Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial

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.

Intermittent Fasting-Improved Glucose Homeostasis Is Not Entirely Dependent on Caloric Restriction in db/db Male Mice

Intermittent fasting (IF), which involves prolonged fasting intervals accompanied by caloric restriction (CR), is an effective dietary treatment for obesity and diabetes. Although IF offers many benefits, it is difficult to determine whether these benefits are the consequences of CR. Every-other-day feeding (EODF) is a commonly used IF research model. This study was designed to identify factors, in addition to CR, responsible for the effects of EODF and the possible underlying mechanisms. Diabetic db/db mice were divided into three groups: ad libitum (AL), meal feeding (MF), and EODF. The MF model was used to attain a level of CR comparable to that of EODF, with food distribution evenly divided between 10:00 a.m. and 6:00 p.m., thereby minimizing the fasting interval. EODF yielded greater improvements in glucose homeostasis than MF in db/db mice by reducing fasting glucose levels and enhancing glucose tolerance. However, these effects on glucose metabolism were less pronounced in lean mice. Furthermore, ubiquitination of the liver-specific glucocorticoid (GC) receptor (GR) facilitated its degradation and downregulation of Kruppel-like factor 9 (KLF9), which ultimately suppressed liver gluconeogenesis in diabetic EODF mice. Although GR and KLF9 might mediate the metabolic benefits of EODF, the potential benefits of EODF might be limited by elevated serum GC levels in diabetic EODF mice. Overall, this study suggests that the metabolic benefits of EODF in improving glucose homeostasis are independent of CR, possibly because of the downstream effects of liver-specific GR degradation.

ARTICLE HIGHLIGHTS

The effectiveness of mobile app usage in facilitating weight loss: An observational study

Aim

With increasing rates of global obesity and associated health issues, there is an ever-increasing need for weight management solutions to be more accessible. Mobile applications offer accessible support systems and have the potential to offer a viable and effective weight management solution as an alternative to traditional healthcare models.

Objective

To evaluate the effectiveness of the SIMPLE mobile application for time-restricted eating in achieving weight loss (WL).

Methods

User data were analyzed between January 2021 and January 2023. In-app activity was calculated as the proportion of active days over 12, 26 and 52 weeks. A day is considered active if it contains at least one in-app action (e.g., logging weight, food, fasting, or physical activity). Users were categorized into four in-app activity levels: inactive (in-app activity <33%), medium activity (33%-66%), high activity (66%-99%), and maximal activity (100%). Weight change among in-app activity groups was assessed at 12, 26, and 52 weeks.

Results

Out of 53,482 users, a positive association was found between the use of the SIMPLE app and WL. Active app users lost more weight than their less active counterparts. Active users had a median WL of 4.20%, 5.04%, and 3.86% at 12, 26, and 52 weeks, respectively. A larger percentage of active users-up to 50.26%-achieved clinically significant WL (≥5%) when compared to inactive users. A dose-response relationship between WL and app usage was found after adjusting for gender, age, and initial Body Mass Index; a 10% increase in app activity correlated with increased WL by 0.43, 0.66 and 0.69 kg at 12, 26, and 52 weeks, respectively.

Conclusions

The study demonstrates that the SIMPLE app enables effective WL directly associated with the level of app engagement. Mobile health applications offer an accessible and effective weight management solution and should be considered when supporting adults to lose weight.

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.

Intermittent fasting as a dietary intervention with potential sexually dimorphic health benefits

Intermittent fasting (IF) has proven to be a feasible dietary intervention for the wider population. The recent increase in IF clinical trials highlights its potential effects on health, including changes in body composition, cardiometabolic status, and aging. Although IF may have clinical applications in different populations, studies suggest there may be sex-specific responses in parameters such as body composition or glucose and lipid metabolism. Here, the existing literature on IF clinical trials is summarized, the application of IF in both disease prevention and management is discussed, and potential disparities in response to this type of diet between men and women are assessed. Moreover, the potential mechanisms that may be contributing to the sexually dimorphic response, such as age, body composition, tissue distribution, or sex hormones are investigated. This review underscores the need to further study these sex-specific responses to IF to define the most effective time frames and length of fasting periods for men and women. Tailoring IF to specific populations with a personalized approach may help achieve its full potential as a lifestyle intervention with clinical benefits.

Methionine as a regulator of bone remodeling with fasting

Caloric restriction improves metabolic health but is often complicated by bone loss. We studied bone parameters in humans during a 10-day fast and identified candidate metabolic regulators of bone turnover. Pro-collagen 1 intact N-terminal pro-peptide (P1NP), a bone formation marker, decreased within 3 days of fasting. Whereas dual-energy x-ray absorptiometry measures of bone mineral density were unchanged after 10 days of fasting, high-resolution peripheral quantitative CT demonstrated remodeling of bone microarchitecture. Pathway analysis of longitudinal metabolomics data identified one-carbon metabolism as fasting dependent. In cultured osteoblasts, we tested the functional significance of one-carbon metabolites modulated by fasting, finding that methionine - which surged after 3 days of fasting - affected markers of osteoblast cell state in a concentration-dependent manner, in some instances exhibiting a U-shaped response with both low and high concentrations driving putative antibone responses. Administration of methionine to mice for 5 days recapitulated some fasting effects on bone, including a reduction in serum P1NP. In conclusion, a 10-day fast in humans led to remodeling of bone microarchitecture, potentially mediated by a surge in circulating methionine. These data support an emerging model that points to a window of optimal methionine exposure for bone health.

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.

A Narrative Review of the Significance of Popular Diets in Diabetes Mellitus Management

Diabetes mellitus is a collection of metabolic disorders marked by elevated levels of glucose in the blood due to irregularities in the generation or functioning of insulin. Medical nutrition therapy and weight loss are crucial elements in the management of diabetes and the prevention of complications. Several diets have become popular over time for the goal of achieving weight loss, but their popularity has declined due to a lack of reliable scientific evidence. This study classifies popular diets into three categories: diets that manage the composition of macronutrients, diets that restrict specific foods or food groups, and diets that manipulate meal timing. The review includes research studies that investigated the effects of popular diets on the prevention, management, and complications of diabetes. It is clear that different popular diets can have positive effects on both preventing and treating diabetes and preventing and treating complications related to diabetes. However, it is not practical to determine which diet is the most effective option for preventing or controlling diabetes. Thus, the main focus should be on common underlying factors that support well-being, such as decreasing the intake of refined grains and added sugar, choosing non-starchy vegetables, and giving priority to whole foods over processed foods whenever possible, until there is stronger evidence supporting the specific benefits of different dietary patterns.

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.

Antiobesity pharmacotherapy to facilitate living kidney donation

Obesity is a chronic, relapsing disease that increases the risks of living kidney donation; at the same time, transplant centers have liberalized body mass index constraints for donors. With the increasing number of antiobesity medications available, the treatment of obesity with antiobesity medications may increase the pool of potential donors and enhance donor safety. Antiobesity medications are intended for long-term use given the chronic nature of obesity. Cessation of treatment can be expected to lead to weight regain and increase the risk of comorbidity rebound/development. In addition, antiobesity medications are meant to be used in conjunction with-rather than in replacement of-diet and physical activity optimization. Antiobesity medication management includes selecting medications that may ameliorate any coexisting medical conditions, avoiding those that are contraindicated in such conditions, and being sensitive to any out-of-pocket expenses that may be incurred by the potential donor. A number of questions remain regarding who will and should shoulder the costs of long-term obesity treatment for donors. In addition, future studies are needed to quantify the degree of weight loss and duration of weight loss maintenance needed to normalize the risk of adverse kidney outcomes relative to comparable nondonors and lower-weight donors.

Impact of fasting on the AMPK and PGC-1α axis in rodent and human skeletal muscle: A systematic review

Based primarily on evidence from rodent models fasting is currently believed to improve metabolic health via activation of the AMPK-PGC-1α axis in skeletal muscle. However, it is unclear whether the skeletal muscle AMPK-PGC-1α axis is activated by fasting in humans. The current systematic review examined the fasting response in skeletal muscle from 34 selected studies (7 human, 21 mouse, and 6 rat). From these studies, we gathered 38 unique data points related to AMPK and 47 related to PGC-1α. In human studies, fasting mediated activation of the AMPK-PGC-1α axis is largely absent. Although evidence does support fasting-induced activation of the AMPK-PGC-1α axis in rodent skeletal muscle, the evidence is less robust than anticipated. Our findings question the ability of fasting to activate the AMPK-PGC-1α axis in human skeletal muscle and suggest that the metabolic benefits of fasting in humans are associated with caloric restriction rather than the induction of mitochondrial biogenesis. Registration: https://doi.org/10.17605/OSF.IO/KWNQY.

Comparative efficacy of energy-restricted dietary interventions in overweight and obese populations: A systematic review and network meta-analysis

This meta-analysis compared the effectiveness of different energy-restricted diets on body composition, glucose metabolism, and lipid metabolism in overweight and obese populations. Five databases were searched to identify relevant studies in English from inception until July 20, 2023, for randomized controlled trials of at least 2 weeks duration assessing the effects of continuous energy-restricted diets compared with any intermittent energy-restricted diet in obesity adults. The risk of bias was assessed using the Cochrane Risk of Bias Tool version 2.0, while the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system was used to assess the certainty of the evidence. A non-informative prior distribution Bayesian network meta-analysis was conducted. Thirty-eight studies (3039 participants) assessing four energy-restricted diets were included. Three RCTs were at high risk of bias with a very low to moderate certainty of evidence. Combined with pairwise comparisons and surface under the cumulative ranking curve, alternate-day fasting may be the best energy restriction regimen with the potential to have the most beneficial effects on various aspects of the obesity population. More rigorously designed and long-term follow-up studies are warranted.

Comparison of three methods of intermittent fasting in high-fat-diet-induced obese mice

Purpose

Intermittent fasting (IF), describes a variety of diets that the individual is exposed to intermittent periods of fasting and refeeding. The present study was designed to compare the three most popular intermittent fasting methods in high-fat-diet-induced obese mice.

Methods

50 male C57BL/6 mice were divided into Normal Control (CN), High-Fat Control (CH), IF1 (Alternate Day Fasting), IF2 (Time-Restricted Feeding), IF3 (5:2 Diet) diets. In the first phase of the study, the mice were fed ad libitum either with a 54% Calorie high-fat (CH, IF1, IF2, IF3) or standard CHOW (CN) for 8 weeks. Then, in the intervention phase, the IF groups were fasted for four weeks based on their fasting protocol. At the end of the study, the mice fasting blood, liver and fat tissue samples were biochemically and pathologically assessed.

Results

The weight loss during the fasting period in IF1 and IF2 groups was significantly greater than CH. The epididymal fat pad weight was significantly lower in IF2 and IF3 compared to CH. The serum Triglyceride was significantly greater in CH than in the CN group. The tissue injury scores of the high-fat-diet groups were significantly greater than CN. Also, the tissue injury score was greater in IF1 group compared to the high-fat control group.

Conclusion

All of the fasting protocols can prompt acceptable energy restriction and the ADF and TRF protocols can significantly cause weight loss. Also, the TRF and 5:2 Diets can lower the visceral adiposity. However further human studies focusing on dietary adherence seem necessary.

[Intermittent fasting: effects in diverse clinical settings]

Introduction

Introduction: intermittent fasting plans propose to limit food intake during specific periods as nutritional therapeutic strategies to treat different metabolic conditions in various clinical entities. However, the heterogeneity between each context of intermittent fasting could generate different results in metabolic parameters. Objective: to evaluate the clinical application of intermittent fasting and to discern whether it offers advantages over other traditional strategies. Methods: structured questions were formulated (PICO), and the methodology followed the guidelines established by the PRISMA 2020 statement. The search was conducted in different databases (PubMed, Cochrane Library and Google Scholar). Results: we found 3,962 articles, of which 56 were finally included; 3,906 articles that did not directly or indirectly answer the structured questions were excluded. Conclusions: compared to conventional diets, the various AI schemes do not generate advantages or disadvantages in terms of weight loss and lipid profile, although in the alternate-day variant there are greater insulin reductions than those observed in the continuous energy restriction. The heterogeneity of the interventions, the populations studied, the comparators, the results, and the type of design make it impossible to extrapolate the effects found in all clinical scenarios and generalize the recommendations.

Risks and Benefits of Intermittent Fasting for the Aging Cardiovascular System

Population aging and the associated increase in cardiovascular disease rates pose serious threats to global public health. Different forms of fasting have become an increasingly attractive strategy to directly address aging and potentially limit or delay the onset of cardiovascular diseases. A growing number of experimental studies and clinical trials indicate that the amount and timing of food intake as well as the daily time window during which food is consumed, are crucial determinants of cardiovascular health. Indeed, intermittent fasting counteracts the molecular hallmarks of cardiovascular aging and promotes different aspects of cardiometabolic health, including blood pressure and glycemic control, as well as body weight reduction. In this report, we summarize current evidence from randomized clinical trials of intermittent fasting on body weight and composition as well as cardiovascular and metabolic risk factors. Moreover, we critically discuss the preventive and therapeutic potential of intermittent fasting, but also possible detrimental effects in the context of cardiovascular aging and related disease. We delve into the physiological mechanisms through which intermittent fasting might improve cardiovascular health, and raise important factors to consider in the design of clinical trials on the efficacy of intermittent fasting to reduce major adverse cardiovascular events among aged individuals at high risk of cardiovascular disease. We conclude that despite growing evidence and interest among the lay and scientific communities in the cardiovascular health-improving effects of intermittent fasting, further research efforts and appropriate caution are warranted before broadly implementing intermittent fasting regimens, especially in elderly persons.

The effect of time of eating on cardiometabolic risk in primary and secondary prevention of cardiovascular disease

Continuous energy restriction is currently considered the first-line dietary therapy for weight loss in individuals with obesity. Recently, interventions which alter the eating window and time of eating occasions have been explored as means to achieve weight loss and other cardiometabolic improvements such as a reduction in blood pressure, glycaemia, lipids and inflammation. It is unknown, however, whether these changes result from unintentional energy restriction or from other mechanisms such as the alignment of nutrient intake with the internal circadian clock. Even less is known regarding the safety and efficacy of these interventions in individuals with established chronic noncommunicable disease states, such as cardiovascular disease. This review examines the effects of interventions which alter both eating window and time of eating occasions on weight and other cardiometabolic risk factors in both healthy participants and those with established cardiovascular disease. We then summarise the state of existing knowledge and explore future directions of study.

Common and divergent molecular mechanisms of fasting and ketogenic diets

Intermittent short-term fasting (ISTF) and ketogenic diets (KDs) exert overlapping but not identical effects on cell metabolism, function, and resilience. Whereas health benefits of KD are largely mediated by the ketone bodies (KBs), ISTF engages additional adaptive physiological responses. KDs act mainly through inhibition of histone deacetylases (HDACs), reduction of oxidative stress, improvement of mitochondria efficiency, and control of inflammation. Mechanisms of action of ISTF include stimulation of autophagy, increased insulin and leptin sensitivity, activation of AMP-activated protein kinase (AMPK), inhibition of the mechanistic target of rapamycin (mTOR) pathway, bolstering mitochondrial resilience, and suppression of oxidative stress and inflammation. Frequent switching between ketogenic and nonketogenic states may optimize health by increasing stress resistance, while also enhancing cell plasticity and functionality.

Promotion of Successful Weight Management in Overweight and Obese Veterans (POWER-VET): Trial Design and Methods

BACKGROUND

Almost 75% of US adults are overweight or obese. Though intentional weight loss of as little as 3% improves physical functioning and reduces cardiometabolic risk, most adults are unsuccessful at long-term weight maintenance. Our hypothesis is that intermittent fasting (IF: short periods of intense energy restriction) will reduce weight regain. IF may combat obesity due to its effects on nutrient-sensing signaling pathways and circadian rhythm. The objective of this randomized clinical trial is to test the effectiveness of an intensive body weight management program with and without IF.

METHODS

In the Promotion of Successful Weight Management in Overweight and Obese Veterans (POWER-VET) trial (NCT04131647), 154 middle-aged and older adults (50-75 years) who are overweight and obese (BMI: 25-40 kg/m2) and seen at either a Baltimore, MD or San Antonio, TX Veterans Affairs Medical Center will be enrolled. Participants will undergo 12 weeks of weight loss (including a low-calorie heart healthy (HH) diet and exercise). Following weight loss, participants will be randomly assigned to one of two 24-week weight maintenance (WM) interventions: WM alone (continuation of HH diet and exercise) or WM + IF. The primary aim is to determine the effect of WM + IF compared to WM alone on body weight maintenance after intentional weight loss.

DISCUSSION

Determining effective, translatable strategies that minimize weight regain following successful weight loss holds public health relevance. This POWER-VET trial introduces an innovative practice of IF to prevent weight regain after clinically significant weight reduction and could provide evidence-based recommendations to promote this type of intervention in middle aged and older adults.

Various types of fasting diet and possible benefits in nonalcoholic fatty liver: Mechanism of actions and literature update

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury, affecting around one-fourth of the general population across the world. Several important pathophysiological mechanisms underlying NAFLD include oxidative stress, inflammation, liver fibrosis, and apoptosis. Currently, therapeutic approaches are not ideal for managing NAFLD, thus new approaches and treatments are still needed. Over the last two decades, various fasting protocols have been explored to reduce body weight and improve metabolic disorders. In this review, we provide updated literature that supports fasting regimens for subjects with NAFLD and describes underlying mechanisms of action. We suggest that fasting regimens may modulate NAFLD via several mechanisms, including changes in gut microbiota, hepatic arginase, hepatic autophagy, inflammatory responses, liver functional enzymes and hepatic steatosis, fibroblast growth factors signaling, white adipose tissue browning, adipokines, circadian rhythms, lipid profiles, and body composition.

Adaptive metabolic response to short-term intensive fasting

BACKGROUND & AIMS

Short-term intensive fasting (STIF), known as beego in Chinese phonetic articulation, has been practiced for more than two thousand years. However, the potential risk of STIF and the body's response to the risk have not been adequately evaluated. This study aims to address this issue, focusing on the STIF-triggered metabolic response of the liver and kidney.

METHODS

The STIF procedure in the clinical trial includes a 7-day water-only intensive fasting phase and a 7-day gradual refeeding phase followed by a regular diet. The intensive fasting in humans was assisted with psychological induction. To gain insights not available in the clinical trial, we designed a STIF program for mice that resulted in similar phenotypes seen in humans. Plasma metabolic profiling and examination of gene expression as well as liver and kidney function were performed by omics, molecular, biochemical and flow cytometric analyses. A human cell line model was also used for mechanistic study.

RESULTS

Clinically significant metabolites of fat and protein were found to accumulate during the fasting phase, but they were relieved after gradual refeeding. Metabolomics profiling revealed a universal pattern in the consumption of metabolic intermediates, in which pyruvate and succinate are the two key metabolites during STIF. In the STIF mouse model, the accumulation of metabolites was mostly counteracted by the upregulation of catabolic enzymes in the liver, which was validated in a human cell model. Kidney filtration function was partially affected by STIF but could be recovered by refeeding. STIF also reduced oxidative and inflammatory levels in the liver and kidney. Moreover, STIF improved lipid metabolism in mice with fatty liver without causing accumulation of metabolites after STIF.

CONCLUSIONS

The accumulation of metabolites induced by STIF can be relieved by spontaneous upregulation of catabolic enzymes, suggesting an adaptive and protective metabolic response to STIF stress in the mammalian body.

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.

Impact of Intermittent Fasting and/or Caloric Restriction on Aging-Related Outcomes in Adults: A Scoping Review of Randomized Controlled Trials

Intermittent fasting (IF) and caloric restriction (CR) are dietary strategies to prevent and attenuate obesity associated with conditions and aging-related outcomes. This scoping review examined the cardiometabolic, cancer, and neurocognitive outcome differences between IF and CR interventions among adults. We applied a systematic approach to scope published randomized controlled trials (databases: PubMed, CINAHL Plus, PsychInfo, Scopus, and Google Scholar) from inception through August 2023. The initial search provided 389 unique articles which were critically appraised. Thirty articles met the eligibility criteria for inclusion: 12 were IF, 10 were CR, and 8 were combined IF and CR interventions. IF and CR were associated with weight loss; however, IF studies tended to report greater adherence compared with CR. Overall, IF and CR were equivalently effective across cardiometabolic, cancer, and neurocognitive outcomes. Our findings suggest that IF has health benefits in a variety of conditions and may be better accepted and tolerated than CR, but more comparative research is required.

InterVFast-effectiveness and acceptance of intermittent fasting in cardiac rehabilitation patients: study protocol of a randomized controlled trial

BACKGROUND

Research on intermittent fasting has shown that it can improve a variety of health outcomes, including blood sugar control, blood lipid levels and blood pressure. Only few studies document longer periods of fasting, especially in rehabilitation participants. Cardiac inpatient rehabilitation follows a multidisciplinary approach including change of health behaviour to reduce patients' risk of future cardiovascular events. To date, evidence suggests that intermittent fasting can be an effective way to improve health and well-being, but more research is needed to fully understand its long-term effects and factors that promote the implementation. Therefore, the aim of the ongoing InterVFast trial is to investigate the effectiveness of intermittent fasting amongst cardiac rehabilitation patients after 4-week inpatient rehabilitation as well as 3 and 12 months subsequently including patients' perspective.

METHODS

This single-centre randomized controlled trial evaluates the effectiveness of the InterVFast intervention in weight loss (primary outcome). We also examine patients' acceptance and the effect on relevant outcomes as blood glucose and triglyceride levels, cholesterol and high-sensitivity C-reactive protein. Weight, blood samples and clinical data are collected as part of the initial and final examination during inpatient rehabilitation. During inpatient rehabilitation, participants daily note fasting intervals and meals eaten as well as practicability in a fasting diary. In addition, interviews about perceived advantages and disadvantages and acceptance are carried out with the participants in the IG. A standardized follow-up examination (weight, blood samples) will be carried out by the family doctor after 3 and 12 months (t2 and t3).

DISCUSSION

Compared to other weight-loss intervention studies, our study addresses patients with coronary heart disease and includes patients' acceptance as well as long-term maintenance. It is hypothesized that participation in the InterVfast intervention will improve relevant health outcomes in a sample of cardiac rehabilitation patients and thus constitute a behavioural prevention strategy to reduce the risk of future cardiac events and improve overall health and quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov DRKS00023983. Registered on February 17, 2022.

Network meta-analysis of three different forms of intermittent energy restrictions for overweight or obese adults

This network meta-analysis aimed to compare the efficacy of three forms of intermittent energy restriction (IER), including alternate-day fasting (ADF), the 5:2 diet, and time-restricted feeding (TRF), in overweight or obese adults. A literature search was conducted in PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) to find relevant randomized controlled trials (RCTs) until August 10, 2022. The modified Cochrane risk of bias assessment tool was applied to assess the methodological quality of eligible studies. Random network meta-analysis was conducted using STATA 14.0. Sixteen RCTs were included, with 1228 patients. Overall, the methodological quality ranged from low to moderate. ADF was superior to CER and 5:2 diet in reducing waist circumference, whereas 5:2 diet was superior to CER in reducing BMI. Regarding fat mass and drop-out, all forms of IER were comparable. Sensitivity analyses indicated that the type of individuals had no influence on the pooled results; nevertheless, ADF significantly reduced weight compared to CER and achieved significant waist circumference reduction compared to CER, 5:2 diet, and TRF. ADF may be preferentially prescribed for overweight or obese adults. More large-scale and high-quality studies are required, however, to investigate the effect of TRF on overweight and obesity.

5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

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

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

Oxidative damage in neurodegeneration: roles in the pathogenesis and progression of Alzheimer disease

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.

Effects of Intermittent Energy Restriction Compared with Those of Continuous Energy Restriction on Body Composition and Cardiometabolic Risk Markers - A Systematic Review and Meta-Analysis of Randomized Controlled Trials in Adults

The interest in intermittent energy restriction (IER) diets as a weight-loss approach is increasing. Different IER protocols exist, including time-restricted eating (TRE), alternate-day fasting (ADF), and the 5:2 diet. This meta-analysis compared the effects of these IER diets with continuous energy restriction (CER) on anthropometrics and cardiometabolic risk markers in healthy adults. Twenty-eight trials were identified that studied TRE (k = 7), ADF (k = 10), or the 5:2 diet (k = 11) for 2-52 wk. Energy intakes between intervention groups within a study were comparable (17 trials), lower in IER (5 trials), or not reported (6 trials). Weighted mean differences (WMDs) were calculated using fixed- or random-effects models. Changes in body weight [WMD: -0.42 kg; 95% confidence interval (CI): -0.96 to 0.13; P = 0.132] and fat mass (FM) (WMD: -0.31 kg; 95% CI: -0.98 to 0.36; P = 0.362) were comparable when results of the 3 IER diets were combined and compared with those of CER. All IER diets combined reduced fat-free mass (WMD: -0.20 kg; 95% CI: -0.39 to -0.01; P = 0.044) and waist circumference (WMD: -0.91 cm; 95% CI: -1.76 to -0.06; P = 0.036) more than CER. Effects on body mass index [BMI (kg/m2)], glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), serum lipid and lipoprotein concentrations, and blood pressure did not differ. Further, TRE reduced body weight, FM, and fat-free mass more than CER, whereas ADF improved HOMA-IR more. BMI was reduced less in the 5:2 diet compared with CER. In conclusion, the 3 IER diets combined did not lead to superior improvements in anthropometrics and cardiometabolic risk markers compared with CER diets. Slightly greater reductions were, however, observed in fat-free mass and waist circumference. To what extent differences in energy intakes between groups within studies may have influenced these outcomes should be addressed in future studies.

The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans

The belief that the anabolic response to feeding during postexercise recovery is transient and has an upper limit and that excess amino acids are being oxidized lacks scientific proof. Using a comprehensive quadruple isotope tracer feeding-infusion approach, we show that the ingestion of 100 g protein results in a greater and more prolonged (>12 h) anabolic response when compared to the ingestion of 25 g protein. We demonstrate a dose-response increase in dietary-protein-derived plasma amino acid availability and subsequent incorporation into muscle protein. Ingestion of a large bolus of protein further increases whole-body protein net balance, mixed-muscle, myofibrillar, muscle connective, and plasma protein synthesis rates. Protein ingestion has a negligible impact on whole-body protein breakdown rates or amino acid oxidation rates. These findings demonstrate that the magnitude and duration of the anabolic response to protein ingestion is not restricted and has previously been underestimated in vivo in humans.

Take metabolic heterogeneity into consideration when applying dietary interventions to cancer therapy: A review

In recent years, dietary interventions have attracted much attention in cancer therapy. Mechanistic studies suggest that dietary interventions can inhibit the progression of cancer through deprivation of essential metabolites, lowering the levels of protumor hormones, activation of anticancer immunity and synergistic effects with conventional anticancer therapies. The feasibility, safety and promising tumor outcomes have also been established in humans. However, the results from both preclinical and clinical studies are inconsistent or even conflicting, the reasons for which have not been extensively considered. In this review, we discuss the various heterogeneity, including dietary protocols, tissue of origin and cancer locations, spatial and temporal metabolic heterogeneity, and divergent combination treatment, that may affect the responses of different cancers to dietary interventions. Understanding this heterogeneity and taking them into consideration when applying dietary interventions to cancer therapy will allow us to deliver the right diet to the right patient at the right time to maximize compliance, safety and efficacy of conventional anticancer therapy and to improve the outcomes of patients with cancer.

Intermittent fasting and changes in clinical risk scores: Secondary analysis of a randomized controlled trial

Background

Intermittent fasting may increase longevity and lower cardiometabolic risk. This study evaluated whether fasting modifies clinical risk scores for mortality [i.e., Intermountain Mortality Risk Score (IMRS)] or chronic diseases [e.g., Pooled Cohort Risk Equations (PCRE), Intermountain Chronic Disease score (ICHRON)].

Methods and results

Subjects (N = 71) completing the WONDERFUL trial were aged 21-70 years, had ≥1 metabolic syndrome criteria, elevated cholesterol, and no anti-diabetes medications, statins, or chronic diseases. The intermittent fasting arm underwent 24-h water-only fasting twice-per-week for 4 weeks and once-per-week for 22 weeks (26 weeks total). Analyses examined the IMRS change score at 26 weeks vs. baseline between intermittent fasting (n = 38) and ad libitum controls (n = 33), and change scores for PCRE, ICHRON, HOMA-IR, and a metabolic syndrome score (MSS). Age averaged 49 years; 65% were female. Intermittent fasting increased IMRS (0.78 ± 2.14 vs. controls: -0.61 ± 2.56; p = 0.010) but interacted with baseline IMRS (p-interaction = 0.010) to reduce HOMA-IR (but not MSS) more in subjects with higher baseline IMRS (median HOMA-IR change: fasters, -0.95; controls, +0.05) vs. lower baseline IMRS (-0.29 vs. -0.32, respectively). Intermittent fasting reduced ICHRON (-0.92 ± 2.96 vs. 0.58 ± 3.07; p = 0.035) and tended to reduce PCRE (-0.20 ± 0.22 vs. -0.14 ± 0.21; p = 0.054).

Conclusions

Intermittent fasting increased 1-year IMRS mortality risk, but decreased 10-year chronic disease risk (PCRE and ICHRON). It also reduced HOMA-IR more in subjects with higher baseline IMRS. Increased IMRS suggests fasting may elevate short-term mortality risk as a central trigger for myriad physiological responses that elicit long-term health improvements. Increased IMRS may also reveal short-term fasting-induced safety concerns.

Non-invasive omics analysis delineates molecular changes in water-only fasting and its sex-discriminating features in metabolic syndrome patients

Fasting has been grown in popularity with multiple potential benefits. However, very few studies dynamically monitor physiological and pathological changes during long-term fasting using noninvasive methods. In the present study, we recruited 37 individuals with metabolic syndrome to engage in a 5-day water-only fasting regimen, and simultaneously captured the molecular alterations through urinary proteomics and metabolomics. Our findings reveal that water-only fasting significantly mitigated metabolic syndrome-related risk markers, such as body weight, body mass index, abdominal circumference, blood pressure, and fasting blood glucose levels in metabolic syndrome patients. Indicators of liver and renal function remained within the normal range, with the exception of uric acid. Notably, inflammatory response was inhibited during the water-only fasting period, as evidenced by a decrease in the human monocyte differentiation antigen CD14. Intriguingly, glycolysis, tricarboxylic acid cycle, and oxidative phosphorylation underwent a sex-dependent reprogramming throughout the fasting period, whereby males exhibited a greater upregulation of carbohydrate metabolism-related enzymes than females. This disparity may be attributed to evolutionary pressures. Collectively, our study sheds light on the beneficial physiological effects and novel dynamic molecular features associated with fasting in individuals with metabolic syndrome using noninvasive methods.

The impact of prolonged fasting on 24h energy metabolism and its 24h rhythmicity in healthy, lean males: A randomized cross-over trial

OBJECTIVE

Human energy expenditure and substrate oxidation are under circadian control and food intake is a time cue for the human biological clock, leading to 24h feeding-fasting cycles in energy and substrate metabolism. In recent years, (intermittent) fasting protocols have also become popular to improve metabolic health. Here, we aimed to investigate the impact of food intake on the 24h patterns of energy metabolism as well as to provide data on the timeline of changes in energy metabolism that occur upon an extended period of fasting.

RESEARCH DESIGN AND METHODS

In a randomized, cross-over design, twelve healthy males underwent a 60h fast which was compared to a 60h fed condition. In the fed condition meals were provided at energy balance throughout the study. Conditions were separated by a two week period of habitual diet. Volunteers resided in a respiration chamber for the entire 60h to measure energy expenditure and substrate oxidation hour by hour. Volunteers performed a standardized activity protocol while in the chamber. Blood samples were drawn after 12, 36 and 60h.

RESULTS

Immediately following the breakfast meal (in the fed condition), fat oxidation became higher in the fasted condition compared to the fed condition and remained elevated throughout the study period. The initial rapid increase in fat oxidation corresponded with a decline in the hepatokine activin A (r = -0.86, p = 0.001). The contribution of fat oxidation to total energy expenditure gradually increased with extended abstinence from food, peaking after 51h of fasting at 160 mg/min. Carbohydrate oxidation stabilized at a low level during the second day of fasting and averaged around 60 mg/min with only modest elevations in response to physical activity. Although 24h energy expenditure was significantly lower with prolonged fasting (11.0 ± 0.4 vs 9.8 ± 0.2 and 10.9 ± 0.3 vs 10.3 ± 0.3 MJ in fed vs fasting, day 2 and 3 respectively, p < 0.01), the 24h fluctuations in energy expenditure were comparable between the fasted and fed condition. The fluctuations in substrate oxidation were, however, significantly (p < 0.001 for both carbohydrate and fat oxidation) altered in the fasted state, favouring fat oxidation.

CONCLUSIONS

Energy expenditure displays a day-night rhythm, which is independent of food intake. In contrast, the day-night rhythm of both carbohydrate and fat oxidation is mainly driven by food intake. Upon extended fasting, the absolute rate of fat oxidation rapidly increases and keeps increasing during a 60h fast, whereas carbohydrate oxidation becomes progressively diminished.

TRIAL REGISTRATION

www.trialregister.nl NTR 2042.

Eating patterns contribute to shaping the gut microbiota in the mucosal simulator of the human intestinal microbial ecosystem

Eating patterns, i.e. meal frequency and circadian timing of meals, are often modified in weight loss and metabolic healing strategies. However, in-depth research into the effects on the gut microbiome remains scarce, particularly across various colon regions and niches. We identified eating patterns to contribute in shaping the in vitro gut biomass production, metabolism, and microbial community compositions by subjecting four faecal microbiomes to a pattern that is standardized for a dynamic gut model (feeding at 09, 17, and 01 h), a typical Western (breakfast, lunch, and dinner at 09, 13, and 19 h, respectively), and a time-restricted pattern (single meal at 09 h). While eating patterns moderately affected the microbiome (2.4% and 1.8% significant variation in proportional and quantitative microbial compositions, respectively), significant changes were noted in the time-restricted pattern, including increased Bacteroides, Butyricicoccus, Dialister, and Faecalibacterium abundances. Sampling every 4 h revealed no significant circadian fluctuations in biomass production, microbial community compositions, or functionality. Longer fasting times favoured the growth of slower-growing species, such as Akkermansia, Dialister, and Parasutterella over faster-growers, such as Pseudomonas and Stenotrophomonas. Our findings illustrate the importance of recording and considering eating patterns as a gut microbiome determinant in in vivo and in vitro dietary intervention studies.

Time-Restricted Eating and Its Metabolic Benefits

Newer management strategies are being evaluated to treat obesity, which continues to increase worldwide. After 12 h of fasting, the body switches from glucose to fat metabolism, regulating protein synthesis and autophagy. These cellular responses are central to the metabolic benefits of time-restricted eating (TRE), independent of calorie restriction and weight loss, and they have heightened interest in TRE regimens. Controversy remains, however, regarding the benefits of TRE regimens. We reviewed the current literature and concluded that TRE is equivalent to calorie restriction for weight loss and has positive effects for patients with diseases such as nonalcoholic fatty liver disease, cancer, and cardiovascular disease.

Weight Management Interventions Provided by a Dietitian for Adults with Overweight or Obesity: An Evidence Analysis Center Systematic Review and Meta-Analysis

BACKGROUND

Obesity is associated with a multitude of comorbidities and considerable health care costs.

OBJECTIVE

The objective of this review was to examine the efficacy of weight management interventions provided by a registered dietitian or international equivalent (referred to as "dietitian").

METHODS

This systematic review and meta-analysis of randomized controlled trials (RCTs) examined the effect of weight management interventions provided by a dietitian, compared with usual care or no intervention, on several cardiometabolic outcomes and quality of life in adults with overweight or obesity. MEDLINE, Embase, PsycINFO, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, and CINAHL databases were searched for eligible RCTs published between January 2008 and January 2021 in the English language. Meta-analyses were conducted using a random-effects model, publication bias was assessed using funnel plots and Egger's statistics, and heterogeneity was assessed by interpreting I2 values. Efficacy of intervention components, such as telehealth or group contacts, were explored in sub-group analyses. Version 2 of the risk-of-bias tool for RCTs was used to assess risk of bias. The Grading of Recommendations Assessment, Development and Evaluation method was used to determine certainty of evidence.

RESULTS

This systematic review included 62 RCTs. Compared with control conditions, weight management interventions provided by a dietitian resulted in improved body mass index (mean difference [MD] -1.5; 95% CI -1.74 to -1.26; moderate evidence certainty); percent weight loss (MD -4.01%; 95% CI -5.26% to -2.75%; high evidence certainty); waist circumference (MD -3.45 cm; 95% CI -4.39 to -2.51 cm; high evidence certainty); blood pressure (MD -3.04 mm Hg; 95% CI -5.10 to -0.98 mm Hg and MD -1.99 mm Hg; 95% CI -3.02 to -0.96 mm Hg for systolic blood pressure and diastolic blood pressure, respectively; moderate and low evidence certainty); and quality of life using the 36-Item Short Form Survey (MD 5.84; 95% CI 2.27 to 9.41 and 2.39; 95% CI 1.55 to 3.23 for physical and mental quality of life, respectively; low and moderate evidence certainty).

CONCLUSIONS

For adults with overweight or obesity, weight management interventions provided by a dietitian are efficacious for improving several examined cardiometabolic outcomes and quality of life.

The Nutriepigenome

Unlike genetic changes, epigenetics modulates gene expression without stable modification of the genome. Even though all cells, including sperm and egg, have an epigenome pattern, most of these modifications occur during lifetime and interestingly, some of them, are reversible. Lifestyle and especially nutrients as well as diet regimens are presently gaining importance due to their ability to affect the epigenome. On the other hand, since the epigenome profoundly affects gene expression profile it can be speculated that the epigenome could modulate individual response to nutrients. Recent years have thus seen growing interest on nutrients, macronutrients ratio and diet regimens capable to affect the epigenetic pattern. In fact, while genetic alterations are mostly detrimental at the individual level, reshaping the epigenome may be a feasible strategy to positively counteract the detrimental effect of aging. Here, I review nutrient consumption and diet regimens as a possible strategy to counteract aging-driven epigenome derangement.

Intermittent fasting in health and disease

CONTEXT

Intermittent fasting, a new-age dietary concept derived from an age-old tradition, involves repetitive cycles of fasting/calorie restriction and eating.

OBJECTIVE

We aim to take a deep dive into the biological responses to intermittent fasting, delineate the disease-modifying and cognitive effects of intermittent fasting, and also shed light on the possible side effects.

METHODS

Numerous in vitro and in vivo studies were reviewed, followed by an in-depth analysis, and compilation of their implications in health and disease.

RESULTS

Intermittent fasting improves the body's stress tolerance, which is further amplified with exercise. It impacts various pathological conditions like cancer, obesity, diabetes, cardiovascular disease, and neurodegenerative diseases.

CONCLUSION

During dietary restriction, the human body experiences a metabolic switch due to the depletion of liver glycogen, which promotes a shift towards utilising fatty acids and ketones in the system, thereby significantly impacting adiposity, ageing and the immune response to various diseases.

Intermittent fasting-the future treatment in NASH patients?

NASH is one of the leading causes of chronic liver disease with the potential of evolving towards end-stage liver disease and HCC, even in the absence of cirrhosis. Apart from becoming an increasingly prevalent indication for liver transplantation in cirrhotic and HCC patients, its burden on the healthcare system is also exerted by the increased number of noncirrhotic NASH patients. Intermittent fasting has recently gained more interest in the scientific community as a possible treatment approach for different components of metabolic syndrome. Basic science and clinical studies have shown that apart from inducing body weight loss, improving cardiometabolic parameters, namely blood pressure, cholesterol, and triglyceride levels; insulin and glucose metabolism; intermittent fasting can reduce inflammatory markers, endoplasmic reticulum stress, oxidative stress, autophagy, and endothelial dysfunction, as well as modulate gut microbiota. This review aims to further explore the main NASH pathogenetic metabolic drivers on which intermittent fasting can act upon and improve the prognosis of the disease, and summarize the current clinical evidence.

A phenotypic approach to obesity treatment

Obesity is a chronic disease that increases morbidity and mortality and adversely affects quality of life. The rapid rise of obesity has outpaced the development and deployment of effective therapeutic interventions, thereby creating a global health crisis. The presentation, complications, and response to obesity treatments vary, yet lifestyle modification, which is the foundational therapeutic intervention for obesity, is often "one size fits all." The concept of personalized medicine uses genetic and phenotypic information as a guide for disease prevention, diagnosis, and treatment and has been successfully applied in diseases such as cancer, but not in obesity. As we gain insight into the pathophysiologic mechanisms of obesity and its phenotypic expression, specific pathways can be targeted to yield a greater, more sustained therapeutic impact in an individual patient with obesity. A phenotype-based pharmacologic treatment approach utilizing objective measures to classify patients into predominant obesity mechanism groups resulted in greater weight loss (compared with a non-phenotype-based approach) in a recent study by Acosta and colleagues. In this review, we discuss the application of lifestyle modifications, behavior therapy and pharmacotherapy using the obesity phenotype-based approach as a framework.

A single 36-h water-only fast vastly remodels the plasma lipidome

Background

Prolonged fasting, characterized by restricting caloric intake for 24 h or more, has garnered attention as a nutritional approach to improve lifespan and support healthy aging. Previous research from our group showed that a single bout of 36-h water-only fasting in humans resulted in a distinct metabolomic signature in plasma and increased levels of bioactive metabolites, which improved macrophage function and lifespan in C. elegans.

Objective

This secondary outcome analysis aimed to investigate changes in the plasma lipidome associated with prolonged fasting and explore any potential links with markers of cardiometabolic health and aging.

Method

We conducted a controlled pilot study with 20 male and female participants (mean age, 27.5 ± 4.4 years; mean BMI, 24.3 ± 3.1 kg/m2) in four metabolic states: (1) overnight fasted (baseline), (2) 2-h postprandial fed state (fed), (3) 36-h fasted state (fasted), and (4) 2-h postprandial refed state 12 h after the 36-h fast (refed). Plasma lipidomic profiles were analyzed using liquid chromatography and electrospray ionization mass spectrometry.

Results

Several lipid classes, including lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylethanolamine, and triacylglycerol were significantly reduced in the 36-h fasted state, while free fatty acids, ceramides, and sphingomyelin were significantly increased compared to overnight fast and fed states (P < 0.05). After correction for multiple testing, 245 out of 832 lipid species were significantly altered in the fasted state compared to baseline (P < 0.05). Random forest models revealed that several lipid species, such as LPE(18:1), LPC(18:2), and FFA(20:1) were important features in discriminating the fasted state from both the overnight fasted and postprandial state.

Conclusion

Our findings indicate that prolonged fasting vastly remodels the plasma lipidome and markedly alters the concentrations of several lipid species, which may be sensitive biomarkers of prolonged fasting. These changes in lipid metabolism during prolonged fasting have important implications for the management of cardiometabolic health and healthy aging, and warrant further exploration and validation in larger cohorts and different population groups.

An alternative approach to obesity treatment: intermittent fasting

Overweight and obesity are an important public health problem that affects a significant part of the world population and increases the risk of many metabolic diseases. Weight loss is the primary goal in obesity treatment, and many different dietary interventions are tried for this purpose. Intermittent fasting is a diet that has become popular in recent years with the weight loss it provides and includes periods of fasting and feeding. In addition to providing weight loss, intermittent fasting also has positive effects on important risk factors such as glucoregulatory parameters, blood lipids, and oxidative stress. Intermittent fasting appears to be an effective and safe way to achieve weight loss in obesity. It could also have therapeutic effects on obesity-related diseases. The aim of this review was to bring together up-to-date information on the effects of intermittent fasting on obesity and various obesity-related diseases, mechanisms of action, possible benefits and harms, and potential uses.

Ramadan intermittent fasting reduces visceral fat and improves gastrointestinal motility

BACKGROUND

Ramadan is a model of intermittent fasting linked with possible beneficial effects. Scarce information, however, is available about the combined effects of Ramadan intermittent fasting (RIF) on anthropometric and metabolic indices, gastrointestinal symptoms, and motility.

METHODS

In 21 healthy Muslims, we assessed the impact of RIF on caloric intake, physical activity, gastrointestinal symptoms and motility (gastric/gallbladder emptying by ultrasonography, orocaecal transit time by lactulose breath test), anthropometric indices, subcutaneous and visceral fat thickness (ultrasonography), glucose and lipid homeostasis.

RESULTS

Mean caloric intake decreased from a median of 2069 kcal (range 1677-2641) before Ramadan to 1798 kcal (1289-3126) during Ramadan and increased again to 2000 kcal (1309-3485) after Ramadan. Although physical activity remained stable before, during, and after RIF, body weight, body mass index and waist circumference decreased in all subjects and in both genders, together with a significant decrease in subcutaneous and visceral fat thickness and insulin resistance. The postprandial gastric emptying speed was significantly faster after than before RIF. Fasting gallbladder volume was about 6% smaller after, than before Ramadan, with a stronger and faster postprandial gallbladder contraction. After RIF, lactulose breath test documented increased microbiota carbohydrate fermentation (postprandial H2 peak), and faster orocaecal transit time. RIF also significantly improved gastric fullness, epigastric pain and heartburn.

CONCLUSIONS

RIF generates, in healthy subjects, multiple systemic beneficial effects in terms of fat burden, metabolic profile, gastrointestinal motility and symptoms. Further comprehensive studies should assess the potential beneficial effects of RIF in diseased people.

A Bibliometric Analysis of Alternate-Day Fasting from 2000 to 2023

Alternate-day fasting (ADF) is becoming more popular since it may be a promising diet intervention for human health. Our study aimed to conduct a comprehensive bibliometric analysis to investigate current publication trends and hotspots in the field of ADF. Publications regarding ADF were identified from the Web of Science Core Collection (WOSCC) database. VOSviewer 1.6.16 and Online Analysis Platform were used to analyze current publication trends and hotspots. In total, there were 184 publications from 362 institutions and 39 countries/regions, which were published in 104 journals. The most productive countries/regions, institutions, authors, and journals were the USA, University of Illinois Chicago, Krista A. Varady, and Nutrients, respectively. The first high-cited publication was published in PNAS and authored by R. Michael Anson, and it was also the first article about ADF. The top five keywords with the highest frequency were as follows: calorie restriction, weight loss, intermittent fasting, obesity, and body weight. In conclusion, this is the first comprehensive bibliometric analysis related to ADF. The main research hotspots and frontiers are ADF for obesity and cardiometabolic risk, and ADF for several different population groups including healthy adults and patients with diabetes, nonalcoholic fatty liver disease (NAFLD), and cancer. The number of studies about ADF is relatively small, and more studies are needed to extend our knowledge about ADF, to improve human health.

Intermittent Fasting and Its Effects on Weight, Glycemia, Lipids, and Blood Pressure: A Narrative Review

Metabolic syndrome (MetS) has become a significant public health concern globally. Weight managementis crucial in controlling MetS risk factors, making energy balance and weight loss strategies important in nutrition recommendations. Intermittent fasting (IF) has gained traction as a dietary approach for weight management and cardiovascular risk reduction. However, the effects of IF on cardiovascular risk factors have been inconsistent in previous studies. This review aims to summarize the effects of various types of IF on body mass index (BMI), glycemia, lipid profile, and blood pressure, while providing insights into their clinical implications. A comprehensive search of interventional studies and meta-analyses was conducted, and the results were analyzed. The findings indicate that different types of IF lead to mixed effects. Time-restricted eating (TRE) and alternate-day fasting (ADF) consistently showed decreases in BMI, while the outcomes of intermittent energy restriction (IER) were more uncertain. The effects of IF on glycemia and lipid profile were also variable, with TRE and ADF generally showing positive results. However, the impact of IER remained inconsistent. More research is needed to understand the long-term effects and optimal implementation of IF for managing metabolic syndrome and cardiovascular risk factors.

The Alteration of the Gut Microbiome during Ramadan Offers a Novel Perspective on Ramadan Fasting: A Pilot Study

An intermittent fasting regimen is widely perceived to lead to various beneficial health effects, including weight loss, the alleviation of insulin resistance, and the restructuring of a healthy gut microbiome. Because it shares certain commonalities with this dietary intervention, Ramadan fasting is sometimes misinterpreted as intermittent fasting, even though there are clear distinctions between these two regimens. The main purpose of this study is to verify whether Ramadan fasting drives the same beneficial effects as intermittent fasting by monitoring alterations in the gut microbiota. We conducted a study involving 20 Muslim individuals who were practicing Ramadan rituals and assessed the composition of their gut microbiomes during the 4-week period of Ramadan and the subsequent 8-week period post-Ramadan. Fecal microbiome analysis was conducted, and short-chain fatty acids (SCFAs) were assessed using liquid-chromatography-mass spectrometry. The observed decrease in the levels of SCFAs and beneficial bacteria during Ramadan, along with the increased microbial diversity post-Ramadan, suggests that the daily diet during Ramadan may not provide adequate nutrients to maintain robust gut microbiota. Additionally, the notable disparities in the functional genes detected through the metagenomic analysis and the strong correlation between Lactobacillus and SCFAs provide further support for our hypothesis.

Abdominal Massage Ameliorates Inguinal Fat Accumulation via Augmentation of PPARγ Signaling in High-Fat Diet-Induced Obese Mice

Purpose

With the increase in prevalence and decrease in age of the obese population, safer weight loss methods have attracted growing attention. While abdominal massage (AM) has been clinically proven for weight loss, the mechanism thereof has yet to be elucidated. We aimed to investigate the effect of AM on abdominal fat in obese mice fed a high-fat diet and explore the possible mechanisms involved.

Materials and Methods

Male C57BL/6J mice were fed a high-fat diet for 16 weeks and then treated with AM for 5 weeks; mice fed a standard diet were used as normal controls. Blood and adipose tissue, including inguinal white adipose tissue (WAT) and epididymal WAT, were collected from the mice after the intervention. We explored the mechanism of weight reduction through inguinal WAT transcriptome sequencing, quantitative real-time polymerase chain reaction (PCR) validation, and Western blot.

Results

The results revealed that AM decreased fat mass, weight, glucose, and serum lipid levels. Meanwhile, AM enhanced the expression of the peroxisome proliferator-activated receptor gamma (PPARγ) and other downstream genes (Fabp4, Acox3, Pck1, and Aqp7) in inguinal WAT. In addition, AM increased the expression of PPARγ protein.

Conclusion

AM may promote fatty acid oxidation, lipid metabolism, and glucose homeostasis by activating the PPARγ signaling pathway in inguinal WAT, thereby exhibiting therapeutic efficacy against obesity, even in the presence of a persistent high-fat diet.

Effects of intermittent fasting on cognitive health and Alzheimer's disease

OBJECTIVE

Caloric restriction by intermittent fasting produces several metabolic changes, such as increased insulin sensitivity and use of ketone bodies as energy sources. In humans, intermittent fasting has been studied in hypertension, diabetes, and related conditions, but, to date, not as a strategy to reduce the risk of emergent dementia. In this scoping review, the relevance of intermittent fasting as a potential preventive intervention for Alzheimer's dementia is explored.

BACKGROUND

The beneficial effects of calorie restriction have been documented in animals and humans. Decreased oxidative stress damage and attenuated inflammatory responses are associated with intermittent fasting. These changes have a favorable impact on the vascular endothelium and stress-induced cellular adaptation.

RESULTS

Physiological alterations associated with fasting have profound implications for pathological mechanisms associated with dementias, particularly Alzheimer's disease. Compared with ad libitum feeding, caloric restriction in animals was associated with a reduction in β-amyloid accumulation, which is the cardinal pathological marker of Alzheimer's disease. Animal studies have demonstrated synaptic adaptations in the hippocampus and enhanced cognitive function after fasting, consistent with these theoretical frameworks. Furthermore, vascular dysfunction plays a crucial role in Alzheimer's disease pathology, and intermittent fasting promotes vascular health.

CONCLUSIONS

These observations lead to a hypothesis that intermittent fasting over the years will potentially reverse or delay the pathological process in Alzheimer's disease.