

RESULTS

A total of 114 subjects (75 males and 39 females, 38.7 ± 11.7 years, body mass index (BMI) of 30.41 ± 5.09 kg/m²) were recruited. Hp2-2 (n = 55, 48.2 %) and Hp2-1 (n = 53, 46.5 %) were the predominant phenotypes. Significant reductions were observed in serum Hp, IL-6, TNF-α, triglycerides (TG), total cholesterol (TC), LDL, BMI, and fat mass (FM), while a significant elevation was observed in serum CD163, HDL, and IL-10 at the end of the IF month for the whole population. Based on the Hp polymorphism, significant decreases in Hp, BMI, FM, TG, LDL, and TNF-α, with significant increases in HDL and CD163 levels were observed among subjects with Hp2-2 and Hp2-1 phenotypes. A more pronounced reduction in FM was reported in subjects with Hp2-2 in comparison with Hp2-1.

CONCLUSION

Hp gene polymorphism modulates IF-induced changes in cardiometabolic markers.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN18205186; https://trialsearch.who.int/?TrialID=ISRCTN18205186.

Bibliometric overview of Ramadan fasting studies during 2010-2021

BACKGROUND AND AIMS

To quantify the bibliometric parameters of Ramadan fasting literature from 2010 to 2021.

MATERIALS AND METHODS

Scopus was searched for all articles related to Ramadan fasting or Islamic fasting from the beginning of 2010 to the end of 2021. Only original articles and reviews were included and their bibliometric and scientometric parameters were determined using Excel, Graph Pad Prism, VOSviewer, and Sci2 tool software.

RESULTS

Finally 1276 articles, including 1109 original articles and 167 reviews, were included. These articles had 14263 citations and an H-index of 48. Based on the number of publications, top institute, top journal, top country, and top authors were University of Sfax (n = 48 articles), Diabetes Research and Clinical Practice (n = 69), the United States (n = 144), and Chtourou H & Hassanein M (n = 38), respectively. Also, Diabetes Research and Clinical Practice had a strong bibliographic coupling with other journals. The recent bursting words were adrenal insufficiency and COVID-19. The most co-occurred topics were the effect of Ramadan fasting on diabetic patients, pregnant women, and glycemic state and body composition of diabetic patients.

CONCLUSION

This study provided a comprehensive bibliometric overview of Ramadan fasting literature from 2010 to 2021. The temporal change in the number of publications and other analyses on the literature of 2019, 2020 and 2021 showed that substantial increasing publications with new emerging subjects had become of interest to many researchers during the last three years.

Sex as a Biological Factor in the Changes in Disease Patients During Ramadan Intermittent Fasting: A Systematic Review

Background

During Ramadan, many patients with diabetes, renal, cardiovascular, gastrointestinal diseases, headaches, and epilepsy choose to fast even against their doctor's advice. The impact of this intermittent fasting on health and disease could be different in men and women. The aim of this study was to determine the effect of sex as a factor in diseases outcomes of patients who opt to fast during Ramadan.

Main Body

The articles included in this study reported data on six diseases: diabetes, renal, cardiovascular, gastrointestinal diseases, headaches, and epilepsy. A systematic search was performed on PubMed and Scopus for observational and clinical studies mentioning Ramadan, diabetes, renal, cardiovascular, gastrointestinal diseases, headaches, and epilepsy in both men and women. Data was extracted by two independent reviewers using a standardized data-collection form. From 381 original articles, 38 studies were selected, including 25,023 patients of which 44.4% were women. Sex-based differences were reported by 18 studies for several variables such as body mass index, blood glucose, the frequency of hypoglycemia, renal colic, mortality, thrombosis, and gastrointestinal diseases in patients fasting during Ramadan. Most of the differences between men and women were reported both in the baseline period before Ramadan and during Ramadan. Indeed, during the period outside Ramadan, the frequency of renal colic, cardiovascular, gastrointestinal diseases, were higher in men; while body mass index, Thrombosis, and headache were higher in women. In the remaining 21 studies, it was reported that the sex factor was not associated with the effect of Ramadan fasting in the frequency and other outcomes of these diseases.

Conclusion

Currently, small attention is paid to sex as a determinant factor in patients while fasting during Ramadan. There appeared to be differences in the frequency and incidence of diseases in men and women during Ramadan. Closer attention to sex differences regarding the frequency and the progression of the diseases during fasting may help to improve patient care, especially to benefit those patients willing to fast during Ramadan.

Ramadan Fasting in Health and Disease in 2021: A Narrative Review

Introduction: The literature on the health aspects of Ramadan fasting (RF) is widely spread in many journals.

Materials and Methods: This is a narrative review of data obtained from the PubMed database (National Library of Medicine, Bethesda, Maryland, United States). We used the search term “Ramadan fasting,” and relevant records were examined. The publications are narrated thematically.

Results: The publications spanned fundamental, clinical, professional, cultural, and advocacy facets. The publications crossed conventional disciplinary lines and geographical locations and appeared in journals with different access systems. The contents are presented under the themes that emerged depending on the retrieved literature. This year basic coverage included changes in physiology and nutrition during Ramadan. However, the clinical issues included a wide range of topics. These included the impact of RF on nonalcoholic fatty liver disease and adjustments needed in endocrine replacement therapy for hypothyroidism and adrenal insufficiency. Coverage also included chronic kidney disease. The impact on maternal health, fetal well-being, and long-term effects of RF exposures were addressed in several studies. Studies in cardiovascular medicine focused on blood pressure and cardiovascular risk factors. Sports medicine and athletes' well-being received somewhat prominent coverage. The impact on renal function, particularly in patients with chronic kidney disease, was investigated by a few authors. Several groups addressed the eyes' structure and function, neurological conditions, especially headache disorders, and hematological and oncological conditions. Finally, the impact of RF on several aspects of mental health and well-being was addressed by various groups.

Conclusions: Health aspects of RF received a sustained academic interest with a broad spectrum in 2021. This narration provides an overview of the year's scholarly health-related literature on various aspects of health and disease. It should help researchers and clinicians catch up quickly with the health concerns during Ramadan.

Effect of Ramadan intermittent fasting on inflammatory markers, disease severity, depression, and quality of life in patients with inflammatory bowel diseases: A prospective cohort study

Background

Intermittent fasting (IF) during the month of Ramadan is part of the religious rituals of Muslims. The effect of intermittent fasting on disease activity in inflammatory bowel diseases (IBD) is still unknown. This is the first study to assess the effect of IF during Ramadan on inflammatory markers in patients diagnosed with IBD. The effects on clinical disease activity, quality of life, and levels of depression were also assessed.

Methods

Patients diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) who intended to observe Ramadan fasting were recruited. The following were assessed immediately before and at the end of Ramadan: Serum CRP and stool calprotectin, partial Mayo score, Harvey Bradshaw index (HBI), Simple IBD questionnaire (SIBDQ), and Hamilton depression scale questionnaire.

Results

80 patients diagnosed with IBD were recruited (60 UC, 20 CD). Serum CRP and stool calprotectin did not show a significant change before vs after fasting (median CRP 0.53 vs 0.50, P value = 0.27, Calprotectin 163 vs 218 respectively, P value = 0.62). The partial Mayo score showed a significant rise after fasting (median 1 before vs 1 after fasting, mean: 1.79 vs 2.33 respectively, P value = 0.02). Harvey-Bradshaw index did not show a significant change after fasting (median 4 vs 5, P value = 0.4). Multiple linear regression revealed that older age and a higher baseline calprotectin were associated with a higher change in Mayo score after fasting (P value = 0.02 and P value = 0.01, respectively). No significant change was detected in SIBDQ or Hamilton depression scale scores.

Conclusions

In patients diagnosed with UC, IF during Ramadan was associated with worsening of clinical parameters, the effect was more pronounced in older patients and those with higher baseline calprotectin levels. However, IF during Ramadan was not associated with an adverse effect on objective inflammatory markers (CRP and calprotectin).

Ramadan Intermittent Fasting Is Associated with Changes in Circulating Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in Metabolically Healthy Obese Subjects

Background and Objectives: Dietary modification is the principal approach to the management of hyperlipidemia in adults. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of plasma cholesterol and a target for novel lipid-lowering pharmacotherapies. This study aimed to explore how circulating levels of PCSK9 changed during Ramadan intermittent fasting in metabolically healthy obese subjects. Materials and Methods: This cross-sectional study used convenience sampling to recruit 55 overweight and obese participants (22 females and 33 males) who observed Ramadan fasting. Body weight and composition, glucoregulatory factors, serum PCSK9 concentration, dietary intake, and physical activity were assessed 1 week before and at the end of Ramadan fasting. Results: The median (interquartile range) age was 35 (22) years, and body mass index was 30.2 (5.4). We found significant (p < 0.05) increases in serum levels of PCSK9, serum insulin, insulin resistance, and leptin at the end of Ramadan compared with pre-fasting levels. Significant (p < 0.05) reductions in body weight, waist circumference, systolic and diastolic blood pressure, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and adiponectin were also observed at the end of Ramadan. Conclusions: Observing Ramadan fasting was associated with increased PCSK9 levels in metabolically healthy obese subjects. The complex relationships between PCSK9 and insulin resistance and dysregulation of adipokine secretion in relation to dietary and lifestyle modifications during Ramadan warrant further research.

Ramadan Diurnal Intermittent Fasting Is Associated With Attenuated FTO Gene Expression in Subjects With Overweight and Obesity: A Prospective Cohort Study

Aim and Background

A growing body of evidence supports the impact of intermittent fasting (IF) on normalizing body weight and that the interaction between body genes and environmental factors shapes human susceptibility to developing obesity. FTO gene is one of these genes with metabolic effects related to energy metabolism and body fat deposition. This research examined the changes in FTO gene expression upon Ramadan intermittent fasting (RIF) in a group of metabolically healthy subjects with overweight and obesity.

Methods

Sixty-three (63) subjects were recruited, of which 57 (17 males and 40 females, mean age 38.4 ± 11.2 years) subjects with overweight and obesity (BMI = 29.89 ± 5.02 kg/m2were recruited and monitored before and at the end of Ramadan month), and 6 healthy subjects with normal BMI (21.4 ± 2.20 kg/m2) recruited only to standardize the reference for normal levels of FTO gene expression. In the two-time points, anthropometric, biochemical, and dietary assessments were undertaken, and FTO gene expression tests were performed using RNA extracted from the whole blood sample.

Results

In contrast to normal BMI subjects, the relative gene expressions in overweight/obese were significantly decreased at the end of Ramadan (−32.30%, 95% CI–0.052 −0.981) in comparison with the pre-fasting state. Significant reductions were found in body weight, BMI, fat mass, body fat percent, hip circumference, LDL, IL-6, TNF-α (P&lt;0.001), and in waist circumference (P&lt;0.05), whilst HDL and IL-10 significantly increased (P&lt;0.001) at the end of Ramadan in comparison with the pre-fasting levels. Binary logistic regression analysis for genetic expressions showed no significant association between high-energy intake, waist circumference, or obesity and FTO gene expression.

Conclusions

RIF is associated with the downregulation of the FTO gene expression in subjects with obesity, and this may explain, at least in part, its favorable metabolic effects. Hence, RIF presumably may entail a protective impact against body weight gain and its adverse metabolic-related derangements in subjects with obesity.

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.