Meal frequency and timing in health and disease

Cardiometabolic and obesity risk outcomes of dawn-to-dusk, dry intermittent fasting: Insights from an umbrella review

BACKGROUND & AIMS

This umbrella review comprehensively and systematically summarizes meta-analyses on the impact of dawn-to-dusk, dry intermittent fasting of Ramadan (RIF) on cardiometabolic and glucose homeostasis indicators.

METHODS

Twenty meta-analyses were examined on the effects of RIF on body fat percentage (BFP), fat mass, fat-free mass, body mass index (BMI), body weight (BW), waist circumference (WC), systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), and very low-density lipoprotein cholesterol (VLDL-C), fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin resistance (HOMA-IR), serum insulin, leptin, and adiponectin. Results of continuous outcomes were pooled from included meta-analyses. We employed random-effects meta-analysis using the restricted maximum likelihood method to estimate heterogeneity. P-values were derived from standard meta-analytic tests, including Egger's test for small-study effects and the excess significance test for potential publication bias. Additionally, we applied criteria from Ioannidis' evidence classification to assess the credibility of the findings.

RESULTS

In healthy subjects, RIF was associated with significant reductions in BW (Hedges' G = -0.33; 95 % confidence interval (CI) = -0.37, -0.29; p-value = 2.63 × 10-52), WC (Hedges' G = -0.30; 95 % CI = -0.38, -0.23; p-value = 5.73 × 10-15), BFP (Hedges' G = -0.26; 95 % CI = -0.37, -0.14; p-value = 6.81 × 10-06), DBP (n = 3,456; Hedges' G = -0.26; 95 % CI = -0.38, -0.15; p-value = 9.18 × 10-06), TC (n = 9,314; Hedges' G = -0.16; 95 % CI = -0.25, -0.07; p-value = 6.27 × 10-04), and TG levels (n = 9,020; Hedges' G = -0.16; 95 % CI = -0.24, -0.08; p-value = 6.87 × 10-05). Moreover, in general population, TG (n = 16,688; Hedges' G = -0.15; 95 % CI = -0.22, -0.08; p-value <0.01) and FBG (n = 16,106; Hedges' G = -0.23; 95 % CI = -0.33, -0.13; p-value <0.01) were significantly reduced.

CONCLUSIONS

Dawn-to-dusk, dry RIF shows promise as a complementary therapy and preventive measure for reducing cardiometabolic and obesity-related risks. However, controlled studies are necessary to validate its effectiveness and fully understand its health implications.

Prolonged fasting promotes systemic inflammation and platelet activation in humans: A medically supervised, water-only fasting and refeeding study

OBJECTIVE

Prolonged fasting (PF), defined as abstaining from energy intake for ≥4 consecutive days, has gained interest as a potential health intervention. However, the biological effects of PF on the plasma proteome are not well understood.

METHODS

In this study, we investigated the effects of a medically supervised water-only fast (mean duration: 9.8 ± 3.1 days), followed by 5.3 ± 2.4 days of guided refeeding, in 20 middle-aged volunteers (mean age: 52.2 ± 11.8 years; BMI: 28.8 ± 6.4 kg/m2).

RESULTS

Fasting resulted in a 7.7% mean weight loss and significant increases in serum beta-hydroxybutyrate (BHB), confirming adherence. Untargeted high-dimensional plasma proteomics (SOMAScan, 1,317 proteins) revealed multiple adaptations to PF, including preservation of skeletal muscle and bone, enhanced lysosomal biogenesis, increased lipid metabolism via PPARα signaling, and reduced amyloid fiber formation. Notably, PF significantly reduced circulating amyloid beta proteins Aβ40 and Aβ42, key components of brain amyloid plaques. In addition, PF induced an acute inflammatory response, characterized by elevated plasma C-reactive protein (CRP), hepcidin, midkine, and interleukin 8 (IL-8), among others. A retrospective cohort analysis of 1,422 individuals undergoing modified fasting confirmed increased CRP levels (from 2.8 ± 0.1 to 4.3 ± 0.2 mg/L). The acute phase response, associated with transforming growth factor (TGF)-β signaling, was accompanied by increased platelet degranulation and upregulation of the complement and coagulation cascade, validated by ELISAs in blood and urine.

CONCLUSIONS

While the acute inflammatory response during PF may serve as a transient adaptive mechanism, it raises concerns regarding potential cardiometabolic effects that could persist after refeeding. Further investigation is warranted to elucidate the long-term molecular and clinical implications of PF across diverse populations.

Healthy ageing in older adults with cardiovascular disease

As life expectancy continues to increase due to advancements in medical technology, public health, nutrition, and socioeconomic progress, the population of older adults in the USA and Europe is rapidly growing. By 2050, individuals aged 65 and older are projected to constitute over 20% of the US population and 29% of the European population, leading to a higher prevalence of chronic diseases, including cardiovascular disease. Cardiovascular disease, the leading cause of death in the USA, poses significant challenges to healthy ageing by contributing to accelerated biological ageing and the development of geriatric syndromes. This state-of-the-art review aims to (i) define healthy ageing for older patients living with cardiovascular disease; (ii) compare chronological vs biological ageing as it pertains to cardiovascular disease; (iii) describe the impact of geriatric syndromes and provide an approach to management and prevention; and (iv) address the gaps in knowledge and future directions for potential interventions that could promote healthy ageing.

How Screen Time Affects Greek Schoolchildren's Eating Habits and Functional Food Consumption?-A Cross-Sectional Study

BACKGROUND

Television (TV), video games, PC and devices such as tablets and smart phones have become part of everyday life at an ever-younger age. Increased screen time correlates with unhealthy eating habits among children.

METHODS

374 children aged 9-12 years and their parents (n = 159), from 3 schools in Lemnos and 5 schools in Thessaloniki, Greece, took part in this cross-sectional study. The children completed the KIDMED score and a questionnaire about their physical activity, time spent watching TV, PC and playing electronic games, the frequency of cooking or shopping with their parents, the frequency of eating fast food, soft drinks and Functional Foods (FFs). Statistical analysis was performed with SPSS-29.0, using One Way ANOVA and Pearson chi-square.

RESULTS

As the hours of TV viewing increased, so did the percentage of children who consumed soft drinks (p = 0.03). A statistically significant association detected between television (p = 0.024), video games (p = 0.028), all screen categories (p = 0.011) and fast-food consumption. Increased screen time is associated with a higher weekly consumption of fast food (p = 0.011). The more hours children spent in front of screens, the less adherence they had to the Mediterranean Diet (p = 0.001) and less natural FFs consumption (p = 0.001).

CONCLUSIONS

The results suggest that screen time seems to affect children's eating behaviors. The study concluded that the longer the screen time, the unhealthier the dietary habits of schoolchildren become. Future research should focus on reducing screen time, as a means of improving dietary patterns and potentially reducing childhood obesity.

Caloric restriction mimetics: Pinostilbene versus resveratrol regarding SIRT1 and SIRT6 interaction

PURPOSE

Caloric restriction (CR), the permanent or periodic reduction of caloric intake, is a dietary strategy that promotes longevity and healthspan, yielding multiple beneficial effects, such as improved insulin sensitivity and mitochondrial function, decreased body weight, and mitigation of cardiometabolic risk factors. The purpose of our study was the in silico and in vitro assessment of the effects exerted by pinostilbene on SIRT1 and SIRT6 compared to those of resveratrol, a known activator of these enzymes.

MATERIALS AND METHODS

Molecular docking was carried out to determine the interactions with SIRT1 and SIRT6 and, further, the effect of pinostilbene on their activity was tested in vitro to evaluate if it parallels resveratrol's effects regarding SIRT activation.

RESULTS

Molecular docking indicates that resveratrol and pinostilbene bind similarly to SIRT6, while pinostilbene may be able to activate SIRT1 more efficiently than resveratrol. In vitro activity assays showed that while both resveratrol and pinostilbene activate SIRT1 and SIRT6, the concentration-dependent effects differ. For resveratrol, a greater effect was observed at the medium concentration (25 ​μM), whereas pinostilbene showed a more pronounced activation at the lowest concentration (5 ​μM).

CONCLUSIONS

Our results offer a glimpse into the structural features and interactions of pinostilbene and resveratrol with SIRT1 and SIRT6, contributing to understanding their potential roles in various cellular processes regulated by SIRT.

Intermittent Fasting: Implications for Obesity-Related Colorectal Tumorigenesis

Obesity is associated with metabolic and immune perturbations (ie, insulin resistance, increased inflammation, and oxidative stress), circadian rhythm dysregulation, and gut microbial changes that can promote colorectal tumorigenesis. Colorectal cancer (CRC) is the third most incident cancer in the United States. This narrative review examines the effects of intermittend fasting on factors influencing colon tumorigenesis, such as body weight, metabolic and immune markers, circadian rythm, and the gut microbiota in humans. Findings suggest that intermittent fasting regimens can lead to weight loss and shifts in metabolic markers, which could be preventive for CRC but effects on the gut microbiota composition and functions still remains elusive.

Beta-hydroxybutyrate alters bovine preimplantation embryo development through transcriptional and epigenetic mechanisms†

Developing embryos are susceptible to fluctuations in the nutrients and metabolites concentrations within the reproductive tract, which can lead to alterations in their developmental trajectory. Ketotic dairy cows have diminished fertility, and elevated levels of the ketone body beta-hydroxybutyrate (BHB) have been associated with poor embryonic development. We used an in vitro model based on either in vitro fertilization (IVF) or parthenogenesis to investigate the effects of BHB on the preimplantation bovine embryo development, epigenome, and transcriptome. Embryo culture medium was supplemented with BHB at a similar concentration to that present in the blood of cows suffering with severe ketosis, followed by analysis of blastocysts formation rate, diameter, total number of cells, levels of H3K9 beta-hydroxybutyrylation (H3K9bhb), apoptosis, and transcriptional alterations. As a result, we observed that BHB reduced the blastocysts rates, the diameter and the total number of cells in both parthenotes and IVF embryos. Exposure to BHB for either 3 or 7 days greatly increased the H3K9bhb levels in parthenotes at the 8-cells and blastocyst stages, and affected the expression of HDAC1, TET1, DNMT1, KDM6B, NANOG, and MTHFD2 genes. Additionally, culture of IVF embryos with BHB for 7 days dramatically increased H3K9bhb and reduced NANOG in blastocysts. RNA-seq analysis of IVF blastocysts revealed that BHB modulated the expression of 118 genes, which were involved with biological processes such as embryonic development, implantation, reproduction, proliferation, and metabolism. These findings provided valuable insights into the mechanisms through which BHB disrupts preimplantation embryonic development and affects the fertility in dairy cows.

Self-Reported Weekend Temporal Eating Patterns of American Adults Differ From Weekday: National Health and Nutrition Examination Surveys: 2015-2020 Prepandemic

BACKGROUND

Weekend-weekday differences in time of ingestive events may be implicated in adverse metabolic and health outcomes. However, little is known about the nature of weekend-weekday differences in temporal eating behaviors of the US adult population.

OBJECTIVE

The study aimed to examine weekend-weekday differences in temporal and energy characteristics of ingestive events self-reported by American adults.

DESIGN

Observational; within-person comparative.

PARTICIPANTS/SETTING

The data were from the National Health and Nutrition Examination Surveys (NHANES) 2015-March 2020 (pre-pandemic) for ≥20-year-old adults who provided 1 weekday (M-Th) and 1 weekend (F, S, Su) 24-h dietary recall (n = 3564 men and 3823 women).

MAIN OUTCOME MEASURES

Prespecified primary temporal outcomes were recalled: time of ingestive events, and the duration of ingestive and fasting windows. Secondary outcomes included frequency and energy characteristics of ingestive events.

STATISTICAL ANALYSIS PERFORMED

Gender-specific, survey-weighted, multiple linear regression models that accounted for complex survey design with dummy covariates for weekend/weekday, mode of recall administration (in-person on day 1 and telephone on day 2), and a respondent-specific fixed intercept.

RESULTS

In both men and women, the weekend recalled time of first ingestive event, breakfast, and lunch were later than weekday (P ≤ .0008); however, no statistically significant differences were observed in time of dinner and the last eating episode. The mean weekend ingestive window (interval between the time of first and last eating events of the day) was shorter by 24 minutes (95% confidence interval [CI], -32, -11) in men and 18 minutes (95% CI, -20, -15) in women, and the mean overnight fasting window was correspondingly longer (P ≤ .0001). No statistically significant differences were observed between weekend and weekday frequency of ingestive events. Energy density of weekend food selections reported by women, and of beverages by men, was found to be higher than weekday (P ≤ .002).

CONCLUSIONS

Weekend ingestive patterns were characterized by later time of first ingestive event, breakfast, and lunch, and selection of higher-energy-density foods and beverages.

Cross-sectional association of irregular dietary habits with glycemic control and body mass index among people with diabetes

AIMS/INTRODUCTION

To determine the association of irregular dietary habits with HbA1c and body mass index (BMI) in people with diabetes.

MATERIALS AND METHODS

We included 4,421 people with diabetes aged 20-74 years (type 1 diabetes (T1D), 19.1%) who answered a questionnaire at mealtime. Adjusted least square means in HbA1c and BMI in patients with irregular dietary habits: "irregular mealtimes (irregular)," "skipping breakfast (SB)," and "late dinner (LD)" were compared to those with "regular dietary habits (regular)." Multivariable logistic regression analyses were performed to examine the association of irregular dietary habits with HbA1c ≥ 7% and BMI ≥25 kg/m2.

RESULTS

HbA1c was significantly higher for "irregular" in both sexes and for "LD" in women than those of "regular" in people with T1D. HbA1c was significantly higher for "LD," and BMI was higher for almost all irregular dietary habits than those of "regular" in people with type 2 diabetes (T2D). Odds ratios (ORs) for HbA1c ≥7% were 3.20 (95% confidence interval (CI), 1.30-7.89) for T1D women with "irregular" and 1.73 (1.20-2.49) and 2.20 (1.14-3.65) for T2D men and women with "LD," respectively. ORs for BMI ≥25 kg/m2 were 1.60 (95% CI, 1.15-2.22) for T2D men with "irregular" and 1.43 (1.02-2.01) and 2.11 (1.21-3.65) for T2D women and men with "LD," respectively.

CONCLUSIONS

Irregular mealtimes are associated with poor glycemic control in T1D women and are associated with obesity in T2D men. Furthermore, a late dinner was associated with high HbA1c levels and BMI in people with T2D.

Effects of the periodic fasting-mimicking diet on health, lifespan, and multiple diseases: a narrative review and clinical implications

Dietary restriction and fasting have been recognized for their beneficial effects on health and lifespan and their potential application in managing chronic metabolic diseases. However, long-term adherence to strict dietary restrictions and prolonged fasting poses challenges for most individuals and may lead to unhealthy rebound eating habits, negatively affecting overall health. As a result, a periodic fasting-mimicking diet (PFMD), involving cycles of fasting for 2 or more days while ensuring basic nutritional needs are met within a restricted caloric intake, has gained widespread acceptance. Current research indicates that a PFMD can promote stem cell regeneration, suppress inflammation, extend the health span of rodents, and improve metabolic health, among other effects. In various disease populations such as patients with diabetes, cancer, multiple sclerosis, and Alzheimer's disease, a PFMD has shown efficacy in alleviating disease symptoms and improving relevant markers. After conducting an extensive analysis of available research on the PFMD, it is evident that its advantages and potential applications are comparable to other fasting methods. Consequently, it is proposed in this review that a PFMD has the potential to fully replace water-only or very-low-energy fasting regimens and holds promise for application across multiple diseases.

Intermittent Fasting Protects Against the Progression from Acute Kidney Injury to Chronic Kidney Disease

Acute kidney injury (AKI) is a major but often underestimated risk factor for the development of chronic kidney disease (CKD). Exploring innovative approaches to prevent this progression is critical. Intermittent fasting (IF), recognized for its metabolic and anti-inflammatory benefits, may offer protective effects in this context. Using a unilateral ischemia-reperfusion injury (UIRI) model in male C57BL/6 mice, we evaluated the impact of IF on tubulointerstitial fibrosis and tubular epithelial-mesenchymal transition (EMT) over 8 weeks. Mice in the IF group followed a 5:2 regimen, fasting for 24 h twice weekly. Four groups were studied: control, IF, UIRI, and IF + UIRI. The UIRI group exhibited increased fibrosis and EMT, both of which were significantly attenuated in the IF + UIRI group. IF also reduced levels of TGF-β1, phosphorylated NF-κB p65, inflammatory cytokines, and F4/80-positive macrophages, along with markers of oxidative stress. These findings highlight IF's ability to mitigate fibrosis and EMT through reductions in inflammation and oxidative stress during AKI-to-CKD progression. Our study suggests that IF may serve as a promising dietary strategy to prevent AKI from advancing into CKD.

The effects of intermittent fasting on antioxidant and inflammatory markers and liver enzymes in postmenopausal, overweight and obese women with rheumatoid arthritis: a randomized controlled trial

Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting postmenopausal women. This study investigated the effects of intermittent fasting (IF) on antioxidant and inflammatory markers and liver enzymes in postmenopausal, overweight and obese women with RA. This 8-week randomized controlled trial included 44 postmenopausal women with RA divided into an intervention group following a 16:8 IF diet and a control group maintaining their usual diet and received recommendations for healthy eating. Inflammatory indices, oxidative stress markers, and liver enzymes were measured at baseline and post intervention. The IF group showed significant decreases in serum malondialdehyde (MDA) levels (P = 0.02) and neutrophil-to-lymphocyte ratio (P = 0.018) and increased catalase levels (P = 0.004) compared to the control group. Liver enzymes aspartate transaminase (AST) and alanine transaminase (ALT) also decreased significantly in the IF group (P = 0.02 and P = 0.03, respectively). No significant differences were observed in the other measured parameters between groups. In conclusion, the 16:8 IF diet demonstrated beneficial effects on some oxidative stress markers, inflammatory indices, and liver enzymes in postmenopausal, overweight, and obese women with RA. These findings suggest that IF may be an effective non-pharmacological intervention for managing RA in this population, potentially addressing both primary disease symptoms and associated metabolic complications. Further research is needed to elucidate the long-term effects and mechanisms of IF in the management of RA.

Assessing the impact of intermittent fasting and a low-carbohydrate-high-protein diet on metabolic health and pancreatic histopathology in type 2 diabetic rat model

Objective

The current study was conducted to investigate the effect of intermittent fasting (IF) with a low-carbohydrate-high-protein (LCHP) diet on blood glucose control in streptozotocin (STZ)-nicotinamide-induced type 2 diabetic rats (DR).

Methods

Thirty male Wistar rats were divided into six groups (n = 5) including a group of normal rats (NR) that received a control diet (CD) (50% carbohydrates, 17% protein, and 33% fat) with ad libitum (AL) feeding. The remaining 5 groups were DR injected with STZ and fed on CD or LCHP diet (40% carbohydrates, 30% protein, and 30% fat) for 6 weeks, either AL or IF (with a time-restricted feeding of 16 h followed by 8 h feeding period). There was a standard control group treated with metformin and fed on CD with AL feeding. A random blood glucose was measured. Changes in body weight and feed intake (FI) were monitored weekly.

Results

Feeding rats on LCHP and IF and their combination significantly reduced FI, body weight gain, blood glucose (P < 0.001), and improved insulin resistance (P < 0.05) with no effect on the insulin levels (P > 0.05). LCHP and IF decreased the levels of triglycerides and very-low-density lipoprotein and showed a possible protection against atherosclerosis by reducing the atherogenic index (P < 0.01). Furthermore, LCHP+IF greatly alleviates the pancreatic histopathological changes induced by STZ and showed the normal histological structure of the Langerhans islets.

Conclusion

IF with a LCHP diet could be effectively used in improving the indicators of glucose control, and reversing pancreatic histopathological alterations in type 2 diabetes.

Mechanisms of time-restricted feeding-induced neuroprotection and neuronal plasticity in ischemic stroke as a function of circadian rhythm

Time-restricted feeding (TRF) is known to promote longevity and brain function, and potentially prevent neurological diseases. Animal studies show that TRF enhances brain-derived neurotrophic factor (BDNF) signaling and regulates autophagy and neuroinflammation, supporting synaptic plasticity, neurogenesis and neuroprotection. Feeding/fasting paradigms influence the circadian cycle, with TRF aligning circadian cycle-related gene expression, and thus altering physiological processes. Emerging evidence highlights the role of gut microbiota in neuronal plasticity, based on the observation that TRF significantly alters gut microbiota composition. Hence, the gut-brain axis may be crucial for maintaining cognitive functions and presents a potential therapeutic target for TRF-mediated neuroprotection. In the context of ischemic stroke where neuronal damage is extensive, TRF can be a preconditioning strategy to enhance synaptic plasticity and neuronal resilience, thus improving outcomes after stroke. This review discussed the link between TRF and circadian regulation in neuronal plasticity and its implications for recovery after stroke.

Effects of time-restricted feeding (TRF)-model of intermittent fasting on adipose organ: a narrative review

Time-restricted feeding (TRF), an intermittent fasting approach involving a shortened eating window within 24 h, has gained popularity as a weight management approach. This review addresses how TRF may favor fat redistribution and the function of the adipose organ. TRF trials (mainly 16:8 model, with a duration of 5-48 weeks) reported a significant weight loss (1.2-10.2%, ~ 1.4-9.4 kg), with a considerable decrease in total fat mass (1.6-21%, ~ 0.5-7 kg) and visceral adipose compartment (VAC, 11-27%) in overweight and obese subjects. Experimental TRF in normal-fed and obesogenic-diet-fed mice and rats (with a fasting duration ranging between 9 and 21 h within 1-17 weeks) reported a significant reduction in body weight (~ 7-40%), total fat mass (~ 17-71%), and intrahepatic fat (~ 25-72%). TRF also improves VAC and subcutaneous adipose compartment (SAC) function by decreasing adipocyte size, macrophage infiltration, M1-macrophage polarity, and downregulating inflammatory genes. In conclusion, beyond its effect on body weight loss, total fat mass, and intrahepatic fat accumulation, TRF favors adipose organ fat redistribution in overweight and obese subjects by decreasing VAC and improving the function of VAC and SAC.

Impact of dietary ingredients on radioprotection and radiosensitization: a comprehensive review

Radiation exposure poses significant health risks, particularly in radiotherapy and nuclear accidents. Certain dietary ingredients offer potential radioprotection and radiosensitization. In this review, we explore the impact of dietary ingredients, including vitamins, minerals, antioxidants, and other bioactive compounds, on radiation sensitivity and their potential for radioprotection. Radiosensitizers reoxygenate hypoxic tumor cells, increase the radiolysis of water molecules, and regulate various molecular mechanisms to induce cytotoxicity and inhibit DNA repair in irradiated tumor cells. Several dietary ingredients, such as vitamins C, E, selenium, and phytochemicals, show promise in protecting against radiation by reducing radiation-induced oxidative stress, inflammation, and DNA damage. Radioprotectors, such as ascorbic acid, curcumin, resveratrol, and genistein, activate and modulate various signaling pathways, including Keap1-Nrf2, NF-κB, PI3K/Akt/mammalian target of rapamycin (mTOR), STAT3, and mitogen-activated protein kinase (MAPK), in response to radiation-induced oxidative stress, regulating inflammatory cytokine expression, and promoting DNA damage repair and cell survival. Conversely, natural dietary radiosensitizers impede these pathways by enhancing DNA damage and inducing apoptosis in irradiated tumor cells. Understanding the molecular basis of these effects may aid in the development of effective strategies for radioprotection and radiosensitization in cancer treatment. Dietary interventions have the potential to enhance the efficacy of radiation therapy and minimize the side effects associated with radiation exposure.

Work Around the Clock: How Work Hours Induce Social Jetlag and Sleep Deficiency

A growing body of evidence has placed an increasing emphasis on how sleep affects health. Not only does insufficient sleep make one subjectively feel worse, but is associated with chronic diseases that are considered epidemics in industrialized nations. This is partly caused by the growing need for prolonged work and social schedules, exemplified by shift work, late-night weekends, and early morning work/school start times (social jetlag). Here, we consider fundamental relationships between the circadian clock and biologic processes and discuss how common practices, such as shift work and social jetlag, contribute to sleep disruption, circadian misalignment, and adverse health outcomes.

The gut-brain-metabolic axis: exploring the role of microbiota in insulin resistance and cognitive function

The gut-brain-metabolic axis has emerged as a critical area of research, highlighting the intricate connections between the gut microbiome, metabolic processes, and cognitive function. This review article delves into the complex interplay between these interconnected systems, exploring their role in the development of insulin resistance and cognitive decline. The article emphasizes the pivotal influence of the gut microbiota on central nervous system (CNS) function, demonstrating how microbial colonization can program the hypothalamic-pituitary-adrenal (HPA) axis for stress response in mice. It further elucidates the mechanisms by which gut microbial carbohydrate metabolism contributes to insulin resistance, a key factor in the pathogenesis of metabolic disorders and cognitive impairment. Notably, the review highlights the therapeutic potential of targeting the gut-brain-metabolic axis through various interventions, such as dietary modifications, probiotics, prebiotics, and fecal microbiota transplantation (FMT). These approaches have shown promising results in improving insulin sensitivity and cognitive function in both animal models and human studies. The article also emphasizes the need for further research to elucidate the specific microbial species and metabolites involved in modulating the gut-brain axis, as well as the long-term effects and safety of these therapeutic interventions. Advances in metagenomics, metabolomics, and bioinformatics are expected to provide deeper insights into the complex interactions within the gut microbiota and their impact on host health. Overall, this comprehensive review underscores the significance of the gut-brain-metabolic axis in the pathogenesis and treatment of metabolic and cognitive disorders, offering a promising avenue for the development of novel therapeutic strategies targeting this intricate system.

A biological rhythm in the hypothalamic system links sleep-wake cycles with feeding-fasting cycles

The hypothalamus senses the appetite-regulating hormones and also coordinates the metabolic function in alignment with the circadian rhythm. This alignment is essential to maintain the physiological conditions that prevent clinically important comorbidities, such as obesity or type-2 diabetes. However, a complete model of the hypothalamus that relates food intake with circadian rhythms and appetite hormones has not yet been developed. In this work, we present a computational model that accurately allows interpreting neural activity in terms of hormone regulation and sleep-wake cycles. We used a conductance-based model, which consists of a system of four differential equations that considers the ionotropic and metabotropic receptors, and the input currents from homeostatic hormones. We proposed a logistic function that fits available experimental data of insulin hormone concentration and added it into a short-term ghrelin model that served as an input to our dynamical system. Our results show a double oscillatory system, one synchronized by light-regulated sleep-wake cycles and the other by food-regulated feeding-fasting cycles. We have also found that meal timing frequency is highly relevant for the regulation of the hypothalamus neurons. We therefore present a mathematical model to explore the plausible link between the circadian rhythm and the endogenous food clock.

Effect of fasting-induced headache on calcitonin gene related peptide (CGRP) and other clinical biomarkers on the first day of Ramadan: Sub-analysis from a randomized open label clinical trial

BACKGROUND

Fasting-induced headaches (FIHs) have been shown to occur on the first day of Ramadan and clearly decline thereafter. Despite the wealth of knowledge about different types of headaches (e.g., migraine-, cluster-, and tension-type headaches), research on the mechanism underlying FIHs, as well as their treatment, remains scarce. Our study aimed to investigate any association between FIHs during the first day of Ramadan and potential headache-related biomarkers, including fasting blood glucose (FBG), C-reactive protein (CRP), magnesium, vitamin B9, vitamin B12, homocysteine, and calcitonin gene related peptide (CGRP), and to assess whether a prophylactic use of paracetamol may influence these biomarkers.

METHODS

As part of a randomized, open-label clinical trial that evaluated the effect of paracetamol as a prophylactic therapy for FIH, blood samples from stratified subjects in the prophylaxis and control groups were withdrawn while fasting after the 1st dose of paracetamol (in the prophylaxis group) and prior to reporting headache occurrence.

RESULTS

Plasma and serum were separated for 61 subjects; 31 and 30 subjects from the prophylaxis and control groups, respectively. Overall, no significant differences were found in the levels of FBG, CRP, magnesium, vitamin B9, and vitamin B12 in headache-suffering subjects compared to those without headache despite the use of paracetamol for prophylaxis. Homocysteine, however, was significantly reduced in all subjects who experienced FIH compared to those without headache (median 6.9 [1.6] vs. 7.7 [2.7] umol/L; p = 0.041). On the contrary, when the CGRP was measured using immunoassay, it was found to be significantly elevated in all headache-suffering subjects compared to those without headache (median 126.1 [17.7] vs. 105.8 [19.6] pg/mL; p ≤ 0.0001). This difference was maintained upon comparing the headache to non-headache subjects in both the prophylaxis (median 121.5 [15.4] vs. 105.8 [9.4] pg/mL; p < 0.01) and control groups (median 128.5 [28.3] vs. 105.8 [23.8] pg/mL; p < 0.01). Additionally, an elevated CGRP level was found to increase the odds of having a FIH [OR = 1.32; 95%CI 1.06-1.22].

CONCLUSIONS

Our findings revealed the role of CGRP in FIHs for the first time and suggest further investigation in signaling pathways downstream CGRP receptors. Furthermore, the modulation CGRP or CGRP receptors could have a clinical application in the prevention of FIHs.

TRIAL REGISTRATION

This study was registered with the Saudi Food and Drug Authority in the Saudi Clinical Trials Registry (SCTR; No. 22122102).

The association between breakfast frequency and diabetes incidence in middle-aged women: Results from the MTC study

BACKGROUND AND AIMS

Breakfast consumption could have a synchronizer role in chronobiological functions. Across observational studies, the assessment of breakfast frequency consumption is heterogeneous, therefore consensus on the relation between of weekly frequency of breakfast consumption and the risk of diabetes is unclear. We examined the relation between weekly breakfast frequency consumption and the incidence of diabetes in middle-age women.

METHODS AND RESULTS

Since baseline (2006-2008) we prospectively followed 71,373 women from the Mexican Teachers' Cohort. Participants were classified according to breakfast consumption frequency of 0, 1-3, 4-6, or 7 days/week. Diabetes was identified by self-report and clinical-administrative databases. We used Cox proportional hazards multivariable models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for breakfast frequency and diabetes adjusting for covariates. Stratified analyses were performed for age, birth weight, ethnicity, and physical activity. We identified 3613 new diabetes cases between baseline and 2014. The prevalence of daily breakfast consumers was 25%. The median follow-up was 2.2 years, interquartile range 1.8-3.8 years. Relative to women who skipped breakfast, those who consumed breakfast every day had a 12% lower risk of diabetes (multivariable HR = 0.88; 95% CI 0.78, 0.99; p-trend = 0.0018). One additional day per week of breakfast was associated with a lower risk of diabetes (HR = 0.98; 95% CI 0.97, 0.99). In stratified analysis, the observed inverse relation appeared to be stronger in women aged ≥40 years and in indigenous women.

CONCLUSIONS

Breakfast frequency was inversely associated with the incidence of diabetes independently of lifestyle factors. Regular breakfast consumption may be a potential component of diabetes prevention.

Determinants of breakfast skipping among pregnant women from South Ethiopia Gamo Zone: a case-control study

Skipping breakfast during pregnancy presents several challenges and potential health risks for both the mother and her baby. Breakfast plays a crucial role in providing essential nutrients and energy after an overnight fast. Skipping breakfast during pregnancy creates an unhealthy environment for the fetus. Thus, this study aimed to identify the determinants of breakfast skipping among pregnant women. An unmatched, community-based case-control study was conducted among 116 randomly selected cases (breakfast skippers) and 232 neighboring controls (regular breakfast consumers). Data was collected using pre-tested interviewer-administered structured questionnaire. Binary logistic regression analysis was employed to determine predictors of breakfast skipping using STATA version 16. The odds of non-formal education (AOR = 3.92; 95% CI: 1.75, 8.78), low socioeconomic status (AOR = 2.93; 95% CI: 1.12, 7.68), poor dietary knowledge (AOR = 2.89; 95% CI: 1.29, 6.47), and experiencing morning sickness (AOR = 2.57; 95% CI: 1.13, 5.84) were higher among cases than controls. The odds of breakfast skipping were higher for every increase in family size (AOR = 1.65; 95% CI: 1.25, 2.18), but decrease with every unit increase in mid-upper arm circumference (AOR = 0.58; 95% CI: 0.46, 0.72) and weekly frequency of drinking coffee leaf tea beverage (AOR = 0.84; 95% CI: 0.78, 0.89). Findings of this study showed that poor economic status, lack of formal education, poor dietary knowledge, having morning sickness, having large family size, maternal nutritional status, and frequent consumption of coffee leaf tea beverage were significantly associated with breakfast skipping among pregnant women. Thus, efforts should focus on improving dietary awareness during pregnancy, strengthening dietary counseling during antenatal care, enhancing access to contraceptive services, and ensuring timely management of morning sickness.

The Influence of Non-Pharmacological and Pharmacological Interventions on the Course of Autosomal Dominant Polycystic Kidney Disease

Polycystic kidney disease (PKD) includes autosomal dominant (ADPKD) and autosomal recessive (ARPKD) forms, both of which are primary genetic causes of kidney disease in adults and children. ADPKD is the most common hereditary kidney disease, with a prevalence of 329 cases per million in Europe. This condition accounts for 5-15% of end-stage chronic kidney disease (ESKD) cases, and in developed countries such as Poland, 8-10% of all dialysis patients have ESKD due to ADPKD. The disease is caused by mutations in the PKD1 and PKD2 genes, with PKD1 mutations responsible for 85% of cases, leading to a more aggressive disease course. Recent research suggests that ADPKD involves a metabolic defect contributing to cystic epithelial proliferation and cyst growth. Aim: This review explores the interplay between metabolism, obesity, and ADPKD, discussing dietary and pharmacological strategies that target these metabolic abnormalities to slow disease progression. Conclusion: Metabolic reprogramming therapies, including GLP-1 analogs and dual agonists of GIP/GLP-1 or glucagon/GLP-1 receptors, show promise, though further research is needed to understand their potential in ADPKD treatment fully.

Daily Brain Metabolic Rhythms of Wild Nocturnal Bats

Circadian rhythms are found in a wide range of organisms and have garnered significant research interest in the field of chronobiology. Under normal circadian function, metabolic regulation is temporally coordinated across tissues and behaviors within a 24 h period. Metabolites, as the closest molecular regulation to physiological phenotype, have dynamic patterns and their relationship with circadian regulation remains to be fully elucidated. In this study, untargeted brain metabolomics was employed to investigate the daily rhythms of metabolites at four time points corresponding to four typical physiological states in Vespertilio sinensis. Key brain metabolites and associated physiological processes active at different time points were detected, with 154 metabolites identified as rhythmic. Analyses of both metabolomics and transcriptomics revealed that several important physiological processes, including the pentose phosphate pathway and oxidative phosphorylation, play key roles in regulating rhythmic physiology, particularly in hunting and flying behaviors. This study represents the first exploration of daily metabolic dynamics in the bat brain, providing insights into the complex regulatory network of circadian rhythms in mammals at a metabolic level. These findings serve as a valuable reference for future studies on circadian rhythms in nocturnal mammals.

The 5:2 Diet Affects Markers of Insulin Secretion and Sensitivity in Subjects with and without Type 2 Diabetes-A Non-Randomized Controlled Trial

This non-randomized controlled trial aimed to compare the effect of the 5:2 diet on insulin levels as a primary outcome and markers of insulin secretion (connecting peptide (C-peptide) and insulin-like growth factor binding protein-1 (IGFBP-1)) and sensitivity (Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)), as well as body composition as secondary outcomes in overweight/obese individuals with and without type 2 diabetes (T2D). Ninety-seven participants (62% women), 35 with T2D and 62 BMI- and waist-matched controls without T2D, followed the 5:2 diet (two days per week of fasting) for six months with a 12-month follow-up. At six months, there was no loss to follow-up in the T2D group, whereas four controls discontinued this study. Overall, 82% attended the 12-month follow-up. After the intervention, insulin levels decreased in the control group and glucose decreased in the T2D group, while C-peptide, HOMA-IR, waist circumference, BMI, trunk, and total fat% decreased in both groups. Furthermore, low IGFBP-1, indicating hyperinsulinemia, improved in the T2D group. The changes in fasting glucose and waist measurement were significantly more improved in the T2D group than in the controls. Persistent positive effects were observed at the 12-month follow-up. The 5:2 diet for six months was feasible and efficient to reduce markers of insulin secretion and resistance and therefore holds promise as management of overweight/obesity in subjects with and without T2D.

Time-Restricted Feeding Reduces Atherosclerosis in LDLR KO Mice but Not in ApoE Knockout Mice

BACKGROUND

Dyslipidemia increases cardiovascular disease risk, the leading cause of death worldwide. Under time-restricted feeding (TRF), wherein food intake is restricted to a consistent window of <12 hours, weight gain, glucose intolerance, inflammation, dyslipidemia, and hypercholesterolemia are all reduced in mice fed an obesogenic diet. LDLR (low-density lipoprotein receptor) mutations are a major cause of familial hypercholesterolemia and early-onset cardiovascular disease.

METHODS

We subjected benchmark preclinical models, mice lacking LDLR-knockout or ApoE knockout to ad libitum feeding of an isocaloric atherogenic diet either ad libitum or 9 hours TRF for up to 13 weeks and assessed disease development, mechanism, and global changes in hepatic gene expression and plasma lipids. In a regression model, a subset of LDLR-knockout mice were ad libitum fed and then subject to TRF.

RESULTS

TRF could significantly attenuate weight gain, hypercholesterolemia, and atherosclerosis in mice lacking the LDLR-knockout mice under experimental conditions of both prevention and regression. In LDLR-knockout mice, increased hepatic expression of genes mediating β-oxidation during fasting is associated with reduced VLDL (very-low-density lipoprotein) secretion and lipid accumulation. Additionally, increased sterol catabolism coupled with fecal loss of cholesterol and bile acids contributes to the atheroprotective effect of TRF. Finally, TRF alone or combined with a cholesterol-free diet can reduce atherosclerosis in LDLR-knockout mice. However, mice lacking ApoE, which is an important protein for hepatic lipoprotein reuptake do not respond to TRF.

CONCLUSIONS

In a preclinical animal model, TRF is effective in both the prevention and regression of atherosclerosis in LDLR knockout mice. The results suggest TRF alone or in combination with a low-cholesterol diet can be a lifestyle intervention for reducing cardiovascular disease risk in humans.

Ketogenic Interventions in Autosomal Dominant Polycystic Kidney Disease: A Comprehensive Review of Current Evidence

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a genetic disorder characterized by the development and enlargement of multiple kidney cysts, leading to progressive kidney function decline. To date, Tolvaptan, the only approved treatment for this condition, is able to slow down the loss of annual kidney function without stopping the progression of the disease. Furthermore, this therapy is approved only for patients with rapid disease progression and its compliance is problematic because of the drug's impact on quality of life. The recent literature suggests that cystic cells are subject to several metabolic dysregulations, particularly in the glucose pathway, and mitochondrial abnormalities, leading to decreased oxidative phosphorylation and impaired fatty acid oxidation. This finding paved the way for new lines of research targeting potential therapeutic interventions for ADPKD. In particular, this review highlights the latest studies on the use of ketosis, through ketogenic dietary interventions (daily calorie restriction, intermittent fasting, time-restricted feeding, ketogenic diets, and exogenous ketosis), as a potential strategy for patients with ADPKD, and the possible involvement of microbiota in the ketogenic interventions' effect.

Sleep traits and breast cancer risk: a two-sample Mendelian randomization study

Globally, breast cancer continues to be the leading cause of cancer-related incidence and mortality among females. Research has shown that sleep patterns significantly influence tumor onset and progression. In this research, the association was examined through the application of a two-sample Mendelian randomization (MR) approach. For the analysis of seven sleep patterns, genetic tools were sourced from both the UK Biobank and 23andMe, including morning/evening person (chronotype) n = 177,604, morning person (chronotype) n = 248,094, daytime dozing/sleepiness n = 193,472, getting up in the morning n = 193,717, and sleeplessness n = 193,987; sleep duration n = 192,810; and nap during the day n = 166,853. The Breast Cancer Association Consortium (BCAC) supplied genome-wide association studies (GWAS) data, including 133,384 breast cancer cases and 113,789 controls, alongside subtype-specific data with 106,278 cases and 91,477 controls. We discovered that chronotype encompasses both morning and evening types contributes to the risk of overall breast cancer. While daytime dozing and morning person (chronotype) are linked to a lower risk of breast cancer in general, In subtype-specific analyses, morning person (chronotype) was negatively associated with luminal B, HER2-negative-like, and daytime dozing was negatively correlated with luminal A-like, luminal B-like, and HER2-enriched-like. The study corroborates that chronotype is a danger element for breast cancer, aligning with previous observational findings. The association between being a morning person (chronotype) or having daytime dozing and a decreased risk of breast cancer underscores the significance of sleep patterns in formulating strategies for cancer prevention.

Time-Restricted Feeding Protects against Renal Ischemia-Reperfusion Injury in Mice

Ischemia-reperfusion injury (IRI) in the kidneys is a major cause of acute kidney injury (AKI). Time-restricted feeding (TRF), known for its metabolic health benefits and alleviation of various chronic diseases without calorie restriction, was investigated for its potential protective effects against IRI-induced AKI. Male C57BL/6 mice underwent unilateral IRI, with their kidneys collected after two days. For two weeks before IRI induction, the TRF group had unlimited access to standard chow but within an 8-hour feeding window during the dark cycle. The study groups were Control, TRF, IRI, and TRF + IRI. In the TRF + IRI group, tubular damage scores significantly decreased compared to the IRI group. Furthermore, the TRF + IRI mice had lower levels of phosphorylated NF-κB and fewer F4/80-positive macrophages than the IRI group. Oxidative stress markers for lipids and proteins were also notably lower in the TRF + IRI group. Additionally, TUNEL-positive tubular cells and cleaved caspase-3 expression were reduced in the TRF + IRI group. Without calorie restriction, TRF mitigated renal damage by reducing inflammation, oxidative stress, and tubular apoptosis in renal IRI. This suggests that TRF could be a promising dietary strategy to prevent IRI-induced AKI.

Pioneering new frontiers in circadian medicine chronotherapies for cardiovascular health

Cardiovascular disease (CVD) is a global health concern. Circadian medicine improves cardiovascular care by aligning treatments with our body's daily rhythms and their underlying cellular circadian mechanisms. Time-based therapies, or chronotherapies, show special promise in clinical cardiology. They optimize treatment schedules for better outcomes with fewer side effects by recognizing the profound influence of rhythmic body cycles. In this review, we focus on three chronotherapy areas (medication, light, and meal timing) with potential to enhance cardiovascular care. We also highlight pioneering research in the new field of rest, the gut microbiome, novel chronotherapies for hypertension, pain management, and small molecules that targeting the circadian mechanism.

Time-restricted feeding protects against cisplatin-induced acute kidney injury in mice

BACKGROUND

Time-restricted feeding (TRF), devoid of calorie restriction, is acknowledged for promoting metabolic health and mitigating various chronic metabolic diseases. While TRF exhibits widespread benefits across multiple tissues, there is limited exploration into its impact on kidney function. In this study, our aim was to investigate the potential ameliorative effects of TRF on kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI).

METHODS

Cisplatin-induced AKI was induced through intraperitoneal injection of cisplatin into C57BL/6 male mice. Mice undergoing TRF were provided unrestricted access to standard chow daily but were confined to an 8-hour feeding window during the dark cycle for 2 weeks before cisplatin injection. The mice were categorized into four groups: control, TRF, cisplatin, and TRF + cisplatin.

RESULTS

The tubular damage score and serum creatinine levels were significantly lower in the TRF + cisplatin group compared to the cisplatin group. The TRF + cisplatin group exhibited reduced expression of phosphorylated nuclear factor kappa B, inflammatory cytokines, and F4/80-positive macrophages compared to the cisplatin group. Furthermore, oxidative stress markers for DNA, protein, and lipid were markedly decreased in the TRF + cisplatin group compared to the cisplatin group. TUNEL-positive tubular cells, cleaved caspase-3 expression, and the Bax/Bcl-2 ratio in the TRF + cisplatin group were lower than those in the cisplatin group.

CONCLUSION

TRF, without calorie restriction, effectively mitigated kidney damage by suppressing inflammatory reactions, oxidative stress, and tubular apoptosis in a mouse model of cisplatin-induced AKI. TRF holds promise as a novel dietary intervention for preventing cisplatin-induced AKI.

Microbiome and physical activity

Regular physical activity promotes health benefits and contributes to develop the individual biological potential. Chronical physical activity performed at moderate and high-intensity is the intensity more favorable to produce health development in athletes and improve the gut microbiota balance. The athletic microbiome is characterized by increased microbial diversity and abundance as well as greater phenotypic versatility. In addition, physical activity and microbiota composition have bidirectional effects, with regular physical activity improving microbial composition and microbial composition enhancing physical performance. The improvement of physical performance by a healthy microbiota is related to different phenotypes: i) efficient metabolic development, ii) improved regulation of intestinal permeability, iii) favourable modulation of local and systemic inflammatory and efficient immune responses, iv) efective regulation of systemic pH and, v) protection against acute stressful events such as environmental exposure to altitude or heat. The type of sport, both intensity or volume characteristics promote microbiota specialisation. Individual assessment of the state of the gut microbiota can be an effective biomarker for monitoring health in the medium to long term. The relationship between the microbiota and the rest of the body is bidirectional and symbiotic, with a full connection between the systemic functions of the nervous, musculoskeletal, endocrine, metabolic, acid-base and immune systems. In addition, circadian rhythms, including regular physical activity, directly influence the adaptive response of the microbiota. In conclusion, regular stimuli of moderate- and high-intensity physical activity promote greater diversity, abundance, resilience and versatility of the gut microbiota. This effect is highly beneficial for human health when healthy lifestyle habits including nutrition, hydration, rest, chronoregulation and physical activity.

One Health: Circadian Medicine Benefits Both Non-human Animals and Humans Alike

Circadian biology's impact on human physical health and its role in disease development and progression is widely recognized. The forefront of circadian rhythm research now focuses on translational applications to clinical medicine, aiming to enhance disease diagnosis, prognosis, and treatment responses. However, the field of circadian medicine has predominantly concentrated on human healthcare, neglecting its potential for transformative applications in veterinary medicine, thereby overlooking opportunities to improve non-human animal health and welfare. This review consists of three main sections. The first section focuses on the translational potential of circadian medicine into current industry practices of agricultural animals, with a particular emphasis on horses, broiler chickens, and laying hens. The second section delves into the potential applications of circadian medicine in small animal veterinary care, primarily focusing on our companion animals, namely dogs and cats. The final section explores emerging frontiers in circadian medicine, encompassing aquaculture, veterinary hospital care, and non-human animal welfare and concludes with the integration of One Health principles. In summary, circadian medicine represents a highly promising field of medicine that holds the potential to significantly enhance the clinical care and overall health of all animals, extending its impact beyond human healthcare.

It's About Timing: Contrasting the Metabolic Effects of Early vs. Late Time-Restricted Eating in Humans

PURPOSE OF REVIEW

Time-restricted eating (TRE), a form of intermittent fasting, restricts feeding time across the day, imposing a daily 'eating window'. The time of day when the eating window occurs could result in differential metabolic effects. Here, we describe recent intervention studies in humans assessing the metabolic consequences of an early- (i.e., eating window starting in the early morning) vs. late (i.e., eating window starting after midday)-TRE protocol.

RECENT FINDINGS

Well-controlled studies indicate that both TRE protocols effectively reduce body weight and improve altered glucose metabolism, lipid profile, inflammation, or blood pressure levels. An early-TRE (e-TRE) might have a further positive impact on improving blood glucose, insulin levels, and insulin resistance. However, the studies directly assessing the metabolic consequences of an early- vs. late-TRE have shown dissimilar findings, and more well-controlled clinical trials are needed on the metabolic benefits of these two types of TRE. Evidence suggests that an e-TRE might have enhanced metabolic results, particularly regarding glucose homeostasis. More long-term studies, including larger sample sizes, are needed to assess the metabolic, circadian, and adherence benefits, together with socio-cultural acceptance of both TRE approaches.

The Impact of Exercise on Interleukin-6 to Counteract Immunosenescence: Methodological Quality and Overview of Systematic Reviews

OBJECTIVE

This study evaluated the methodological quality of published systematic reviews on randomized and non-randomized clinical trials to synthesize evidence on the association between IL-6, immunosenescence, and aerobic and/or resistance exercise.

METHOD

The Preferred Reporting Items for Overviews of Systematic Reviews (PRIO-harms) guideline was used, with registration number CRD42022346142-PROSPERO. Relevant databases such as Cochrane Library, PubMed, Web of Science, Scopus, and Google Scholar were searched using English Medical Subject Headings terms. Inclusion criteria were systematic reviews analyzing aerobic exercise, resistance exercise, or a combination of both and assessing IL-6 as a biomarker of cellular immunosenescence in humans. The Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) was employed.

RESULTS

Out of 742 identified articles, 18 were eligible, and 13 were selected for analysis. Sample sizes ranged from 249 to 1421 participants, mostly female, with ages ranging from 17 to 95 years. Aerobic exercise was the most studied type (46.15%), followed by combined exercise (38.46%) and resistance exercise (15.38%). Aerobic exercise showed a statistically significant reduction in IL-6, C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) levels. Among the 13 reviews analyzed using AMSTAR-2, 8 were rated as critically low quality, and 5 were classified as low quality.

CONCLUSION

Aerobic exercise has anti-inflammatory properties and the potential to modulate IL-6, CRP, and TNF-α levels in immunosenescence. However, the limited methodological quality of the analyzed systematic reviews highlights the urgent need for robust, high-quality studies to improve access to information and facilitate evidence-based decision-making in healthcare.

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.

Association of largest meal timing and eating frequency with body mass index and obesity

BACKGROUND AND AIMS

The circadian pattern of eating behaviors has garnered increasing interest as a strategy for obesity prevention and weight loss. It is believed that the benefits stem from aligning food intake with the body's natural daily rhythms. However, the existing body of evidence is limited in scale and scope and there has been insufficient evaluation of temporal eating behaviors, such as the specific time of day in which the highest calorie consumption occurs, meal frequency, and distribution. This research aims to explore the association between the timing of the largest meal of the day and eating frequency with Body Mass Index (BMI) and obesity.

METHODS

Participants (n = 2050, 18-65y) were part of an exploratory cross-sectional and population-based research, with data collection in a virtual environment. Linear regression analyses and restricted cubic splines evaluated differences in BMI associated with independent eating variables [timing of the largest meal, number of meals/day (as continuous and categorical: ≤3 or >3/day), and each largest meal of the day (breakfast/lunch/dinner)]. Logistic regression models were fitted to assess Odds Ratios (OR) and 95 % Confidence Intervals (CI) of obesity associated with the same independent variables.

RESULTS

Our main findings were that the timing of the largest meal and reporting dinner as the largest meal were associated with higher values of BMI (respectively, 0.07 kg/m2 and 0.85 kg/m2) and increased odds of obesity [respectively OR(95%CI):1.04(1.01,1.08), and OR(95%CI):1.67(1.18,2.38)]. Those who realized more than 3 meals/day presented lower values of BMI (-0.14 kg/m2) and 32 % lower odds of having obesity [OR(95%CI):0.68(0.52,0.89)]. Reporting lunch as the largest meal also protected against obesity [OR(95%CI):0.71(0.54,0.93)]. These associations were statistically significant and independent of sex, age, marital status, education level, diet quality, sleep duration, and weekly frequency of physical exercise.

CONCLUSION

Having the largest meal earlier in the day, concentrating the majority of caloric intake during lunch, and consuming more than three meals a day, may present a promising intervention for preventing and treating obesity/overweight.

Design and Rationale of Prolonged Nightly Fasting for Multiple Myeloma Prevention (PROFAST): Protocol for a Randomized Controlled Pilot Trial

BACKGROUND

Obesity is an established, modifiable risk factor of multiple myeloma (MM); yet, no lifestyle interventions are routinely recommended for patients with overweight or obesity with MM precursor conditions. Prolonged nightly fasting is a simple, practical dietary regimen supported by research, suggesting that the synchronization of feeding-fasting timing with sleep-wake cycles favorably affects metabolic pathways implicated in MM. We describe the design and rationale of a randomized controlled pilot trial evaluating the efficacy of a regular, prolonged nighttime fasting schedule among individuals with overweight or obesity at high risk for developing MM or a related lymphoid malignancy.

OBJECTIVE

We aim to investigate the effects of 4-month prolonged nightly fasting on body composition and tumor biomarkers among individuals with overweight or obesity with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), or smoldering Waldenström macroglobulinemia (SWM).

METHODS

Individuals with MGUS, SMM, or SWM aged ≥18 years and a BMI of ≥25 kg/m2 are randomized to either a 14-hour nighttime fasting intervention or a healthy lifestyle education control group. Participants' baseline diet and lifestyle patterns are characterized through two 24-hour dietary recalls: questionnaires querying demographic, comorbidity, lifestyle, and quality-of-life information; and wrist actigraphy measurements for 7 days. Fasting intervention participants are supported through one-on-one telephone counseling by a health coach and automated SMS text messaging to support fasting goals. Primary end points of body composition, including visceral and subcutaneous fat (by dual-energy x-ray absorptiometry); bone marrow adiposity (by bone marrow histology); and tumor biomarkers, specifically M-proteins and serum free light-chain concentrations (by gel-based and serum free light-chain assays), are assessed at baseline and after the 4-month study period; changes therein from baseline are evaluated using a repeated measures mixed-effects model that accounts for the correlation between baseline and follow-up measures and is generally robust to missing data. Feasibility is assessed as participant retention (percent dropout in each arm) and percentage of days participants achieved a ≥14-hour fast.

RESULTS

The PROlonged nightly FASTing (PROFAST) study was funded in June 2022. Participant recruitment commenced in April 2023. As of July 2023, six participants consented to the study. The study is expected to be completed by April 2024, and data analysis and results are expected to be published in the first quarter of 2025.

CONCLUSIONS

PROFAST serves as an important first step in exploring the premise that prolonged nightly fasting is a strategy to control obesity and obesity-related mechanisms of myelomagenesis. In evaluating the feasibility and impact of prolonged nightly fasting on body composition, bone marrow adipose tissue, and biomarkers of tumor burden, this pilot study may generate hypotheses regarding metabolic mechanisms underlying MM development and ultimately inform clinical and public health strategies for MM prevention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05565638; http://clinicaltrials.gov/ct2/show/NCT05565638.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51368.

Short-term periodic restricted feeding elicits metabolome-microbiome signatures with sex dimorphic persistence in primate intervention

Dietary restriction has shown benefits in physiological, metabolic, and molecular signatures associated with aging but is a difficult lifestyle to maintain for most individuals. In mice, a less restrictive diet that allows for cyclical periods of reduced calories mitigates aging phenotypes, yet the effects of such an intervention in a genetically heterogenous, higher-order mammal has not been examined. Here, using middle-aged rhesus macaques matched for age and sex, we show that a regimen of 4 days of low-calorie intake followed by 10 days of ad libitum feeding (4:10 diet) performed in repeating cycles over 12 weeks led to significant loss of weight and fat percentage, despite the free access to food for most of the study duration. We show the 4-day restriction period is sufficient to drive alterations to the serum metabolome characterized by substantial differences in lipid classes. These phenotypes were paralleled by changes in the gut microbiome of restricted monkeys that highlight the involvement of a microbiome-metabolome axis. This regimen shows promising phenotypes, with some sex-dimorphic responses, including residual memory of the diet. As many calorie restriction interventions are difficult to sustain, we propose that this short-term diet may be easier to adhere to and have benefits directly relevant to human aging.

Real-world data of a digitally enabled, time-restricted eating weight management program in public sector workers living with overweight and obesity in the United Kingdom: A service evaluation of the Roczen program

Introduction

The health of the United Kingdom workforce is key; approximately 186 million days are lost to sickness each year. Obesity and type 2 diabetes (T2D) remain major global health challenges. The aim of this retrospective service evaluation was to assess the impact of a digitally enabled, time-restricted eating (TRE) intervention (Roczen Program, Reset Health Ltd) on weight and other health-related outcomes.

Methods

This service evaluation was conducted in people living with overweight/obesity, with 89% referred from public sector employers. Participants were placed on a TRE, low-carbohydrate, moderate protein plan delivered by clinicians and mentors with regular follow up, dietary guidance, goal setting, feedback, and social support.

Results

A total of 660 members enrolled and retention was 41% at 12 months. The majority were female (73.2%), 58.9% were of White ethnicity, with a mean (SD) age of 47.5 years (10.1), and a body mass index of 35.0 kg/m2 (5.7). Data were available for 82 members at 12-month. At 12-month, members mean actual and percentage weight loss was -9.0 kg (7.0; p < 0.001) and -9.2% (6.7, p < 0.001) respectively and waist circumference reduced by -10.3 cm (10.7 p < 0.001), with 45.1% of members achieving ≥10% weight loss. Glycated hemoglobin was significantly improved at 6 months in people living with T2D (-11 mmol/mol [5.7] p = 0.012). Binge eating score significantly reduced (-4.4 [7.0] p = 0.006), despite cognitive restraint increasing (0.37 [0.6] p = 0.006).

Conclusion

Our service evaluation showed that the Roczen program led to clinically meaningful improvements in body weight, health-related outcomes and eating behaviors that were sustained at 12-month.

Seven knowledge gaps in modern biogerontology

About a year ago, members of the editorial board of Biogerontology were requested to respond to a query by the editor-in-chief of the journal as to what one question within their field of ageing research still needs to be asked and answered. This editorial is inspired by the wide range and variety of questions, ideas, comments and suggestions received in response to that query. The seven knowledge gaps identified in this article are arranged into three main categories: evolutionary aspects of longevity, biological survival and death aspects, and heterogeneity in the progression and phenotype of ageing. This is not an exhaustive and exclusive list, and may be modified and expanded. Implications of these knowledge gaps, especially in the context of ongoing attempts to develop effective interventions in ageing and longevity are also discussed.

Misalignment of Circadian Rhythms in Diet-Induced Obesity

The biological clocks of the circadian timing system coordinate cellular and physiological processes and synchronize them with daily cycles. While the central clock in the suprachiasmatic nucleus (SCN) is mainly synchronized by the light/dark cycles, the peripheral clocks react to other stimuli, including the feeding/fasting state, nutrients, sleep-wake cycles, and physical activity. During the disruption of circadian rhythms due to genetic mutations or social and occupational obligations, incorrect arrangement between the internal clock system and environmental rhythms leads to the development of obesity. Desynchronization between the central and peripheral clocks by altered timing of food intake and diet composition leads to uncoupling of the peripheral clocks from the central pacemaker and to the development of metabolic disorders. The strong coupling of the SCN to the light-dark cycle creates a situation of misalignment when food is ingested during the "wrong" time of day. Food-anticipatory activity is mediated by a self-sustained circadian timing, and its principal component is a food-entrainable oscillator. Modifying the time of feeding alone greatly affects body weight, whereas ketogenic diet (KD) influences circadian biology, through the modulation of clock gene expression. Night-eating behavior is one of the causes of circadian disruption, and night eaters have compulsive and uncontrolled eating with severe obesity. By contrast, time-restricted eating (TRE) restores circadian rhythms through maintaining an appropriate daily rhythm of the eating-fasting cycle. The hypothalamus has a crucial role in the regulation of energy balance rather than food intake. While circadian locomotor output cycles kaput (CLOCK) expression levels increase with high-fat diet-induced obesity, peroxisome proliferator-activated receptor-alpha (PPARα) increases the transcriptional level of brain and muscle aryl hydrocarbon receptor nuclear translocator (ARNT)-like 1 (BMAL1) in obese subjects. In this context, effective timing of chronotherapies aiming to correct SCN-driven rhythms depends on an accurate assessment of the SCN phase. In fact, in a multi-oscillator system, local rhythmicity and its disruption reflects the disruption of either local clocks or central clocks, thus imposing rhythmicity on those local tissues, whereas misalignment of peripheral oscillators is due to exosome-based intercellular communication.Consequently, disruption of clock genes results in dyslipidemia, insulin resistance, and obesity, while light exposure during the daytime, food intake during the daytime, and sleeping during the biological night promote circadian alignment between the central and peripheral clocks. Thus, shift work is associated with an increased risk of obesity, diabetes, and cardiovascular diseases because of unusual eating times as well as unusual light exposure and disruption of the circadian rhythm.

Polymorphic phase transitions in triglycerides and their mixtures studied by SAXS/WAXS techniques: In bulk and in emulsions

Triacylglycerols (TAGs) exhibit a monotropic polymorphism, forming three main polymorphic forms upon crystallization: α, β' and β. The distinct physicochemical properties of these polymorphs, such as melting temperature, subcell lattice structure, mass density, etc., significantly impact the appearance, texture, and long-term stability of a wide range products in the food and cosmetics industries. Additionally, TAGs are also of special interest in the field of controlled drug delivery and sustained release in pharmaceuticals, being a key material in the preparation of solid lipid nanoparticles. The present article outlines our current understanding of TAG phase behavior in both bulk and emulsified systems. While our primary focus are investigations involving monoacid TAGs and their mixtures, we also include illustrative examples with natural TAG oils, highlighting the knowledge transfer from simple to intricate systems. Special attention is given to recent discoveries via X-ray scattering techniques. The main factors influencing TAG polymorphism are discussed, revealing that a higher occurrence of structural defects in the TAG structure always accelerates the rate of the α → β polymorphic transformation. Diverse approaches can be employed based on the specific system: incorporating foreign molecules or solid particles into bulk TAGs, reducing drop size in dispersed systems, or using surfactants that remain fluid during TAG particle crystallization, ensuring the necessary molecular mobility for the polymorphic transformation. Furthermore, we showcase the role of TAG polymorphism on a recently discovered phenomenon: the creation of nanoparticles as small as 20 nm from initial coarse emulsions without any mechanical energy input. This analysis underscores how the broader understanding of the TAG polymorphism can be effectively applied to comprehend and control previously unexplored processes of notable practical importance.

Diet-Modifiable Redox Alterations in Ageing and Cancer

With ageing comes some of life's best and worst moments. Those lucky enough to live out into the seventh, eighth, and nineth decades and perhaps beyond have more opportunities to experience the wonders and joys of the world. As the world's population shifts towards more and more of these individuals, this is something to be celebrated. However, it is not without negative consequences. Advanced age also ushers in health decline and the burden of non-communicable diseases such as cancer, heart disease, stroke, and organ function decay. Thus, alleviating or at least dampening the severity of ageing as a whole, as well as these individual age-related disorders will enable the improvement in lifespan and healthspan. In the following chapter, we delve into hypothesised causes of ageing and experimental interventions that can be taken to slow their progression. We also highlight cellular and subcellular mechanisms of ageing with a focus on protein thiol oxidation and posttranslational modifications that impact cellular homeostasis and the advent and progression of ageing-related cancers. By having a better understanding of the mechanisms of ageing, we can hopefully develop effective, safe, and efficient therapeutic modalities that can be used prophylactically and/or concurrent to the onset of ageing.

Efficacy of different 8 h time-restricted eating schedules on visceral adipose tissue and cardiometabolic health: A study protocol

BACKGROUND AND AIMS

To investigate the efficacy and feasibility of three different 8 h time-restricted eating (TRE) schedules (i.e., early, late, and self-selected) compared to each other and to a usual-care (UC) intervention on visceral adipose tissue (VAT) and cardiometabolic health in men and women.

METHODS AND RESULTS

Anticipated 208 adults (50% women) aged 30-60 years, with overweight/obesity (25 ≤ BMI<40 kg/m2) and with mild metabolic impairments will be recruited for this parallel-group, multicenter randomized controlled trial. Participants will be randomly allocated (1:1:1:1) to one of four groups for 12 weeks: UC, early TRE, late TRE or self-selected TRE. The UC group will maintain their habitual eating window and receive, as well as the TRE groups, healthy lifestyle education for weight management. The early TRE group will start eating not later than 10:00, and the late TRE group not before 13:00. The self-selected TRE group will select an 8 h eating window before the intervention and maintain it over the intervention. The primary outcome is changes in VAT, whereas secondary outcomes include body composition and cardiometabolic risk factors.

CONCLUSION

This study will determine whether the timing of the eating window during TRE impacts its efficacy on VAT, body composition and cardiometabolic risk factors and provide insights about its feasibility.

Household food security, child dietary diversity and coping strategies among rural households. The case of Kole District in northern Uganda

Household food security, feeding practices, dietary diversity and coping strategies to household food insecurity are largely interconnected. Using a cross sectional study approach involving 162 mothers and care givers of children 0-36 months of age in Kole district of northern Uganda, this study examined the household food security status, child dietary diversity and household coping strategies. The study revealed that a slight majority of the households (55%) were food secure although with a low level of child dietary diversity experienced (68.1% for children 6-23 months age group and 55.3% for 24-36 months age group). We found that starch-based foods derived from cereals, roots and tubers were the most predominantly used food group in child feeding (82%), with limited consumption of other essential food groups, notably fruits, vegetables, meats and dairy products (18% combined). Additionally, only 57% of children 0 to 6 months old were receiving exclusive breastfeeding, and the introduction of complementary foods is often delayed and not well planned for those above 6 months of age. Results also showed that a wide range of coping strategies are employed however the major ones were, reliance on less preferred food (54.9%), limiting portions of meals (35.2%), reducing number of meals taken in a day (29%), and gathering wild fruits and harvesting immature crops (29.6%). It was observed that household food security is a strong determinant of child dietary diversity, may influence feeding practices and the range of coping strategies applicable to households when they experience food insecurity. Furthermore, nutritional education, household size and livelihood diversity play a significant role in determining household food security status, child dietary diversity and coping with food insecurity within rural households. In conclusion, addressing household food security, and coping strategies can play an important role in improving child feeding practices and dietary diversity in rural communities.

Calorie restriction modulates the transcription of genes related to stress response and longevity in human muscle: The CALERIE study

The lifespan extension induced by 40% caloric restriction (CR) in rodents is accompanied by postponement of disease, preservation of function, and increased stress resistance. Whether CR elicits the same physiological and molecular responses in humans remains mostly unexplored. In the CALERIE study, 12% CR for 2 years in healthy humans induced minor losses of muscle mass (leg lean mass) without changes of muscle strength, but mechanisms for muscle quality preservation remained unclear. We performed high-depth RNA-Seq (387-618 million paired reads) on human vastus lateralis muscle biopsies collected from the CALERIE participants at baseline, 12- and 24-month follow-up from the 90 CALERIE participants randomized to CR and "ad libitum" control. Using linear mixed effect model, we identified protein-coding genes and splicing variants whose expression was significantly changed in the CR group compared to controls, including genes related to proteostasis, circadian rhythm regulation, DNA repair, mitochondrial biogenesis, mRNA processing/splicing, FOXO3 metabolism, apoptosis, and inflammation. Changes in some of these biological pathways mediated part of the positive effect of CR on muscle quality. Differentially expressed splicing variants were associated with change in pathways shown to be affected by CR in model organisms. Two years of sustained CR in humans positively affected skeletal muscle quality, and impacted gene expression and splicing profiles of biological pathways affected by CR in model organisms, suggesting that attainable levels of CR in a lifestyle intervention can benefit muscle health in humans.

Causal relationship between breakfast skipping and bone mineral density: a two-sample Mendelian randomized study

Objective

To explore the causal association between breakfast skipping and bone mineral density (BMD) through two-sample Mendelian randomisation (MR) analysis.

Methods

A two-sample MR approach was adopted to explore the causal relationship of breakfast skipping with BMDs (across three skeletal sites and five age groups). Publicly available genome-wide association study summary data were used for MR analysis. We used five methods to estimate the causal associations between breakfast skipping and BMDs: inverse-variance weighting (IVW), MR-Egger, weighted median, simple mode, and weighted mode. IVW was used for the main analysis and the remaining four methods were used as supplementary analyses. The heterogeneity of the MR results was determined using IVW and MR-Egger methods. The pleiotropy of the MR results was determined using MR-Egger intercept. Furthermore, a leave-one-out test was performed to determine whether the MR results were affected by a single nucleotide polymorphism.

Results

With the IVW method, we did not find any causal relationship between breakfast skipping and forearm, femoral neck, and lumbar spine BMD. Subsequently, when we included BMD data stratified by five different age groups in the analysis, the results showed that there was no apparent causal effect between breakfast skipping and age-stratified BMD. This finding was supported by all four supplementary methods (P > 0.05 for all methods). No heterogeneity or horizontal pleiotropy was detected in any of the analyses (P > 0.05). The leave-one-out tests conducted in the analyses did not identify any single nucleotide polymorphism that could have influenced the MR results, indicating the reliability of our findings.

Conclusion

No causal effect was found between breakfast skipping and BMD (across three skeletal sites and five age groups).