Metabolic Effects of Intermittent Fasting

Therapeutic potential of the ketogenic diet: A metabolic switch with implications for neurological disorders, the gut-brain axis, and cardiovascular diseases

The Ketogenic Diet (KD) is a dietary regimen that is low in carbohydrates, high in fats, and contains adequate protein. It is designed to mimic the metabolic state of fasting. This diet triggers the production of ketone bodies through a process known as ketosis. The primary objective of KD is to induce and sustain ketosis, which has been associated with numerous health benefits. Recent research has uncovered promising therapeutic potential for KD in the treatment of various diseases. This includes evidence of its effectiveness as a dietary strategy for managing intractable epilepsy, a form of epilepsy that is resistant to medication. We are currently assessing the efficacy and safety of KD through laboratory and clinical studies. This review focuses on the anti-inflammatory properties of the KD and its potential benefits for neurological disorders and the gut-brain axis. We also explore the existing literature on the potential effects of KD on cardiac health. Our aim is to provide a comprehensive overview of the current knowledge in these areas. Given the encouraging preliminary evidence of its therapeutic effects and the growing understanding of its mechanisms of action, randomized controlled trials are warranted to further explore the rationale behind the clinical use of KD. These trials will ultimately enhance our understanding of how KD functions and its potential benefits for various health conditions. We hope that our research will contribute to the body of knowledge in this field and provide valuable insights for future studies.

Effects of Intermittent Fasting on Female Reproductive Function: A Review of Animal and Human Studies

PURPOSE OF REVIEW

Intermittent fasting has gained significant attention, yet a comprehensive understanding of its impact on female reproductive health is lacking. This review aims to fill this gap by examining various intermittent fasting regimens and their effects on female reproductive function, along with potential mechanisms.

RECENT FINDINGS

In healthy non-overweight/obese or pregnant animal models, alternate-day fasting (ADF) and an 8-h time-restricted feeding (TRF) window may have adverse effects on reproductive function. However, these regimens show potential to mitigate negative consequences induced by a high-fat diet (HFD) or environmental exposure. A 10-h TRF demonstrates benefits in improving fertility in both normal-weight and HFD-fed animal models. In women with overweight/obesity or polycystic ovary syndrome (PCOS), the 5:2 diet and TRF significantly reduce the free androgen index while elevating sex hormone binding globulin, promising improvements in menstrual regulation. For pregnant Muslim women, available data do not strongly indicate adverse effects of Ramadan fasting on preterm delivery, but potential downsides to maternal weight gain, neonatal birthweight, and long-term offspring health need consideration. Factors linking intermittent fasting to female reproductive health include the circadian clock, gut microbiota, metabolic regulators, and modifiable lifestyles. Drawing definitive conclusions remains challenging in this evolving area. Nonetheless, our findings underscore the potential utility of intermittent fasting regimens as a therapeutic approach for addressing menstruation irregularities and infertility in women with obesity and PCOS. On the other hand, pregnant women should remain cognizant of potential risks associated with intermittent fasting practices.

The Reduction of Imidazole Propionate induced by Intermittent Fasting Promotes Recovery of Peripheral Nerve Injury by Enhancing Migration of Schwann Cells

Peripheral nerve injury (PNI) accompanied with sensory and motor dysfunction has serious effect on the quality of life of patients. Intermittent fasting (IF), as a dietary pattern, has rarely been reported to influence imidazole propionate (ImP), a microbial metabolite, in vivo. To date, the link between ImP and PNI is unknown. This study aimed to explore the impact of ImP on the recovery after PNI and determine whether IF could reduce the concentration of ImP in vivo. Sciatic nerve injury rat model and RSC96 cells were utilized with 16s RNA seq, HE staining, CCK-8 assay, Western blot (WB), Transmission electron microscopy (TEM), immunofluorescence, transwell and scratch wound healing assays as read outs. WB, TEM, transwell and wound healing assay showed an inhibitory effect of ImP on autophagy and migration of Schwann cells. This negative effect on migration was reversed by rapamycin. Detection of p-Erk and p-mTOR confirmed that the MAPK/Erk/mTOR pathway was involved in this process. In vivo, IF changed the composition of gut microbiome, including bacteria related to ImP production and reduced the concentration of ImP in serum. In sum, IF influenced the composition of gut microbiome and reduced the concentration of ImP in vivo. The reduction of ImP promoted migration of SCs through enhancing autophagy which involved MAPK/Erk/mTOR pathway.

Every-other-day fasting inhibits pyroptosis while regulating bile acid metabolism and activating TGR5 signaling in spinal cord injury

Every-other-day fasting (EODF) is a form of caloric restriction that alternates between periods of normal eating and fasting, aimed at preventing and treating diseases. This approach has gained widespread usage in basic research on neurological conditions, including spinal cord injury, and has demonstrated significant neuroprotective effects. Additionally, EODF is noted for its safety and feasibility, suggesting broad potential for application. This study aims to evaluate the therapeutic effects of EODF on spinal cord injury and to investigate and enhance its underlying mechanisms. Initially, the SCI rat model was utilized to evaluate the effects of EODF on pathological injury and motor function. Subsequently, considering the enhancement of metabolism through EODF, bile acid metabolism in SCI rats was analyzed using liquid chromatography-mass spectrometry (LC-MS), and the expression of the bile acid receptor TGR5 was further assessed. Ultimately, it was confirmed that EODF influences the activation of microglia and NLRP3 inflammasomes associated with the TGR5 signaling, along with the expression of downstream pyroptosis pathway related proteins and inflammatory cytokines, as evidenced by the activation of the NLRP3/Caspase-1/GSDMD pyroptosis pathway in SCI rats. The results demonstrated that EODF significantly enhanced the recovery of motor function and reduced pathological damage in SCI rats while controlling weight gain. Notably, EODF promoted the secretion of bile acid metabolites, activated TGR5, and inhibited the NLRP3/Caspase-1/GSDMD pyroptosis pathway and inflammation in these rats. In summary, EODF could mitigate secondary injury after SCI and foster functional recovery by improving metabolism, activating the TGR5 signaling and inhibiting the NLRP3 pyroptosis pathway.

Effects of Different Caloric Restriction Patterns on Blood Pressure and Other Cardiovascular Risk Factors: A Systematic Review and Network Meta-Analysis of Randomized Trials

CONTEXT

All types of caloric restriction are preventive against cardiovascular risk factors, but the best restriction method and most affected factors have not been identified.

OBJECTIVE

The objective of this study was to explore the effects of different caloric restriction methods on various cardiovascular risk factors by horizontally comparing program advantages and disadvantages via network meta-analysis.

DATA SOURCES

The PubMed, Web of Science, Cochrane Library, and Embase literature databases were searched (October 2013 to October 2023).

DATA EXTRACTION

Eligible randomized controlled trials involving participants who underwent caloric restriction and systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and high-density lipoprotein (HDL) cholesterol level measurements were included.

DATA ANALYSIS

Thirty-six of 13 208 records (0.27%) were included. Two researchers reviewed the articles, extracted data, and assessed article quality.

RESULTS

Alternate-day fasting (ADF) reduced SBP (4.88 mmHg; CI, 2.06-7.15) and DBP (5.10 mmHg; CI, 2.44-7.76). Time-restricted eating reduced SBP (2.46 mmHg; CI, 0.16-4.76) but not DBP. Continuous energy restriction (CER) significantly reduced BMI (1.11 kg/m2; CI = 0.16, 2.06) and waist circumference (3.28 cm; CI, 0.62-5.94).

CONCLUSIONS

This meta-analysis confirmed the preventive effect of CER and ADF on various cardiovascular risk factors. Additionally, CER is more likely to reduce obesity, and ADF is more likely to reduce blood pressure (BP). Based on this meta-analysis, CER is recommended to control obesity only for people who are obese and do not have elevated BP or other abnormal indicators. Additionally, ADF for early control or prevention is recommended for patients who have abnormal BP or other cardiovascular risk factors.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023455889.

Label-free Raman spectroscopy reveals tumor microenvironmental changes induced by intermittent fasting for the prevention of breast cancer in animal model

The development of tools that can provide a holistic picture of the evolution of the tumor microenvironment in response to intermittent fasting on the prevention of breast cancer is highly desirable. Here, we show, for the first time, the use of label-free Raman spectroscopy to reveal biomolecular alterations induced by intermittent fasting in the tumor microenvironment of breast cancer using a dimethyl-benzanthracene induced rat model. To quantify biomolecular alterations in the tumor microenvironment, chemometric analysis of Raman spectra obtained from untreated and treated tumors was performed using multivariate curve resolution-alternative least squares and support vector machines. Raman measurements revealed remarkable and robust differences in lipid, protein, and glycogen content prior to morphological manifestations in a dynamically changing tumor microenvironment, consistent with the proteomic changes observed by quantitative mass spectrometry. Taken together with its non-invasive nature, this research provides prospective evidence for the clinical translation of Raman spectroscopy to identify biomolecular variations in the microenvironment induced by intermittent fasting for the prevention of breast cancer, providing new perspectives on the specific molecular effects in the tumorigenesis of breast cancer.

Length of Overnight Fasting and 6-year Weight Change in the Cancer Prevention Study-3

BACKGROUND

Longer overnight fasting (ONF) is a potential strategy for weight control. Although promising, the evidence from large population-based studies is limited.

OBJECTIVES

To examine the association of self-reported ONF duration with 3- and 6-y weight change in the American Cancer Society's Cancer Prevention Study-3 prospective cohort.

METHODS

United States adult Cancer Prevention Study-3 participants completed a 24-h validated meal and snack timing and frequency grid (weekday and weekend) in 2015, from which weighted ONF hours were calculated. Participants reported body weight in 2015, 2018, and 2021. Three- and 6-y weight change (kg, and % body weight) were assessed.

RESULTS

Among 104,420 mostly female (78.5%) participants aged 52.7 ± 9.5 (standard deviation) y followed for 6 y, a 1-h increase in ONF length was associated with a small but statistically significant reduction in weight gain over 3- and 6-y periods [multivariable-adjusted mean difference in % body weight = -0.02, 95% confidence interval (CI): -0.05, -0.00, P = 0.03 and -0.04, 95% CI: -0.07, -0.01, P < 0.01, respectively]. The mean difference of 6-y % reduction in weight gain was slightly greater among individuals with overweight (-0.05, 95% CI: -0.10, 0.00, P = 0.05) and obesity (-0.06, 95% CI: -0.12, 0.01, P = 0.08) compared with those with healthy body mass index (-0.03, 95% CI:-0.07, 0.01, P = 0.13) or underweight (0.16, 95% CI: -0.04, 0.36, P = 0.13, Pinteraction < 0.0001). Stronger associations were observed among those ≤55 y than 56+ (P < 0.001), and those with higher waist circumference (Pinteraction < 0.0001) but not by sex or earlier/later fasting period.

CONCLUSIONS

Longer ONF was associated with slightly lower body weight in adult males and females over 6 y that was stronger among those with overweight or obesity, higher waist circumference, and those aged ≤55 y. The magnitude of weight change, although in the hypothesized direction, suggests that prolonged ONF may have modest impact on weight control over time.

Intermittent fasting influences immunity and metabolism

Intermittent fasting (IF) modifies cell- and tissue-specific immunometabolic responses that dictate metabolic flexibility and inflammation during obesity and type 2 diabetes (T2D). Fasting forces periods of metabolic flexibility and necessitates increased use of different substrates. IF can lower metabolic inflammation and improve glucose metabolism without lowering obesity and can influence time-dependent, compartmentalized changes in immunity. Liver, adipose tissue, skeletal muscle, and immune cells communicate to relay metabolic and immune signals during fasting. Here we review the connections between metabolic and immune cells to explain the divergent effects of IF compared with classic caloric restriction (CR) strategies. We also explore how the immunometabolism of metabolic diseases dictates certain IF outcomes, where the gut microbiota triggers changes in immunity and metabolism during fasting.

Intermittent Fasting Regulates Metabolic Homeostasis and Improves Cardiovascular Health

Obesity is a leading cause of morbidity and mortality globally. While the prevalence of obesity has been increasing, the incidence of its related complications including dyslipidemia and cardiovascular disease (CVD) has also been rising. Recent research has focused on modalities aimed at reducing obesity. Several modalities have been suggested including behavioral and dietary changes, medications, and bariatric surgery. These modalities differ in their effectiveness and invasiveness, with dietary changes gaining more interest due to their minimal risks compared to other modalities. Specifically, intermittent fasting (IF) has been gaining interest in the past decade. IF is characterized by cycles of alternating fasting and eating windows, with several different forms practiced. IF has been shown to reduce weight and alleviate obesity-related complications. Our review of clinical and experimental studies explores the effects of IF on the lipid profile, white adipose tissue (WAT) dynamics, and the gut microbiome. Notably, IF corrects dyslipidemia, reduces WAT accumulation, and decreases inflammation, which reduces CVD and obesity. This comprehensive analysis details the protective metabolic role of IF, advocating for its integration into public health practices.

Intermittent fasting and high-intensity interval training do not alter gut microbiota composition in adult women with obesity

Obesity is advancing at an accelerated pace, and yet its treatment is still an emerging field. Although studies have demonstrated the role of the microbiota in the pathogenesis of obesity, this is the first study to show the effects of intermittent fasting (IF), combined or not with exercise, and high-intensity interval training (HIIT) on the gut microbiota composition in women with obesity. Our hypothesis is that IF combined with HIIT can promote the remodeling of the composition and function of the gut microbiota. Thirty-six women with obesity, aged between 18 and 40 yr, participated in the study. They were randomly divided into three groups: 1) IF associated with HIIT group [IF + exercise group (EX), n = 15]; 2) HIIT group (EX, n = 11); and 3) IF group (IF, n = 10). Interventions took place over 8 wk, and all assessments were performed preintervention and postintervention. The HIIT circuit was performed 3 times/wk, for 25 min/session. The IF protocol was a 5:2 (2 times/wk). Multiplex analysis of inflammatory cytokines, sequencing of the 16S rRNA gene, and gas chromatography to measure fecal concentrations of short-chain fatty acids (SCFAs) were performed. This study was registered on ClinicalTrials.gov (NCT05237154). Exercise increased fecal acetate concentrations (P = 0.04), but no changes were observed in the composition and functional profile of the microbiota. The interventions did not change the composition of the microbiota, but exercise may play a modulatory role in the production of acetate. This investigation provides clinical insights into the use of IF and HIIT for women with obesity.NEW & NOTEWORTHY This is the first investigation about alternate-day fasting combined with HITT on the gut microbiota of obese women. The study contributes to the advancement of human science involving IF and HIIT, popular strategies for managing obesity. Previous evidence has explored IF in modulating the microbiota in animal models or specific populations and clinical conditions. Despite the subtle outcomes, this study has relevance and originality in the field of gut microbiota knowledge.

The effects of intermittent fasting on body composition and cardiometabolic health in adults with prediabetes or type 2 diabetes: A systematic review and meta-analysis

AIM

To perform a meta-analysis to investigate the effects of intermittent fasting (IF), as compared with either a control diet (CON) and/or calorie restriction (CR), on body composition and cardiometabolic health in individuals with prediabetes and type 2 diabetes (T2D).

METHODS

PubMed, Web of Science, and Scopus were searched from their inception to March 2024 to identify original randomized trials with parallel or crossover designs that studied the effects of IF on body composition and cardiometabolic health. Weighted mean differences (WMDs) or standardized mean differences with 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Overall, 14 studies involving 1101 adults with prediabetes or T2D were included in the meta-analysis. IF decreased body weight (WMD -4.56 kg [95% CI -6.23 to -2.83]; p = 0.001), body mass index (BMI; WMD -1.99 kg.m2 [95% CI -2.74 to -1.23]; p = 0.001), glycated haemoglobin (HbA1c; WMD -0.81% [95% CI -1.24 to -0.38]; p = 0.001), fasting glucose (WMD -0.36 mmol/L [95% CI -0.63 to -0.09]; p = 0.008), total cholesterol (WMD -0.31 mmol/L [95% CI -0.60 to -0.02]; p = 0.03) and triglycerides (WMD -0.14 mmol/L [95% CI -0.27 to -0.01]; p = 0.02), but did not significantly decrease fat mass, insulin, low-densitiy lipoprotein, high-density lipoprotein, or blood pressure as compared with CON. Furthermore, IF decreased body weight (WMD -1.14 kg [95% CI -1.69 to -0.60]; p = 0.001) and BMI (WMD -0.43 kg.m2 [95% CI -0.58 to -0.27]; p = 0.001), but did not significantly affect fat mass, lean body mass, visceral fat, insulin, HbA1c, lipid profiles or blood pressure.

CONCLUSION

Intermittent fasting is effective for weight loss and specific cardiometabolic health markers in individuals with prediabetes or T2D. Additionally, IF is associated with a reduction in body weight and BMI compared to CR, without effects on glycaemic markers, lipid profiles or blood pressure.

Dietary fats as regulators of neutrophil plasticity: an update on molecular mechanisms

PURPOSE OF REVIEW

Contemporary guidelines for the prevention of cardio-metabolic diseases focus on the control of dietary fat intake, because of their adverse metabolic effects. Moreover, fats alter innate immune defenses, by eliciting pro-inflammatory epigenetic mechanisms on the long-living hematopoietic cell progenitors which, in the bone marrow, mainly give rise to short-living neutrophils. Nevertheless, the heterogenicity of fats and the complexity of the biology of neutrophils pose challenges in the understanding on how this class of nutrients could contribute to the development of cardio-metabolic diseases via specific molecular mechanisms activating the inflammatory response.

RECENT FINDINGS

The knowledge on the biology of neutrophils is expanding and there are now different cellular networks orchestrating site-specific reprogramming of these cells to optimize the responses against pathogens. The innate immune competence of neutrophil is altered in response to high fat diet and contributes to the development of metabolic alterations, although the precise mechanisms are still poorly understood.

SUMMARY

Defining the different molecular mechanisms involved in the fat-neutrophil crosstalk will help to reconcile the sparse data about the interaction of dietary fats with neutrophils and to tailor strategies to target neutrophils in the context of cardio-metabolic diseases.

Distinct biophysiological effects of Ramadan fasting and traditional intermittent fasting on markers of body fat storage. A real-life study

BACKGROUND

Ramadan Intermittent fasting (RIF) exerts beneficial metabolic effects and improves gastrointestinal motility. However, a comparison between RIF and the traditional 16-hours intermittent fasting (16IF), a strategy for weight loss, is lacking.

METHODS

A total of 34 subjects (median age 32.5 years, range 18-63 years; median BMI 24.5 Kg m-1², range 18.6-37.6 Kg m-1²) were assigned to RIF (N = 18) or 16IF (N = 16) for 30 days. We measured variations in anthropometric measures (BMI, waist, and abdominal circumference), serum insulin, glucose, cortisol, non-esterified fatty acid (NEFA), body fat composition (bioelectrical impedance analysis), and the ultrasonographic measurements of liver steatosis (Hepatorenal index, HRI) and thickness of subcutaneous (SAT) and visceral (VAT) fats.

RESULTS

At baseline, BMI, rates of liver steatosis and distribution of normal weight, overweight, and obese subjects were comparable between the two groups. Body weight significantly decreased at the end of fasting in both RIF (-4.2 % vs baseline, P = 0.002) and 16IF (-2.1 % vs baseline, P = 0.002). Waist and abdominal circumferences significantly decreased only in RIF as well as the amount of body fat. In subjects with liver steatosis, SAT and VAT significantly decreased following RIF, but not 16h-IF, as well as the ultrasonographic HRI.

CONCLUSION

Both 16IF and RIF are able, during 1-month, to reduce body weight. However, RIF but not 16IF also generates marked beneficial effects in terms of reduced subcutaneous fat and liver steatosis. Further studies urge to verify the effects of different models of IF in weight-cycling and long-term management of obesity and related dysmetabolic conditions, such as ectopic fat over-storage.

Effect of 5:2 intermittent fasting diet versus daily calorie restriction eating on metabolic-associated fatty liver disease-a randomized controlled trial

Objective

Both 5:2 IF diet (intermittent fasting) and daily caloric restriction eating had been suggested for management of MAFLD (Metabolic-Associated Fatty Liver Disease), this study aimed to evaluate the effects of 5:2 IF diet on body weight and metabolic parameters in adults with MAFLD, in comparison to daily caloric restriction eating.

Methods

This single-center, double-blind, prospective, randomized controlled trial included 60 patients with MAFLD, who were administered either a 5:2 IF diet limited calories consumed for 2 days each week with no restrictions on the remaining 5 (Group 5:2 IF diet) or a daily calorie restriction eating (Group daily calorie restriction). Fibrotouch-B instrument assessment, ultrasound assessment of hepatic steatosis, anthropometric indices and body composition analysis, blood sample measurements were conducted during two distinct visits: initially on the day of study commencement (T1), and subsequently at the conclusion of the 12-week intervention period (T2).

Results

In comparison to daily calorie restriction eating, the 5:2 IF diet significantly decreased the proportion of hepatic steatosis ≥moderate (29.6% vs. 59.3%, p = 0.028) and the degree of hepatic fibrosis F ≥ 2 (3.7% vs. 25.9%, p = 0.05), and fewer percentage of patients were diagnosed with fatty liver via upper abdominal ultrasound in the 5:2 intermittent fasting diet group (33.3% vs. 63.0%, p = 0.029). Additionally, the CAP (controlled attenuation parameter) and LSM (liver stiffness measurements) value were significantly lower in the 5:2 IF diet group (p < 0.05). No statistically significant differences were observed between the two groups in terms of weight, BMI (body mass index), WC (waist circumference), HC (hip circumference), and WHR (waist to hip ratio). Similarly, there were no significant differences in lipid profile, glycemic indices and adverse events (p > 0.05).

Conclusion

In summary, although both 5:2 IF diet and daily caloric restriction eating achieved similar effect on body weight, liver enzymes, lipid profile and glycemic indices after 12 weeks treatment, 5:2 IF diet demonstrates better improvement in fibrosis and steatosis scores independently from weight regulation. Consequently, it is anticipated to emerge as a viable dietary modality for lifestyle intervention among patients diagnosed with MAFLD.

Clinical trial registration

https://www.crd.york.ac.uk/PROSPERO, identifier ChiCTR2400080292.

Religious Dietary Practices: Health Outcomes and Psychological Insights From Various Countries

Religious beliefs profoundly influence dietary practices across diverse cultures and communities, guiding what foods are acceptable, how they are prepared, and the timing of consumption. This narrative review examines the intricate relationship between religious dietary practices and their health and psychological well-being implications. Religious dietary practices, deeply rooted in various cultural and historical contexts, significantly influence followers' food consumption patterns. This narrative review aims to discuss how religions such as Judaism, Islam, Hinduism, and Buddhism prescribe specific dietary laws and guidelines, impacting nutritional intake and health outcomes. Furthermore, it delves into the psychological mechanisms, such as cognitive dissonance and social identity theories, that underpin adherence to these dietary practices. The review also highlights the role of community and social support in reinforcing dietary habits within religious contexts, contributing to mental health and social cohesion. By synthesizing insights from nutrition, psychology, and religious studies, this narrative review aims to provide healthcare providers with culturally sensitive dietary advice, ultimately improving patient care and promoting holistic health. Religious dietary practices provide numerous health benefits, including reduced risks of chronic diseases and enhanced mental well-being, achieved through disciplined and conscientious eating habits. Nevertheless, these practices also pose nutritional challenges that necessitate meticulous management and dietary planning.

Synchronizing food availability with the natural rhythm substantially improves reproduction and extends healthspan in laying hens

Disrupted sleep due to nighttime eating can raise various concerns, impacting both physical health and overall well-being. Nevertheless, there is a lack of direct evidence linking nighttime eating with the female reproduction system, possibly due to the absence of suitable models. Here, we use the laying hen, a diurnal animal maintained under ad libitum feeding, as a vertebrate model to quantify the impact of nighttime eating on reproduction and aging. To do this, we have built an Arduino-based setup that regulates food availability and exclusively tracks the eating events of individuals. Our data indicate that synchronizing food availability with the natural sleep-wake rhythm substantially improves reproduction and extends healthspan in hens. With reproductive aging becoming progressively more prevalent in contemporary society due to the trend of delayed childbearing, synchronizing eating with the natural rhythm could help mitigate reproductive aging in vertebrates and potentially in humans as well.

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

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

Body Mass Index, Adherence to a Healthy Lifestyle, and Breakfast Consumption Associated with Religious Affiliation in Peruvian University Students: A Cross-Sectional Study

BACKGROUND

Despite evidence suggesting a relationship between religiosity and health habits, there is a paucity of studies specifically examining this association in the context of Peruvian university students. This study compared body mass index (BMI), adherence to a healthy lifestyle, and breakfast consumption in Peruvian university students of four religious denominations: Seventh Day Adventists (SDA), Catholics, Baptists, and Evangelicals.

METHODS

A cross-sectional study was conducted online among 4557 students from a Peruvian university. The BMI and the frequency of breakfast consumption were evaluated, and the Diet and Healthy Lifestyle Scale (DEVS) was applied. The variables studied were associated using simple and multiple linear regression and Poisson models with robust variance.

RESULTS

Baptist (B = 0.44, 95% CI: 0.10-0.78; p = 0.011), Catholic (B = 0.3, 95% CI: 0.12-0.47; p = 0.001), and Evangelical (B = 0.32, 95% CI: 0.09 to 0.64; p = 0.014) students had a significantly higher BMI compared to SDA. Baptist (B = -0.2, 95% CI: -0.37--0.05; p = 0.017) and Evangelical (B = -0.13, 95% CI: -0.28--0.03; p = 0.012) students exhibited a lower mean score on the measure of healthy lifestyles compared to SDA students. Additionally, Baptist (PR = -0.32, 95% CI: -0.92--0.12; p = 0.035) and Catholic (PR = -0.3, 95% CI: -0.99--0.19; p = 0.016) students exhibited a lower probability of eating breakfast regularly compared to SDA students.

CONCLUSIONS

Health professionals should consider these findings when designing and implementing health promotion programs that are culturally sensitive and respectful of the beliefs and practices of all religious groups in university settings.

The interplay between mitochondria, the gut microbiome and metabolites and their therapeutic potential in primary mitochondrial disease

The various roles of the mitochondria and the microbiome in health and disease have been thoroughly investigated, though they are often examined independently and in the context of chronic disease. However, the mitochondria and microbiome are closely connected, namely, through their evolution, maternal inheritance patterns, overlapping role in many diseases and their importance in the maintenance of human health. The concept known as the "mitochondria-microbiome crosstalk" is the ongoing bidirectional crosstalk between these two entities and warrants further exploration and consideration, especially in the context of primary mitochondrial disease, where mitochondrial dysfunction can be detrimental for clinical manifestation of disease, and the role and composition of the microbiome is rarely investigated. A potential mechanism underlying this crosstalk is the role of metabolites from both the mitochondria and the microbiome. During digestion, gut microbes modulate compounds found in food, which can produce metabolites with various bioactive effects. Similarly, mitochondrial metabolites are produced from substrates that undergo biochemical processes during cellular respiration. This review aims to provide an overview of current literature examining the mitochondria-microbiome crosstalk, the role of commonly studied metabolites serve in signaling and mediating these biochemical pathways, and the impact diet has on both the mitochondria and the microbiome. As a final point, this review highlights the up-to-date implications of the mitochondria-microbiome crosstalk in mitochondrial disease and its potential as a therapeutic tool or target.

From fasting to fat reshaping: exploring the molecular pathways of intermittent fasting-induced adipose tissue remodeling

Obesity, characterised by excessive fat accumulation, is a complex chronic condition that results from dysfunctional adipose tissue expansion due to prolonged calorie surplus. This leads to rapid adipocyte enlargement that exceeds the support capacity of the surrounding neurovascular network, resulting in increased hypoxia, inflammation, and insulin resistance. Intermittent fasting (IF), a dietary regimen that cycles between periods of fasting and eating, has emerged as an effective strategy to combat obesity and improve metabolic homeostasis by promoting healthy adipose tissue remodeling. However, the precise molecular and cellular mechanisms behind the metabolic improvements and remodeling of white adipose tissue (WAT) driven by IF remain elusive. This review aims to summarise and discuss the relationship between IF and adipose tissue remodeling and explore the potential mechanisms through which IF induces alterations in WAT. This includes several key structural changes, including angiogenesis and sympathetic innervation of WAT. We will also discuss the involvement of key signalling pathways, such as PI3K, SIRT, mTOR, and AMPK, which potentially play a crucial role in IF-mediated metabolic adaptations.

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27-Hydroxycholesterol acts on estrogen receptor α expressed by POMC neurons in the arcuate nucleus to modulate feeding behavior

Oxysterols are metabolites of cholesterol that regulate cholesterol homeostasis. Among these, the most abundant oxysterol is 27-hydroxycholesterol (27HC), which can cross the blood-brain barrier. Because 27HC functions as an endogenous selective estrogen receptor modulator, we hypothesize that 27HC binds to the estrogen receptor α (ERα) in the brain to regulate energy balance. Supporting this view, we found that delivering 27HC to the brain reduced food intake and activated proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (POMCARH) in an ERα-dependent manner. In addition, we observed that inhibiting brain ERα, deleting ERα in POMC neurons, or chemogenetic inhibition of POMCARH neurons blocked the anorexigenic effects of 27HC. Mechanistically, we further revealed that 27HC stimulates POMCARH neurons by inhibiting the small conductance of the calcium-activated potassium (SK) channel. Together, our findings suggest that 27HC, through its interaction with ERα and modulation of the SK channel, inhibits food intake as a negative feedback mechanism against a surge in circulating cholesterol.

Effect of Early Time-Restricted Eating on Metabolic Markers and Body Composition in Individuals with Overweight or Obesity

This study aimed to evaluate the effect of early time-restricted eating (eTRE) on metabolic markers and body composition in individuals with overweight or obesity. Seventeen subjects completed a randomized, crossover, and controlled clinical trial. Twelve women and five men participated, with a mean age of 25.8 ± 10.0 years and a BMI of 32.0 ± 6.3 kg/m2. The eTRE intervention included 16 h of fasting (3:00 pm to 7:00 am) and 8 h of ad libitum eating (7:00 am to 03:00 pm) (16:8). The trial included four weeks of interventions followed by a four-week washout period. Body weight, waist and hip circumferences, and body composition measurements were taken. Additionally, a venous blood sample was collected for biochemical determinations. In a before-after analysis, eTRE induced a reduction in BW and BMI in women but this was not significant when compared to the control group. eTRE did not modify any other anthropometric measurements, fasting biochemical parameters, glycemic and insulinemic responses, blood pressure, or subjective appetite. In conclusion, eTRE did not induce beneficial effects on the glycemic and lipid metabolisms, body composition, subjective appetite, or blood pressure. These findings may be attributed to the special characteristics of the population and the short intervention period.

Cardiopulmonary and metabolic responses during a 2-day CPET in myalgic encephalomyelitis/chronic fatigue syndrome: translating reduced oxygen consumption to impairment status to treatment considerations

BACKGROUND

Post-exertional malaise (PEM), the hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), represents a constellation of abnormal responses to physical, cognitive, and/or emotional exertion including profound fatigue, cognitive dysfunction, and exertion intolerance, among numerous other maladies. Two sequential cardiopulmonary exercise tests (2-d CPET) provide objective evidence of abnormal responses to exertion in ME/CFS but validated only in studies with small sample sizes. Further, translation of results to impairment status and approaches to symptom reduction are lacking.

METHODS

Participants with ME/CFS (Canadian Criteria; n = 84) and sedentary controls (CTL; n = 71) completed two CPETs on a cycle ergometer separated by 24 h. Two-way repeated measures ANOVA compared CPET measures at rest, ventilatory/anaerobic threshold (VAT), and peak effort between phenotypes and CPETs. Intraclass correlations described stability of CPET measures across tests, and relevant objective CPET data indicated impairment status. A subset of case-control pairs (n = 55) matched for aerobic capacity, age, and sex, were also analyzed.

RESULTS

Unlike CTL, ME/CFS failed to reproduce CPET-1 measures during CPET-2 with significant declines at peak exertion in work, exercise time, V ˙ e, V ˙ O2, V ˙ CO2, V ˙ T, HR, O2pulse, DBP, and RPP. Likewise, CPET-2 declines were observed at VAT for V ˙ e/ V ˙ CO2, PetCO2, O2pulse, work, V ˙ O2 and SBP. Perception of effort (RPE) exceeded maximum effort criteria for ME/CFS and CTL on both CPETs. Results were similar in matched pairs. Intraclass correlations revealed greater stability in CPET variables across test days in CTL compared to ME/CFS owing to CPET-2 declines in ME/CFS. Lastly, CPET-2 data signaled more severe impairment status for ME/CFS compared to CPET-1.

CONCLUSIONS

Presently, this is the largest 2-d CPET study of ME/CFS to substantiate impaired recovery in ME/CFS following an exertional stressor. Abnormal post-exertional CPET responses persisted compared to CTL matched for aerobic capacity, indicating that fitness level does not predispose to exertion intolerance in ME/CFS. Moreover, contributions to exertion intolerance in ME/CFS by disrupted cardiac, pulmonary, and metabolic factors implicates autonomic nervous system dysregulation of blood flow and oxygen delivery for energy metabolism. The observable declines in post-exertional energy metabolism translate notably to a worsening of impairment status. Treatment considerations to address tangible reductions in physiological function are proffered.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, retrospectively registered, ID# NCT04026425, date of registration: 2019-07-17.

Role of Anti-Inflammatory Diet and Fecal Microbiota Transplant in Psoriatic Arthritis

PURPOSE

Psoriatic arthritis (PsA) is a chronic inflammatory condition with complex and heterogenous manifestations. Although a myriad of treatment options including biologic medications are available to alleviate symptoms and slow disease progression, there is currently no cure for this condition. There has been a recent emergence of understanding about the relationship between the gut microbiome and immune-mediated inflammatory diseases. This has generated interest in the potential role of dietary interventions, particularly anti-inflammatory diets, and fecal microbiota transplant (FMT) as novel therapeutic approaches. The purpose of this narrative review is to examine the role of an anti-inflammatory diet and FMT in turn and whether their combination may offer alternate approaches for the management of PsA.

METHODS

Our non-systematic narrative review was informed by a literature search using PubMed and Google Scholar using the terms anti-inflammatory diet, FMT, nutrition supplements, and PsA. Preclinical studies and non-English language articles were excluded when synthesizing the narrative review.

FINDINGS

Current randomized controlled trials (RCTs) and observational evidence suggest that a hypocaloric diet or Mediterranean diet can help achieve weight loss among PsA patients who are overweight or obese, which in turn reduces inflammation and improves disease activity. However, there is no strong data to support the beneficial effects of intermittent fasting, vitamin supplements, turmeric supplements, probiotics, or omega-3 fatty acid supplements in PsA. Current evidence on the use of FMT in PsA is limited as only one small RCT has been conducted which did not demonstrate efficacy for improving clinical symptoms.

IMPLICATIONS

Clinicians can consider recommending hypocaloric or Mediterranean diets as an adjunct to standard management of PsA, possibly under the guidance of a dietician. Further research is needed to explore the beneficial effects of the synergistic role of combining an anti-inflammatory diet with FMT in PsA.

Ghrelin is associated with an elevated mood after an overnight fast in depression

BACKGROUND

Major depressive disorder (MDD) comprises subtypes with distinct symptom profiles. For example, patients with melancholic and atypical MDD differ in the direction of appetite and body weight changes as well as mood reactivity. Despite reported links to altered energy metabolism, the role of circulating neuropeptides from the gut in modulating such symptoms remains largely elusive.

METHODS

We collected data from 103 participants, including 52 patients with MDD and 51 healthy control participants (HCP). After an overnight fast, we measured plasma levels of (acyl and des-acyl) ghrelin and participants reported their current metabolic and mood states using visual analog scales (VAS). Furthermore, they completed symptom-related questionnaires (i.e., STAI-T).

RESULTS

Patients with atypical versus melancholic MDD reported less negative affect (p = 0.025). Higher levels of acyl ghrelin (corrected for BMI) were associated with improved mood (p = 0.012), specifically in patients with MDD. These associations of ghrelin were not mood-item specific and exceeded correlations with trait markers of negative affectivity. In contrast to associations with mood state, higher levels of ghrelin were not associated with increased hunger per se or changes in appetite in patients with MDD.

LIMITATIONS

The study is limited by the cross-sectional design without an intervention.

CONCLUSIONS

Our results reveal potentially mood-enhancing effects of ghrelin in fasting individuals that exceed associations with metabolic state ratings. These associations with circulating neuropeptides might help explain anti-depressive effects of fasting interventions and could complement conventional treatments in patients with melancholic MDD.

Intermittent Metabolic Switching and Vascular Cognitive Impairment

Intermittent fasting (IF), a dietary pattern alternating between eating and fasting periods within a 24-hour cycle, has garnered recognition for its potential to enhance both healthspan and lifespan in animal models and humans. It also shows promise in alleviating age-related diseases, including neurodegeneration. Vascular cognitive impairment (VCI) spans a severity range from mild cognitive deficits to severe cognitive deficits and loss of function in vascular dementia. Chronic cerebral hypoperfusion has emerged as a significant contributor to VCI, instigating vascular pathologies such as microbleeds, blood-brain barrier dysfunction, neuronal loss, and white matter lesions. Preclinical studies in rodents strongly suggest that IF has the potential to attenuate pathological mechanisms, including excitotoxicity, oxidative stress, inflammation, and cell death pathways in VCI models. Hence, this supports evaluating IF in clinical trials for both existing and at-risk VCI patients. This review compiles existing data supporting IF's potential in treating VCI-related vascular and neuronal pathologies, emphasizing the mechanisms by which IF may mitigate these issues. Hence providing a comprehensive overview of the available data supporting IF's potential in treating VCI by emphasizing the underlying mechanisms that make IF a promising intervention for VCI.

Intermittent Fasting: Socio-Economic Profile of Spanish Citizens Who Practice It and the Influence of This Dietary Pattern on the Health and Lifestyle Habits of the Population

Intermittent fasting (IF) is a dietary approach that has gained popularity in recent years. More and more Spanish people are following this eating pattern, which consists of alternating periods of fasting with periods of food intake. Its benefits include improved metabolic and vascular health and weight loss.

OBJECTIVES

1. To study the prevalence of IF among the Spanish population. 2. To explore how demographic factors influence the choice to adopt this dietary approach.

METHODS

A descriptive cross-sectional study was conducted on the Spanish population using the NutSo-HH questionnaire, which was constructed, validated, and disseminated by the research team through a non-probabilistic snowball sampling approach, collecting socio-demographic data and nutritional, social and lifestyle habits of the population.

RESULTS AND CONCLUSIONS

A valid sample of 22,181 people participated, of whom 4.59% (n = 1018) said they practiced IF. The data show that more middle-aged men than women practice IF. In addition, individuals who follow IF methods are less likely to have no control over their food intake, are less scared to gain weight and have a higher body image, but no differences were found related to unhealthy food and nights out. There were also no significant differences in terms of the level of education, income, size of municipality, or region of residence. In conclusion, a person who practices IF seems to have adopted a healthier lifestyle and social habits.

A National Study Exploring the Association between Fasting Duration and Mortality among the Elderly

(1) Background: The benefits of weight management are widely recognized, and prolonged fasting duration has become a common method for weight control. The suitability of time-restricted eating (TRE) for elderly individuals remains controversial. This study aims to examine the correlation between fasting duration and mortality within a nationally representative cohort of elderly individuals in the United States. (2) Methods: Data were extracted from a prospective cohort study conducted as part of the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Participants aged over 60 with complete data on dietary intake and mortality follow-up information were included. Fasting duration was assessed using two 24 h dietary recalls. All the participants were categorized into fasting duration quartiles. Mortality outcomes were ascertained through the National Death Index. Cox proportional hazards regression models were utilized to analyze the association between fasting duration and mortality. (3) Results: The final analysis included 10,561 elderly participants (mean age 69.89, 45.58% male). Individuals with the longest fasting duration (over 12.38 h) had a significantly higher risk of CVD mortality compared to those with a normal fasting duration (10.58-12.38 h). This elevated CVD mortality risk was particularly pronounced in males, individuals over 70 years old, and non-shift workers. A non-linear relationship was observed between fasting duration and all-cause mortality and CVD mortality. (4) Conclusions: Prolonged fasting periods are associated with a higher risk of CVD mortality in the elderly population, although this correlation is not evident for all-cause, cancer, or other-cause mortality. A fasting duration of 11.49 h correlates with the lowest mortality risk. Additionally, elderly individuals with the shortest fasting duration exhibit elevated hazard ratios for both cancer and other-cause mortality. As with any health intervention, clinicians should exercise caution when recommending a fasting regimen that is personalized to the health condition of people who are older. Further research through randomized controlled trials should be conducted to comprehensively investigate the impact of TRE on mortality.

A detective story of intermittent fasting effect on immunity

Intermittent fasting (IF) refers to periodic fasting routines, that caloric intake is minimized not by meal portion size reduction but by intermittently eliminating ingestion of one or several consecutive meals. IF can instigate comprehensive and multifaceted alterations in energy metabolism, these metabolic channels may aboundingly function as primordial mechanisms that interface with the immune system, instigating intricate immune transformations. This review delivers a comprehensive understanding of IF, paying particular attention to its influence on the immune system, thus seeking to bridge these two research domains. We explore how IF effects lipid metabolism, hormonal levels, circadian rhythm, autophagy, oxidative stress, gut microbiota, and intestinal barrier integrity, and conjecture about the mechanisms orchestrating the intersect between these factors and the immune system. Moreover, the review includes research findings on the implications of IF on the immune system and patients burdened with autoimmune diseases.

Intermittent fasting and cardiovascular disease: A scoping review of the evidence

Intermittent fasting (IF), characterized by alternating periods of fasting and unrestricted eating, typically within an 8-hour window or less each day, has gained significant attention as a possible dietary approach. While it is recognized for its metabolic advantages, like weight loss and enhanced glucose and insulin sensitivity, its effect on cardiovascular health remains a topic of mixed opinions. Recent findings suggest a potential downside, with reports indicating a concerning association: a 91 % higher risk of cardiovascular disease (CVD) mortality compared to eating spread across a 12- to 16-hour period. Despite this alarming statistic, the evidence cannot establish a causal link. The impact of IF on CVD is still insufficiently understood, with benefits sometimes exaggerated and risks downplayed in popular discourse. This scoping review aims to consolidate the current evidence, addressing unresolved questions about the benefits and risks of IF, particularly its association with CVD risks and mortality. The goal is to provide a balanced perspective on the potential health implications of IF, emphasizing the need for further research to clarify its long-term effects on cardiovascular health.

Effects of DASH diet with or without time-restricted eating in the management of stage 1 primary hypertension: a randomized controlled trial

BACKGROUND

Time-restricted eating (TRE), a popular form of intermittent fasting, has shown benefits for improving metabolic diseases and cardiometabolic health. However, the effect of TRE in the regulation of blood pressure in primary hypertension remains unclear.

METHODS

A 6-week randomized controlled trial was conducted, in which a total of 74 stage 1 primary hypertensive patients without high-risk were randomly assigned to Dietary Approaches to Stop Hypertension (DASH) group (n = 37) or DASH + TRE group (n = 37). Participants in the DASH + TRE group were instructed to consume their food within an 8-h window. Scientific research platform in We Chat application was used to track participants. The primary outcome was blood pressure. The secondary outcomes included body composition, cardiometabolic risk factors, inflammation-related parameters, urinary Na+ excretion, other clinical variables and safety outcomes.

RESULTS

The reduction of systolic blood pressure and diastolic blood pressure were 5.595 ± 4.072 and 5.351 ± 5.643 mm Hg in the DASH group and 8.459 ± 4.260 and 9.459 ± 4.375 mm Hg in the DASH + TRE group. DASH + TRE group improved blood pressure diurnal rhythm. Subjects in DASH + TRE group had decreased extracellular water and increased urinary Na+ excretion. Furthermore, the decrease in blood pressure was associated with a reduction of extracellular water or increase in urinary Na+ excretion. In addition, safety outcomes such as nighttime hunger were also reported.

CONCLUSION

Our study demonstrated that 8-h TRE + DASH diet caused a greater decrease in blood pressure in stage 1 primary hypertensive patients than DASH diet. This study may provide novel insights into the benefits of lifestyle modification in the treatment of primary hypertension.

TRIAL REGISTRATION

https://www.chictr.org.cn/ (ChiCTR2300069393, registered on March 15, 2023).

Effects of intermittent fasting combined with exercise on serum leptin and adiponectin in adults with or without obesity: a systematic review and meta-analysis of randomized clinical trials

Context

Intermittent fasting (IF) and exercise training (Exe) have been evaluated in several studies for improving cardiometabolic biomarkers related to weight loss. However, further investigation is required to understand the potential effects on leptin and adiponectin concentrations. IF protocols have been shown to be efficient in improving adipokines, but further research is required to determine whether or not IF regimens combined with Exe are superior to Exe alone.

Objective

The aim of this study was to determine whether or not interventions combining IF plus Exe are more effective than Exe only for improving serum leptin and adiponectin in adults with and without obesity.

Data extraction

A systematic review and meta-analysis was performed by searching PubMed, Scopus, and Web of Science databases up to August 2023 for randomized clinical trials that determined the effects of IF plus Exe vs. Exe alone (control) on body weight, serum leptin, and serum adiponectin. Analyses were conducted for IF plus Exe vs. Exe alone to calculate weighted mean differences (WMD) and standardized mean differences (SMD).

Analysis

The current meta-analysis included 6 studies with a total sample of 153 participants, with intervention durations ranging from three days to 52 weeks. IF plus Exe elicited significantly larger decreases in leptin levels [SMD = -0.47, p = 0.03], which were accompanied by weight loss [WMD = -1.25 kg, p = 0.05], as compared with exercise-only interventions, but adiponectin did not differ between the two [SMD = 0.02, p = 0.9].

Conclusion

IF combined with Exe reduced leptin significantly, but did not change adiponectin levels, when compared to exercise only. Perhaps these reductions in leptin levels may have been associated with weight loss; however, due to the small number of included studies and the high heterogeneity in the weight loss outcomes, this result is uncertain.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023460735.

The regulatory effect of intermittent fasting on inflammasome activation in health and disease

Intermittent fasting (IF), one of the most popular diets, can regulate inflammation and promote health; however, the detailed molecular mechanisms are not fully understood. The present review aims to provide an overview of recent preclinical and clinical studies that have examined the effect of IF on inflammasome signaling, and to discuss the translational gap between preclinical and clinical studies. Three databases (PubMed, Web of Science, and Embase) were searched to identify all relevant preclinical and clinical studies up to October 30, 2022. A total of 1544 studies were identified through the database searches, and 29 preclinical and 10 clinical studies were included. Twenty-three of the 29 preclinical studies reported that IF treatment could reduce inflammasome activation in neurological diseases, metabolic and cardiovascular diseases, immune and inflammatory diseases, gastrointestinal diseases, and pulmonary diseases, and 7 of the 10 clinical studies demonstrated reduced inflammasome activation after IF intervention in both healthy and obese participants. Among various IF regimens, time-restricted eating seemed to be the most effective one in terms of inflammasome regulation, and the efficacy of IF might increase over time. This review highlights the regulatory effect of IF on inflammasome activation in health and disease. Future studies using different IF regimens, in various populations, are needed in order to evaluate its potential to be used alone or as an adjunct therapy in humans to improve health and counteract diseases.

Impact of whole grain highland hull-less barley on the denaturing gradient gel electrophoresis profiles of gut microbial communities in rats fed high-fat diets

Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) is a traditional non-culture technique that can provide a fingerprint of the microbial community. In the field of gut microbiota analysis, PCR-DGGE still holds potential for development. In the present study, we utilized an improved nested PCR-DGGE approach targeting the V3 region of 16S ribosomal DNA to investigate the impact of whole grain highland hull-less barley (WHLB), a cereal known for its significant hypocholesterolemic effect, on the gut microbiota profiles of high-fat diet rats. Seventy-two male Sprague-Dawley rats were divided into four groups and fed a normal control diet, a high-fat diet, or a high-fat diet supplemented with a low or high dose of WHLB for 4 or 8 weeks. The results revealed that the dominant bands varied among different dose groups and further changed with different treatment times. The compositions of bacterial communities in feces and cecal content were similar, but the dominant bacterial bands differed. After performing double DGGE, extracting the bands, sequencing the DNA, and aligning the sequences, a total of 19 bands were classified under the Firmicutes and Bacteroidetes phyla, while two bands were identified as unclassified uncultured bacteria. The relative abundance of Lactobacillus gasseri, Uncultured Prevotella sp., and Clostridium sp. increased following the administration of WHLB. Illumina-based sequencing was employed to assess the reliability of DGGE, demonstrating its reliability in analyzing the dominant taxonomic composition, although it may have limitations in accurately detecting the alpha diversity of bacterial species.

IMPORTANCE

While next-generation sequencing has overshadowed polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), the latter still holds promise for advancing gut microbiota analysis due to its unique advantages. In this study, we used optimized nested PCR-DGGE to investigate the gut microbiota profile of high-fat diet rats after administering whole grain highland hull-less barley. High-throughput sequencing was employed to validate the DGGE results. Our results proved the reliability of PCR-DGGE for analyzing the dominant taxonomic composition while also providing visual evidence of a notable relationship between the composition of cecal and fecal microbial communities, highlighting substantial differences in both richness and abundance.

Breakfast skipping and risk of all-cause, cardiovascular and cancer mortality among adults: a systematic review and meta-analysis of prospective cohort studies

Background: Numerous studies reported inconsistent association between breakfast skipping and all-cause, cardiovascular disease (CVD) and cancer mortality. Therefore, we conducted a systematic review and meta-analysis to elucidate these associations. Methods: PubMed, Embase, and Web of Science databases were searched up to July 2023 for prospective cohort studies that assessed the association between breakfast skipping and all-cause, CVD and cancer mortality in general adults. A random effect model was used to estimate the pooled hazard ratio (HR) and 95% confidence intervals (CIs), with subgroup analysis and sensitivity analysis performed. The Newcastle-Ottawa Scale (NOS) was used to assess the study and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool was used to assess the risk of bias. Results: The final analysis included 9 cohort studies including 242 095 participants, with 6 studies for all-cause mortality, 4 studies for CVD mortality, and 2 studies for cancer mortality. Compared to regular breakfast consumption, skipping breakfast was associated with a higher risk of all-cause (HR: 1.27, 95% CI, 1.07-1.51, I2 = 77%), CVD (HR 1.28, 95% CI 1.10-1.50, I2 = 0), and cancer (HR: 1.34, 95% CI: 1.11-1.61, I2 = 0%) mortality. Sensitivity analysis revealed inconsistent results in all-cause and CVD mortality. Subgroup analysis showed significant association in studies with larger participants, longer follow-up, adjustments for energy intake, and high-quality articles. GRADE showed very low evidence for all-cause mortality and low evidence for CVD and cancer mortality. Conclusion: The findings underscore the importance of regular breakfast habits for health and longevity. However, these results require careful interpretation due to geographic limitations, potential heterogeneity, and instability.

Effects of Calorie Restriction on Preserving Male Fertility Particularly in a State of Obesity

PURPOSE OF REVIEW

Highlight the importance of exploring nutritional interventions that could be applied as alternative or supplementary therapeutic strategies to enhance men's fertility.

RECENT FINDINGS

Lifestyle choices have prompted extensive discussions regarding its implications and applications as a complementary therapy. The growing concern over the decline in sperm quality underscores the urgency of investigating these alternative interventions. Calorie restriction (CR) has emerged as a promising strategy to improve male fertility. The efficacy of CR depends on factors like age, ethnicity and genetics. Clinical studies, such as CALERIE, have shown an improvement in serum testosterone level and sexual drive in men with or without obesity. Additionally, CR has been shown to positively impact sperm count and motility; however, its effects on sperm morphology and DNA fragmentation remain less clear, and the literature has shown discrepancies, mainly due to the nature of technically dependent assessment tools. The review advocates a personalized approach to CR, considering individual health profiles to maximize its benefits. It underscores the need for routine, accessible diagnostic techniques in male reproductive health. It suggests that future research should focus on personalized dietary interventions to improve male fertility and overall well-being in individuals with or without obesity and unravel CR's immediate and lasting effects on semen parameters in men without obesity.

Associations of meal timing and sleep duration with incidence of obesity: a prospective cohort study

OBJECTIVES

Late mealtime and short sleep are known to be associated with obesity risk due to a misaligned circadian rhythm. This study aimed to investigate the relationship between obesity and mealtime and sleep duration using the Korean Genome and Epidemiology Study (KoGES) data.

DESIGN

Longitudinally prospective cohort study.

SETTING

Population-based.

PARTICIPANTS

KoGES analysed data from 9,474 Korean adults with an average age of 54- years old at baseline.

MEASUREMENTS

Meal timing was defined as the eating occasions of the day reported by the participant eating a 24-h dietary recall method. Sleep duration was categorized as <6, 6-7, 7-8, and ≥8 h. The Cox proportional hazard model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident obesity according to meal timing, sleep duration, and nightly fasting duration.

RESULTS

During a mean follow-up of 3.5 years, 826 participants developed obesity. In the multivariable-adjusted analysis, midnight snack eating (HR, 1.20; 95% CI, 1.02-1.41) and higher energy intake from midnight snacks (HR, 1.26; 95% CI, 1.06-1.49) were associated with a higher risk of obesity. Sleeping 8 h or more (HR, 0.67; 95% CI, 0.53-0.85) was associated with a lower risk of obesity.

CONCLUSIONS

Our findings highlight the importance of meal and sleep times and suggest that healthy eating habits related to the time of day.

Scoping review: Exploring the relationship between chrononutrition and glycemic responses in the adult population

Chrononutrition, an emerging body of evidence on the relationship between biological rhythms and metabolism, has been established to be associated with glycemic responses. However, the available evidence is inconsistent, due to protocol variations. Therefore, this review aims to summarize the findings on chrononutrition characteristics and their association with glycemic responses among adults. Systematic searches were conducted across six databases (PubMed, EBSCO Host, ProQuest Central, MEDLINE & Ovid, Scopus and Web of Science) to identify all relevant studies published from January 2012. Two reviewers independently screened the abstracts and full-text articles based on the inclusion and exclusion criteria. Details about population characteristics, study methods and key findings were extracted following the PRISMA-ScR guideline. The quality of selected studies was evaluated using the mixed methods appraisal tool. The searchers identified 49 studies eligible for analysis. The results showed that meal timing, particularly night-time eating and snacking were associated with glycemic responses. Regarding meal regularity, skipping breakfast may affect glycemic responses, but no clear conclusion was drawn about its effect on insulin. The association between meal frequency and glycemic responses was inconclusive. Night fasting duration and restricted eating window are potentially associated with glycemic responses. The current review extensively investigates the association between chrononutrition factors and glycemic responses in adults. However, more prospective cohort and interventional studies are needed to better understand this causal-effect relationship.

Impact of Ramadan fasting on serum levels of major endocrinology hormonal and biochemical parameters in healthy non-athlete adults: A systematic review and meta-analyses

BACKGROUND

Ramadan Intermittent Fasting (RIF) has the potential to alter hormonal levels in the body. This study investigates the impact of RIF on hormonal levels among healthy individuals during Ramadan.

METHODS

A systematic review and meta-analysis of previously published studies were conducted, focusing on healthy non-athlete adults. The intervention examined was Ramadan Intermittent Fasting, and the primary outcomes assessed were changes in endocrine hormonal and biochemical parameters. The pooled effect measure was expressed as odds ratio (OR) and 95% confidence interval (CI) using the random-effects model.

RESULTS

A total of 35 original articles were retrieved, with a combined sample size of 1,107 participants eligible for the meta-analysis. No significant relationship was found between pre- and post-Ramadan hormonal levels of T3, T4, TSH, FT3, FT4, Testosterone, LH, FSH, Prolactin, PTH, Calcium, and Phosphorus (P-value<0.05). However, a substantial decrease in morning cortisol levels was observed across the studies (P-value: 0.08, Hedges' g = -2.14, 95% CI: -4.54, 0.27).

CONCLUSIONS

Ramadan Intermittent Fasting results in minimal hormonal changes and is a safe practice for healthy individuals. The fasting regimen appears to disrupt the circadian rhythm, leading to a decrease in morning cortisol levels.

Treatment of mice with maternal intermittent fasting to improve the fertilization rate and reproduction

Maternal intermittent fasting (MIF) can have significant effects on several tissue and organ systems of the body, but there is a lack of research on the effects on the reproductive system. So, the aim of our study was to analyze the effects of MIF on fertility. B6C3F1Crl (C57BL/6N × C3H/HeN) male and female mice were selected for the first part of the experiments and were analyzed for body weight and fat weight after administration of the MIF intervention, followed by analysis of sperm counts and activation and embryo numbers. Subsequently, two strains of mice, C57BL/6NCrl and BALB/cJRj, were selected and administered MIF to observe the presence or absence of vaginal plugs for the purposes of mating success, sperm and oocyte quality, pregnancy outcome, fertility status and in vitro fertilization (IVF). Our results showed a significant reduction in body weight and fat content in mice receiving MIF intervention in B6C3F1Crl mice. Comparing the reproduction of the two strains of mice. However, the number of litters was increased in all MIF interventions in C57BL/6NCrl, but not statistically significant. In BALB/cJRj, there was a significant increase in the number of pregnant females as well as litter size in the MIF treatment group, as well as vaginal plugs, and IVF. There was also an increase in sperm activation and embryo number and the MIF intervention significantly increased sperm count and activation. Our results suggest that MIF interventions may be beneficial for reproduction in mice.

Biological Rhythms, Chrono-Nutrition, and Gut Microbiota: Epigenomics Insights for Precision Nutrition and Metabolic Health

Circadian rhythms integrate a finely tuned network of biological processes recurring every 24 h, intricately coordinating the machinery of all cells. This self-regulating system plays a pivotal role in synchronizing physiological and behavioral responses, ensuring an adaptive metabolism within the environmental milieu, including dietary and physical activity habits. The systemic integration of circadian homeostasis involves a balance of biological rhythms, each synchronically linked to the central circadian clock. Central to this orchestration is the temporal dimension of nutrient and food intake, an aspect closely interwoven with the neuroendocrine circuit, gut physiology, and resident microbiota. Indeed, the timing of meals exerts a profound influence on cell cycle regulation through genomic and epigenetic processes, particularly those involving gene expression, DNA methylation and repair, and non-coding RNA activity. These (epi)genomic interactions involve a dynamic interface between circadian rhythms, nutrition, and the gut microbiota, shaping the metabolic and immune landscape of the host. This research endeavors to illustrate the intricate (epi)genetic interplay that modulates the synchronization of circadian rhythms, nutritional signaling, and the gut microbiota, unravelling the repercussions on metabolic health while suggesting the potential benefits of feed circadian realignment as a non-invasive therapeutic strategy for systemic metabolic modulation via gut microbiota. This exploration delves into the interconnections that underscore the significance of temporal eating patterns, offering insights regarding circadian rhythms, gut microbiota, and chrono-nutrition interactions with (epi)genomic phenomena, thereby influencing diverse aspects of metabolic, well-being, and quality of life outcomes.

Clinical potential of fasting in type 1 diabetes

Most adults with type 1 diabetes (T1DM) are either overweight or obese. As such, dietary management is recommended as an adjunct to insulin treatment to improve glycemic control and facilitate weight loss in these patients. Time-restricted eating (TRE) is a form of intermittent fasting that offers a simplified approach to treating obesity in T1DM. TRE typically involves restricting eating to 6 to 10 h per day, with water and medications allowed outside the eating window. This review examines the efficacy of TRE and other fasting protocols in improving weight and glycemic control in patients with obesity and T1DM. This review will also evaluate the safety of these regimens and provide advice to clinicians on implementing intermittent fasting in T1DM.

Intermittent fasting improves the oocyte quality of obese mice through the regulation of maternal mRNA storage and translation by LSM14B

Obesity has significant repercussions for female reproductive health, including adverse effects on oocyte quality, fertility, embryo development and offspring health. Here, we showed that intermittent fasting (IF) has several notable effects on follicular development, oocyte development and maturation and offspring health in obese mice. IF treatment prevents obesity-associated germline-soma communication defects, mitochondrial dysfunction, oxidative damage, apoptosis, and spindle/chromosomal disruption. RNA-sequencing analysis of oocytes from normal diet (ND), high-fat diet (HFD), and HFD + IF mice indicated that IF treatment improved mitochondrial oxidative phosphorylation function and mRNA storage and translation, which was potentially mediated by the Smith-like family member 14 B (LSM14B). Knockdown of LSM14B by siRNA injection in oocytes from ND mice recapitulates all the translation, mitochondrial dysfunction and meiotic defect phenotypes of oocytes from HFD mice. Remarkably, the injection of Lsm14b mRNA into oocytes from HFD mice rescued the translation, mitochondrial dysfunction and meiotic defect phenotypes. These results demonstrated that dysfunction in the oocyte translation program is associated with obesity-induced meiotic defects, while IF treatment increased LSM14B expression and maternal mRNA translation and restored oocyte quality. This research has important implications for understanding the effects of obesity on female reproductive health and offers a potential nonpharmacological intervention to improve oocyte quality and fertility in obese individuals.

Intermittent fasting associated with coconut oil (Cocos nucifera L.) alters gut-liver axis parameters in diet-induced obese rats

OBJECTIVE

The aim of this article is to investigate the effect of intermittent fasting, associated or not with coconut oil intake, on the gut-liver axis of obese rats.

METHODS

A total of 50 rats were divided into five groups: control, obese, obese with intermittent fasting, obese with intermittent fasting plus coconut oil, and obese with caloric restriction. The rats were induced to obesity with a high-sugar diet for 17 wk. The respective interventions were carried out in the last 4 wk.

RESULTS

The groups with intermittent fasting protocols had reduced total cholesterol (on average 54.31%), low-density lipoprotein (on average 53.39%), and triacylglycerols (on average 23.94%) versus the obese group; and the obese with intermittent fasting plus coconut oil group had the highest high-density lipoprotein compared with all groups. The obese with intermittent fasting plus coconut oil and obese with caloric restriction groups had lower metabolic load compared with the other groups. The obese group had high citric and succinic acid concentrations, which affected the hepatic tricarboxylic acid cycle, while all the interventions had reduced concentrations of these acids. No histologic changes were observed in the intestine or liver of the groups.

CONCLUSION

Intermittent fasting, especially when associated with coconut oil, had effects comparable with caloric restriction in modulating the parameters of the gut-liver axis.

Intermittent fasting modulates human gut microbiota diversity in a phenotype-dependent manner: a systematic review

Cumulative evidence suggests that intermittent fasting (IF) has beneficial effects on human metabolic health. It has been indicated that its impact on the gut microbiota may mediate these beneficial effects. As a result, we hypothesized that IF may impact the human gut microbiota. A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol using the PubMed, Scopus, and CINAHL databases. We registered our systematic review protocol in PROSPERO under registration number CRD42021270050. Human intervention studies published until April 30, 2023, were included. The quality of the included studies was assessed using National Institutes of Health (NIH) quality assessment study tools for intervention studies. The search in the database returned 166 studies, of which 13 matched all criteria for the final qualitative analysis. The body of evidence suggests that IF modulates human gut microbiota alpha and beta diversity in lean (relatively healthy) and relatively healthy overweight/obese individuals but not in individuals with metabolic syndrome. Furthermore, IF also alters human gut microbiota composition in all phenotypes. Of interest, the gut microbiota taxa or microbial metabolites after an IF intervention are associated with metabolic markers. According to this review, IF influences the diversity and taxonomic levels of the human gut microbiota. Individual metabolic phenotypes may alter the effect of IF on the diversity and taxonomic levels of the gut microbiota.

Metabolic Syndrome According to Dietary and Health-Related Lifestyle in Male Cancer Survivors and Non-Cancer over 40 Years of Age

Researchers often report higher metabolic syndrome (MetS) pr\4;evalence among cancer survivors than among non-cancer individuals. This study aims to explore the impact of cancer presence, activity type, and dietary lifestyle on MetS in males over 40 years of age. Participants (n = 9846; 618 cancer survivors, 9228 non-cancer) were selected by extracting data from a Korean government database spanning the years 2016 to 2021. Physical activity patterns, dietary habits, and MetS factors were measured, and a multiple logistic regression analysis was statistically processed for an odds ratio (OR). MetS was present in 32.8% of cancer survivors and 28.6% of non-cancer individuals. Gastric cancer survivors exhibited a 16% lower OR for MetS versus non-cancer participants. The ORs were higher by 1.60-, 1.45-, and 1.26-fold for colorectal, urinary, and other cancers, respectively. Cancer survivors with high calorie, carbohydrate, and fat intakes exhibited ORs of 2.01 (95% CI 1.28-4.04), 2.33 (95% CI 1.28-4.54), and 1.39 (95% CI 1.05-2.37) compared to the recommended level. The high fiber-intake group reduced the MetS OR by 20%. In conclusion, The MetS prevalence was higher in survivors with colorectal cancer, urinary cancer, and other cancers, while it was lower in patients with gastric cancer. Survivors with low rates of eating three meals a day, high skipping breakfast, increased eating-out rate, and no nutritional learning opportunity displayed higher MetS prevalence. Additionally, cancer survivors who had more strength and leisure activities had a lower OR of MetS.

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.

Intermittent fasting and longevity: From animal models to implication for humans

In recent years, intermittent fasting (IF) and its numerous modifications have been increasingly suggested as a promising therapy for age-related problems and a non-pharmacological strategy to extend lifespan. Despite the great variability in feeding schedules that we describe in the current work, underlying physiological processes are the same and include a periodic switch from glucose metabolism (generated by glycogenolysis) to fatty acids and fatty acid-derived ketones. Many of the beneficial effects of IF appear to be mediated by optimization of energy utilization. Findings to date from both human and animal experiments indicate that fasting improves physiological function, enhances performance, and slows aging and disease processes. In this review, we discuss some of the remarkable discoveries about the beneficial effects of IF on metabolism, endocrine and cardiovascular systems, cancer prevention, brain health, neurodegeneration and aging. Experimental studies on rodent models and human investigations are summarized to compare the outcomes and underlying mechanisms of IF. Metabolic and cellular responses triggered by IF could help to achieve the aim of preventing disease, and maximizing healthspan and longevity with minimal side effects.

Investigation of the effect of Ramadan fasting on serum levels of melatonin, cortisol, and serotonin: the case of Turkey

INTRODUCTION

The aim of this study is to examine the effects of Ramadan fasting on melatonin, cortisol, and serotonin levels.

METHODS

In this study, the blood of 19 healthy male individuals between the ages of 26 and 51, registered in Agri (Turkey) Family Health Center and fasting during Ramadan, was studied. The study was carried out in 2021-2022. The SPSS-22 package program was used in the analysis of the data. Wilcoxon analysis was used in the study.

RESULTS

It was determined that the pre-test-post-test melatonin and cortisol levels of the individuals were not statistically significant (p>0.05). It was determined that the pre-test-post-test serotonin difference of the individuals was statistically significant (p<0.05).

CONCLUSION

It has been determined that Ramadan fasting increases the serotonin level of individuals but does not change the levels of melatonin and cortisol. It was determined that the level of happiness of individuals increased after Ramadan fasting. Longitudinal studies on the effects of Ramadan fasting are recommended.