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

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.

The melanocortin-4 receptor pathway and the emergence of precision medicine in obesity management

Over the past few decades, there has been a global surge in the prevalence of obesity, rendering it a globally recognized epidemic. Contrary to simply being a medical condition, obesity is an intricate disease with a multifactorial aetiology. Understanding the precise cause of obesity remains a challenge; nevertheless, there seems to be a complex interplay among biological, psychosocial and behavioural factors. Studies on the genetic factors of obesity have revealed several pathways in the brain that play a crucial role in food intake regulation. The best characterized pathway, thus far, is the leptin-melanocortin pathway, from which disruptions are responsible for the majority of monogenic obesity disorders. The effectiveness of conservative lifestyle interventions in addressing monogenic obesity has been limited. Therefore, it is crucial to complement the management strategy with pharmacological and surgical options. Emphasis has been placed on developing drugs aimed at replacing the absent signals, with the goal of restoring the pathway. In both monogenic and polygenic forms of obesity, outcomes differ across various interventions, likely due to the multifaceted nature of the disease. This underscores the need to explore alternative therapeutic strategies that can mitigate this heterogeneity. Precision medicine can be regarded as a powerful tool that can address this concern, as it values the understanding of the underlying abnormality triggering the disease and provides a tailored treatment accordingly. This would assist in optimizing outcomes of the current therapeutic approaches and even aid in the development of novel treatments capable of more effectively managing the global obesity epidemic.

Fat mass and obesity-associated (FTO) gene is essential for insulin secretion and β-cell function: In vitro studies using INS-1 cells and human pancreatic islets

AIMS

In this study, we investigated the role of the FTO gene in pancreatic β-cell biology and its association with type 2 diabetes (T2D). To address this issue, human pancreatic islets and rat INS-1 (832/13) cells were used to perform gene silencing, overexpression, and functional analysis of FTO expression; levels of FTO were also measured in serum samples obtained from diabetic and obese individuals.

RESULTS

The findings revealed that FTO expression was reduced in islets from hyperglycemic/diabetic donors compared to normal donors. This reduction correlated with decreased INS and GLUT1 expression and increased PDX1, GCK, and SNAP25 expression. Silencing of Fto in INS-1 cells impaired insulin release and mitochondrial ATP production and increased apoptosis in pro-apoptotic cytokine-treated cells. However, glucose uptake and reactive oxygen species production rates remained unaffected. Downregulation of key β-cell genes was observed following Fto-silencing, while Glut2 and Gck were unaffected. RNA-seq analysis identified several dysregulated genes involved in metal ion binding, calcium ion binding, and protein serine/threonine kinase activity. Furthermore, our findings showed that Pdx1 or Mafa-silencing did not influence FTO protein expression. Overexpression of FTO in human islets promoted insulin secretion and upregulated INS, PDX1, MAFA, and GLUT1 expression. Serum FTO levels did not significantly differ between individuals with diabetes or obesity and their healthy counterparts.

CONCLUSION

These findings suggest that FTO plays a crucial role in β-cell survival, metabolism, and function and point to a potential therapeutic utility of FTO in T2D patients.

Effect of Calorie Restriction and Intermittent Fasting Regimens on Brain-Derived Neurotrophic Factor Levels and Cognitive Function in Humans: A Systematic Review

Background: The potential positive interaction between intermittent fasting (IF) and brain-derived neurotrophic factor (BDNF) on cognitive function has been widely discussed. This systematic review tried to assess the efficacy of interventions with different IF regimens on BDNF levels and their association with cognitive functions in humans. Interventions with different forms of IF such as caloric restriction (CR), alternate-day fasting (ADF), time-restricted eating (TRE), and the Ramadan model of intermittent fasting (RIF) were targeted. Methods: A systematic review was conducted for experimental and observational studies on healthy people and patients with diseases published in EMBASE, Scopus, PubMed, and Google Scholar databases from January 2000 to December 2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statements (PRISMA) for writing this review. Results: Sixteen research works conducted on healthy people and patients with metabolic disorders met the inclusion criteria for this systematic review. Five studies showed a significant increase in BDNF after the intervention, while five studies reported a significant decrease in BDNF levels, and the other six studies showed no significant changes in BDNF levels due to IF regimens. Moreover, five studies examined the RIF protocol, of which, three studies showed a significant reduction, while two showed a significant increase in BDNF levels, along with an improvement in cognitive function after RIF. Conclusions: The current findings suggest that IF has varying effects on BDNF levels and cognitive functions in healthy, overweight/obese individuals and patients with metabolic conditions. However, few human studies have shown that IF increases BDNF levels, with controversial results. In humans, IF has yet to be fully investigated in terms of its long-term effect on BDNF and cognitive functions. Large-scale, well-controlled studies with high-quality data are warranted to elucidate the impact of the IF regimens on BDNF levels and cognitive functions.

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.

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.

Eating, diet, and nutrition for the treatment of non-alcoholic fatty liver disease

Nutrition and dietary interventions are a central component in the pathophysiology, but also a cornerstone in the management of patients with non-alcoholic fatty liver disease (NAFLD). Summarizing our rapidly advancing understanding of how our diet influences our metabolism and focusing on specific effects on the liver, we provide a comprehensive overview of dietary concepts to counteract the increasing burden of NAFLD. Specifically, we emphasize the importance of dietary calorie restriction independently of the macronutrient composition together with adherence to a Mediterranean diet low in added fructose and processed meat that seems to exert favorable effects beyond calorie restriction. Also, we discuss intermittent fasting as a type of diet specifically tailored to decrease liver fat content and increase ketogenesis, awaiting future study results in NAFLD. Finally, personalized dietary recommendations could be powerful tools to increase the effectiveness of dietary interventions in patients with NAFLD considering the genetic background and the microbiome, among others.

Precision Nutrition: Recent Advances in Obesity

"Precision nutrition" is an emerging area of nutrition research that focuses on understanding metabolic variability within and between individuals and helps develop customized dietary plans and interventions to maintain optimal individual health. It encompasses nutritional genomic (gene-nutrient interactions), epigenetic, microbiome, and environmental factors. Obesity is a complex disease that is affected by genetic and environmental factors and thus a relevant target of precision nutrition-based approaches. Recent studies have shown significant associations between obesity phenotypes (body weight, body mass index, waist circumference, and central and regional adiposity) and genetic variants, epigenetic factors (DNA methylation and noncoding RNA), microbial species, and environment (sociodemographics and physical activity). Additionally, studies have also shown that the interactions between genetic variants, microbial metabolites, and epigenetic factors affect energy balance and adiposity. These include variants in FTO, MC4R, PPAR, APOA, and FADS genes, DNA methylation in CpG island regions, and specific miRNAs and microbial species such as Firmicutes, Bacteriodes, Clostridiales, etc. Similarly, studies have shown that microbial metabolites, folate, B-vitamins, and short-chain fatty acids interact with miRNAs to influence obesity phenotypes. With the advent of next-generation sequencing and analytical approaches, the advances in precision nutrition have the potential to lead to new paradigms, which can further lead to interventions or customized treatments specific to individuals or susceptible groups of individuals. This review highlights the recent advances in precision nutrition as applied to obesity and projects the importance of precision nutrition in obesity and weight management.

Genetics, genomics, and diet interactions in obesity in the Latin American environment

Obesity is a chronic disease characterized by abnormal or excessive fat accumulation that could impact an individual's health; moreover, the World Health Organization (WHO) has declared obesity a global epidemic since 1997. In Latin America, in 2016, reports indicated that 24.2% of the adult population was obese. The environmental factor or specific behaviors like dietary intake or physical activity have a vital role in the development of a condition like obesity, but the interaction of genes could contribute to that predisposition. Hence, it is vital to understand the relationship between genes and disease. Indeed, genetics in nutrition studies the genetic variations and their effect on dietary response; while genomics in nutrition studies the role of nutrients in gene expression. The present review represents a compendium of the dietary behaviors in the Latin American environment and the interactions of genes with their single nucleotide polymorphisms (SNPs) associated with obesity, including the risk allele frequencies in the Latin American population. Additionally, a bibliographical selection of several studies has been included; these studies examined the impact that dietary patterns in Latin American environments have on the expression of numerous genes involved in obesity-associated metabolic pathways.

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.

Time-Restricted Eating Regimen Differentially Affects Circulatory miRNA Expression in Older Overweight Adults

Time-restricted eating (TRE), a popular form of intermittent fasting, has been demonstrated to provide multiple health benefits, including an extension of healthy lifespan in preclinical models. While the specific mechanisms remain elusive, emerging research indicates that one plausible mechanism through which TRE may confer health benefits is by influencing the expression of the epigenetic modulator circulatory miRNAs, which serve as intercellular communicators and are dysregulated in metabolic disorders, such as obesity. Therefore, the goal of this pilot study is to examine the effects of a 4-week TRE regimen on global circulatory miRNA from older (≥65 years) overweight participants. Pre- and post-TRE regimen serum samples from nine individuals who participated in the Time to Eat clinical trial (NCT03590847) and had a significant weight loss (2.6 kg, p < 0.01) were analyzed. The expressions of 2083 human miRNAs were quantified using HTG molecular whole transcriptome miRNA assay. In silico analyses were performed to determine the target genes and biological pathways associated with differentially expressed miRNAs to predict the metabolic effects of the TRE regimen. Fourteen miRNAs were differentially expressed pre- and post-TRE regimen. Specifically, downregulated miRNA targets suggested increased expression of transcripts, including PTEN, TSC1, and ULK1, and were related to cell growth and survival. Furthermore, the targets of downregulated miRNAs were associated with Ras signaling (cell growth and proliferation), mTOR signaling (cell growth and protein synthesis), insulin signaling (glucose uptake), and autophagy (cellular homeostasis and survival). In conclusion, the TRE regimen downregulated miRNA, which, in turn, could inhibit the pathways of cell growth and activate the pathways of cell survival and might promote healthy aging. Future mechanistic studies are required to understand the functional role of the miRNAs reported in this study.