Intermittent Fasting Promotes Fat Loss With Lean Mass Retention, Increased Hypothalamic Norepinephrine Content, and Increased Neuropeptide Y Gene Expression in Diet-Induced Obese Male Mice

Intermittent fasting disrupts hippocampal-dependent memory and norepinephrine content in aged male and female mice

Intermittent fasting (IMF) is associated with many health benefits in animals and humans. Yet, little is known if an IMF diet affects mood and cognitive processing. We have previously identified that IMF in diet-induced obese males increases norepinephrine and dopamine content in the hypothalamus and increases arcuate neuropeptide Y (NPY) gene expression more than in ad libitum control males. This suggests that IMF may improve cognition through activation of the hindbrain norepinephrine neuronal network and reverse the age-dependent decline in NPY expression. Less is known about the association between anxiety and IMF. Although, in humans, IMF during Ramadan may alleviate anxiety. Here, we address the impact of IMF on anxiety-like behavior using the open field test, hippocampal-dependent memory using the Y-maze and spatial object recognition, and hippocampal-independent memory using novel object recognition in middle-aged male and female (12 mo) and aged male and female (18 mo) mice. Using ELISA, we determined norepinephrine (NE) content in the dorsal hippocampus (DH) and prefrontal cortex (PFC). We also investigated gene expression in the arcuate nucleus (ARC), the lateral hypothalamus (LH), and the locus coeruleus (LC). In IMF-treated females at both ages, we observed an improvement in spatial navigation although an impairment in spatial object orientation. IMF-treated females (12 mo) had a reduction and IMF-treated males (12 mo) displayed an improvement in novel object recognition memory. IMF-treated females (18 mo) exhibited anxiolytic-like behavior and increased locomotion. In the DH, IMF-treated males (12 mo) had a greater amount of NE content and IMF-treated males (18 mo) had a reduction. In the ARC, IMF-treated males (12 mo) exhibited an increase in Agrp and Npy and a decrease in Adr1a. In the ARC, IMF-treated males (18 mo) exhibited an increase in Npy and a decrease in Adr1a; females had a trending decrease in Cart. In the LH at 12 months, IMF-treated males had a decrease in Npy5r, Adr1a, and Adr1b; both males and females had a reduction in Npy1r. In the LH, IMF-treated females (18 mo) had a decrease in Hcrt. In the LC at both ages, mice largely exhibited sex effects. Our findings indicate that IMF produces alterations in mood, cognition, DH NE content, and ARC, LH, and LC gene expression depending on sex and age.

Alternate-day fasting ameliorated anxiety-like behavior in high-fat diet-induced obese mice

Alternate-day fasting (ADF) has been reported to reduce body weight, neuroinflammation, and oxidative stress damage. However, it is not known whether ADF affects obesity-induced anxiety-like behavior. Here, male C57BL/6 mice were given an alternate fasting and high-fat diet (HFD) or standard chow diet (SD) every other day for 16 or 5 weeks. After the intervention, the degree of anxiety of the mice was evaluated by the open field test (OFT) and the elevated plus maze (EPM) test. Pathological changes in the hippocampus, the expression of Sirt1 and its downstream protein monoamine oxidase A (MAO-A) in the hippocampus, and the expression of 5-hydroxytryptamine (5-HT) were detected. Compared with HFD-fed mice, HFD-fed mice subjected to ADF for 16 weeks had a lower body weight but more brown adipose tissue (BAT), less anxiety behavior, and less pathological damage in the hippocampus, and lower expression of Sirt1 and MAO-A protein and higher 5-HT levels in the hippocampus could be observed. In addition, we noted that long-term ADF intervention could cause anxiety-like behavior in SD mice. Next, we changed the intervention time to 5 weeks. The results showed that short-term ADF intervention could reduce the body weight and increase the BAT mass of SD mice, but it did not affect anxiety. These results indicated that long-term ADF ameliorated obesity-induced anxiety-like behavior and hippocampal damage, but caused anxiety in normal-weight mice. Short-term ADF did not produce adverse emotional reactions in normal-weight mice. Here, we might provide new ideas for the treatment of obesity-induced anxiety.

Does an alternate-day modified fasting diet improve premenstrual syndrome symptoms and health-related quality of life in obese or overweight women with premenstrual syndrome? A randomized, controlled trial

Background

Premenstrual syndrome disorder (PMS) is a condition that affects health-related quality of life (HRQoL) and encompasses a variety of symptoms, including psychological, physical, and behavioral symptoms. Some evidence suggests that an increase in body mass index (BMI) can reduce both HRQoL and menstrual quality. This is because the body fat tissue can affect menstrual cycles by changing the estrogen/progesterone ratio. This study investigated the impact of two diets alternate-day modified fasting (ADMF) and daily calorie restriction (DCR) - on PMS syndrome and HRQoL.

Methods

The study was a randomized controlled, open-label trial that lasted for 8 weeks and involved 60 obese/overweight women. Participants were recruited from the Health Service Centers of Kashan University of Medical Sciences using simple random sampling. The study compared the impact of the ADMF and DCR diets on HRQoL and PMS symptoms. Patients were classified based on their BMI and age and then allocated to either the intervention (ADMF) or control (DCR) group using a random numbers table. The study measured HRQoL, PMS severity, weight, BMI, body fat mass, waist circumference, fat-free mass, and skeletal muscle mass before and after the study. The study had an almost 18% dropout rate.

Results

Significant improvements were observed in mood lability (p = 0.044) and expressed anger (p < 0.001) in relation to PMS symptoms. However, no significant differences were detected in the changes of other COPE subscales. The ADMF diet had a significant impact on the 12-item Short-Form Health Survey (SF-12) total score (p < 0.001) and physical function subscales (p = 0.006) as well as mental health (p < 0.001) when compared to the control diet. This implies that the ADMF diet increased both SF-12 total score and its subscales. The intervention led to improvements in HRQoL, physical function, and mental health. Additionally, significant improvements in BMI and weight were observed between the two groups pre- and post-study (p < 0.001). Anthropometric data, including body fat mass and waist circumference, showed a significant improvement (p < 0.001 and p = 0.029, respectively) before and after the study. However, there were no significant changes in fat-free mass (p = 0.936) and skeletal muscle mass (p = 0.841) between the two groups.

Conclusion

The study suggested that ADMF can improve HRQoL, mood lability, and expressed anger. It also showed that ADMF can reduce waist circumference, weight, and body fat mass in obese/overweight women.

Clinical trial registration

The Iranian Registry of Clinical Trials (IRCT20220522054958N1).

CCE and EODF as two distinct non-shivering thermogenesis models inducing weight loss

Increasing energy expenditure and reducing energy intake are considered two classical methods to induce weight loss. Weight loss through physical methods instead of drugs has been a popular research topic nowadays, but how these methods function in adipose and cause weight loss in body remains unclear. In this study, we set up chronic cold exposure (CCE) and every-other-day fasting (EODF) as two distinct models in long-term treatment to induce weight loss, recording their own characteristics in changes of body temperature and metabolism. We investigated the different types of non-shivering thermogenesis induced by CCE and EODF in white and brown adipose tissue through sympathetic nervous system (SNS), creatine-driven pathway, and fibroblast growth factor 21 (FGF21)-adiponectin axis. CCE and EODF could reduce body weight, lipid composition, increase insulin sensitivity, promote the browning of white fat, and increase the expression of endogenous FGF21 in adipose tissue. CCE stimulated the SNS and increased the thermogenic function of brown fat, and EODF increased the activity of protein kinase in white fat. In this study, we further explained the thermogenic mechanism function in adipose and metabolic benefits of the stable phenotype through physical treatments used for weight loss, providing more details for the literature on weight loss models. The influence on metabolism, non-shivering thermogenesis, endogenous FGF21, and ADPN changes in the long-term treatment of distinct methods (increasing energy expenditure and decreasing energy intake) to induce weight loss.

Effects of Diet and Exercise on Circadian Rhythm: Role of Gut Microbiota in Immune and Metabolic Systems

A close relationship exists between the intestinal microbiota and the circadian rhythm, which is mainly regulated by the central-biological-clock system and the peripheral-biological-clock system. At the same time, the intestinal flora also reflects a certain rhythmic oscillation. A poor diet and sedentary lifestyle will lead to immune and metabolic diseases. A large number of studies have shown that the human body can be influenced in its immune regulation, energy metabolism and expression of biological-clock genes through diet, including fasting, and exercise, with intestinal flora as the vector, thereby reducing the incidence rates of diseases. This article mainly discusses the effects of diet and exercise on the intestinal flora and the immune and metabolic systems from the perspective of the circadian rhythm, which provides a more effective way to prevent immune and metabolic diseases by modulating intestinal microbiota.

Alternate-day modified fasting diet improves weight loss, subjective sleep quality and daytime dysfunction in women with obesity or overweight: a randomized, controlled trial

Background

Both sleep time and quality can be associated with overweight or obesity. In obese people, visceral fat tissue develops, which results in an increment in the production of cytokines. The increased production of inflammatory cytokines can disturb the sleep/wake cycle. Therefore, weight loss by reducing fat tissue can improve sleep disorders. Intermittent fasting diets are popular and effective diets that can decrease body weight and improve anthropometric data and body composition. The present study aimed to evaluate the effect of Alternate-day Modified Fasting (ADMF) on sleep quality, body weight, and daytime sleepiness.

Methods

Classification of 56 obese or overweight women, based on age and body mass index (BMI), was done using stratified randomization. Then individuals were assigned to the ADMF group (intervention) or Daily Calorie Restriction (CR) group (control) using the random numbers table for 8 weeks. We measured the Pittsburgh sleep quality Index (PSQI), weight, BMI, and the Epworth sleepiness scale (ESS) as primary outcomes and assessed subjective sleep quality (SSQ), sleep latency, sleep disturbances, habitual sleep efficiency, daytime dysfunction, and sleep duration as secondary outcomes at baseline and after the study.

Results

Following an ADMF diet resulted in a greater decrease in weight (kg) [-5.23 (1.73) vs. -3.15 (0.88); P < 0.001] and BMI (kg/m²) [-2.05 (0.66) vs. -1.17 (0.34); P < 0.001] compared to CR. No significant differences were found in the changes of PSQI [-0.39 (1.43) vs. -0.45 (1.88); P = 0.73] and ESS [-0.22 (1.24) vs. -0.54 (1.67); P = 0.43] between two groups. Also, following the ADMF diet led to significant changes in SSQ [-0.69 (0.47) vs. -0.08 (0.40); P = <0.001], and daytime dysfunction [-0.65 (0.57) vs. 0.04 (0.75); P: 0.001] in compare with CR diet.

Conclusion

These results suggested that an ADMF could be a beneficial diet for controlling body weight and BMI. The ADMF diet didn't affect PSQI and ESS in women with overweight or obesity but significantly improved SSQ and daytime dysfunction.

Clinical Trial Registration

The Iranian Registry of Clinical Trials (IRCT20220522054958N3), https://www.irct.ir/trial/64510.

Intermittent fasting combined with exercise training reduces body mass and alleviates hypothalamic disorders induced by high-fat diet intake

High-fat diet consumption causes hypothalamic inflammation, dysregulating the leptin pathway, which, in turn, compromises the modulation of hypothalamic neuronal activities and predisposes obesity development. Intermittent fasting (IF) and exercise training (ET) have been demonstrated as efficient interventions to modulate hypothalamic inflammation and neuronal activity. However, no studies have evaluated whether combining these interventions could induce better results in reestablishing hypothalamic homeostasis disrupted by high-fat diet intake. The 8-week-old male C57BL/6 mice were randomly assigned into two groups: sedentary mice fed a standard diet (CT), and sedentary mice fed a high-fat diet (HF). After 8 weeks of an HF diet, part of the HF group (now 16 weeks old) was randomly subjected to different interventions for 6 weeks: HF-IF = HF diet mice submitted to IF; HF-T = HF diet mice submitted to ET; HF-IFT = HF diet mice submitted to IF and ET. All interventions decreased the body weight gain induced by high-fat diet intake, associated with reduced calorie consumption in week 14. Only the HF-IFT group presented improved serum insulin, leptin, resistin, and Tnf-alpha levels concomitantly with decreased hypothalamic inflammation. The HF-IFT group also demonstrated increased Pomc mRNA expression associated with enhanced pSTAT3 expression in the hypothalamic arcuate and ventromedial hypothalamic nuclei. Our data indicate that the beneficial effects of the combination of IF and ET on energy homeostasis are associated with increased leptin sensitivity in the hypothalamic arcuate nucleus and ventromedial hypothalamic nucleus, which is likely due to an improvement in hypothalamic inflammatory pathways in these nuclei.

Effect of modified alternate day fasting diet on the severity of premenstrual syndrome and health-related quality of life in women with overweight or obesity: a trial study protocol

INTRODUCTION

Premenstrual syndrome (PMS) includes a range of physical, behavioural and psychological symptoms and decreases women's health-related quality of life (HRQoL). It has been proposed that increased body mass index (BMI) is associated with menstrual problems and decreased HRQoL. The body fat amount plays a role in menstrual cycles by altering the oestrogen/progesterone ratio. Alternate day fasting as an unusual diet results in the improvement of anthropometric indices and reduction of body weight. This study aims to investigate the effect of a daily calorie restriction diet and a modified alternate day fasting diet on PMS and HRQoL.

METHODS AND ANALYSIS

This 8-week open-label parallel randomised controlled trial examines the impact of a modified alternate-day fasting diet and daily caloric restriction on the severity of PMS and HRQoL in obese or overweight women. Using simple random sampling, women between the ages of 18 years and 50 years and 25 ≤ BMI ˂ 40 who meet the inclusion and exclusion criteria will be chosen from the Kashan University of Medical Sciences Centre. Patients will be randomised, based on BMI and age through stratified randomisation. Then by the random numbers table, they are allocated to fasting (intervention) or daily calorie restriction (control) groups. Outcomes are chosen for the trial: the difference in the severity of PMS, HRQoL, BMI, body fat mass, fat-free mass, waist-to-hip ratio, waist circumference, hip circumference, per cent body fat, skeletal muscle mass and visceral fat area from baseline to 8 weeks.

ETHICS AND DISSEMINATION

The Kashan University of Medical Sciences Ethics Committee has approved the trial (IR.KAUMS.MEDNT.REC.1401.003) (17 April 2022). Results will be published in peer-reviewed academic journals and the participants will be informed via phone calls.

TRIAL REGISTRATION NUMBER

IRCT20220522054958N1.

Combined effects of intermittent fasting with swimming-based high intensity intermittent exercise training in Wistar rats

High caloric intake and physical inactivity are known precursors to the development of several chronic metabolic diseases. For obesity and sedentarism, High Intensity Intermittent Exercise (HIIE) and Intermittent Fasting (IF) have emerged as individual strategies to attenuate their negative effects by improving metabolism. To study their combined effects, Wistar male rats (n = 74, 60 days old) were divided into four groups: Sedentary Control (C), swimming-based HIIE only (HIIE), Intermittent Fasting only (IF), and swimming-based HIIE associated with Intermittent Fasting (HIIE/IF). Over an eight-week period swimming performance, body composition, weight and feeding behavior were analyzed. The final morphology of white adipose tissue showed a significant reduction in adipocyte size consistent with a higher number of cells per area in exercised animals (vs C and IF, p < 0.05), which also displayed characteristics of browning through UCP-1 levels and CD31 staining. These results suggest that the increased performance in the HIIE/IF group is, in part, by modifications of WAT metabolism through the browning process.

Comparison of the effect of modified intermittent fasting and daily calorie restriction on sleep quality, anthropometric data, and body composition in women with obesity or overweight: study protocol of a randomized controlled trial

BACKGROUND

Sleep disturbances are common in nearly one-third of adults. Both low quality of sleep and sleep time could be related to increased obesity. An increase in visceral adipose tissue can result in the secretion of inflammatory cytokines. Inflammatory cytokines can lead to a disturbance of the sleep-wake rhythm. Therefore, weight loss may improve sleep quality and duration. Intermittent fasting diet as a popular diet reduces body weight and improves anthropometric indices. This study is performed to further investigate the effect of a modified intermittent fasting diet on sleep quality and anthropometric indices.

METHODS

This is an open-label randomized controlled trial to evaluate the effect of daily calorie restriction (control) and modified intermittent fasting (intervention) on sleep quality, anthropometric data, and body composition in women with obesity or overweight for 8 weeks. Fifty-six participants will be classified using stratified randomization based on body mass index (BMI) and age. Then, participants will be assigned to one of the two groups of intervention or control using the random numbers table. The sleep quality, daytime sleepiness, and insomnia will be evaluated by using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Insomnia Severity Index respectively. The primary outcomes chosen for the study were as follows: the difference in sleep quality, daytime sleepiness, insomnia, BMI, fat-free mass (FFM), body fat mass, waist circumference, and waist-to-hip ratio from baseline to 8 weeks. Secondary outcomes chosen for the study were as follows: the difference in hip circumference, the visceral fat area, percent body fat, soft lean mass, skeletal muscle mass, extracellular water ratio, and total body water from baseline to 8 weeks.

DISCUSSION

This study will investigate the effect of intermittent fasting intervention compared with daily calorie restriction on sleep quality and anthropometric indices. The information gained will enhance our understanding of fasting interventions, which can be used to improve clinical dietary recommendations. The findings will help to disclose as yet the unknown relationship between diet and sleep quality.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20220522054958N3. Registered on 8 July 2022. https://www.irct.ir/trial/64510 .

Exploring the role of ketone bodies in the diagnosis and treatment of psychiatric disorders

In recent times, advances in the field of metabolomics have shed greater light on the role of metabolic disturbances in neuropsychiatric conditions. The following review explores the role of ketone bodies and ketosis in both the diagnosis and treatment of three major psychiatric disorders: major depressive disorder, anxiety disorders, and schizophrenia. Distinction is made between the potential therapeutic effects of the ketogenic diet and exogenous ketone preparations, as exogenous ketones in particular offer a standardized, reproducible manner for inducing ketosis. Compelling associations between symptoms of mental distress and dysregulation in central nervous system ketone metabolism have been demonstrated in preclinical studies with putative neuroprotective effects of ketone bodies being elucidated, including effects on inflammasomes and the promotion of neurogenesis in the central nervous system. Despite emerging pre-clinical data, clinical research on ketone body effectiveness as a treatment option for psychiatric disorders remains lacking. This gap in understanding warrants further investigating, especially considering that safe and acceptable ways of inducing ketosis are readily available.

Metabolic gene signature in white adipose tissue of oral doses raspberry ketone [4-(4-hydroxyphenyl)-2-butanone] that prevent diet-induced weight gain and induce loss of righting reflex

Raspberry ketone (RK; [4-(4-hydroxyphenyl)-2-butanone]) is a synthetic flavoring agent and dietary supplement for weight control. This study investigated the metabolic signature of oral doses of RK that prevent weight gain or promote loss of righting reflex (LORR) in C57Bl/6J mice. Daily RK 200 mg/kg prevented high-fat diet (HFD; 45% Kcal fat) fed weight gain (∼8% reduction) over 35 days. RNA-seq of inguinal white adipose tissue (WAT) performed in males revealed 12 differentially expressed genes. Apelin (Apln) and potassium voltage-gated channel subfamily C member (Kcnc3) expression were elevated with HFD and normalized with RK dosing, which was confirmed by qPCR. Acute RK 640 mg/kg produced a LORR with a <5 min onset with a >30 min duration. Acute RK 200 mg/kg increased gene expression of Apln, Kcnc3, and nuclear factor erythroid 2-related factor 2 (Nrf2), but reduced acetyl-COA carboxylase (Acc1) and NAD(P)H quinone dehydrogenase 1 (Nqo1) in inguinal WAT. Acute RK 640 mg/kg elevated interleukin 6 (Il 6) and heme oxygenase 1 (Hmox1) expression, but reduced Nrf2 in inguinal and epididymal WAT. Our findings suggest that RK has a dose-dependent metabolic signature in WAT associated with either weight control or LORR.

Intermittent fasting: Describing engagement and associations with eating disorder behaviors and psychopathology among Canadian adolescents and young adults

Intermittent fasting has grown in popularity over the past several years. However, intermittent fasting has also been shown to relate to eating disorder behaviors and psychopathology, yet little research has explored this relationship in epidemiological samples. Therefore, the aims of this study were to determine prevalence and characteristics of engagement in intermittent fasting, and associations with eating disorder behaviors and psychopathology. Data from the Canadian Study of Adolescent Health Behaviors, a national study of Canadian adolescents and young adults (N = 2762) were analyzed. Multiple modified Poisson regression analyses were conducted to determine the association between intermittent fasting (past 12 months and 30 days) and eating disorder behaviors and psychopathology (measured using the Eating Disorder Examination Questionnaire). Overall, 47.7 % of women, 38.4 % of men, and 52.0 % of transgender/gender non-conforming (TGNC) participants reported engaging in intermittent fasting in the past 12 months. Intermittent fasting in the past 12 months and 30 days was significantly associated with eating disorder psychopathology among women, men, and TGNC participants. Varying patterns of association between intermittent fasting and eating disorder behaviors were found across genders, with the most consistent relationships between intermittent fasting and ED behaviors in women. Findings underscore the common nature of intermittent fasting among a large, community sample of adolescents and young adults across Canada, as well as associated eating disorder behaviors and psychopathology. Continued research is needed to further understand the effects of intermittent fasting, as clinical and public health efforts are needed to protect the health of adolescent and young adults.

Alternate-day fasting prevents non-alcoholic fatty liver disease and working memory impairment in diet-induced obese mice

Alternate-day fasting (ADF) regimen has been reported to alleviate obesity and insulin resistance. However, the effects of ADF on preventing diet-induced non-alcoholic fatty liver disease (NAFLD) and related cognitive deficits are still elusive. In the present study, a high-fat diet (HFD)-induced obese (DIO) C57BL/6 mouse model was established. Mice were treated with a 4-week long ADF regimen and/or switching the diet to a standard diet. ADF reduced lipid accumulation, activated AMPK/ULK1 signaling, and suppressed the phosphorylation of mTOR. Also, ADF inhibited lipid accumulation and inflammatory responses in the white adipose tissue and down-regulated expressions of PPAR-γ and cytokines. Moreover, ADF improved the working memory and synaptic structure in the DIO mice and upregulated PSD-95 and BDNF in the hippocampus. ADF reduced oxidative stress and microglial over-activation in the CNS. These results suggest that ADF attenuates NAFLD development in the liver of DIO mice, which is related to the mediating effects of ADF on autophagy and energy metabolism. ADF also enhanced cognitive function, which could be partly explained by the down-regulated peripheral inflammatory responses. This study indicates that ADF could be a promising intervention for alleviating NAFLD development and cognitive decline.

Fatty acids homeostasis during fasting predicts protection from chemotherapy toxicity

Fasting exerts beneficial effects in mice and humans, including protection from chemotherapy toxicity. To explore the involved mechanisms, we collect blood from humans and mice before and after 36 or 24 hours of fasting, respectively, and measure lipid composition of erythrocyte membranes, circulating micro RNAs (miRNAs), and RNA expression at peripheral blood mononuclear cells (PBMCs). Fasting coordinately affects the proportion of polyunsaturated versus saturated and monounsaturated fatty acids at the erythrocyte membrane; and reduces the expression of insulin signaling-related genes in PBMCs. When fasted for 24 hours before and 24 hours after administration of oxaliplatin or doxorubicin, mice show a strong protection from toxicity in several tissues. Erythrocyte membrane lipids and PBMC gene expression define two separate groups of individuals that accurately predict a differential protection from chemotherapy toxicity, with important clinical implications. Our results reveal a mechanism of fasting associated with lipid homeostasis, and provide biomarkers of fasting to predict fasting-mediated protection from chemotherapy toxicity.

Fasting has been reported to protect from chemotherapy-associated toxicity. Here, the authors show that fatty acid profiles in erythrocyte membranes and gene expression from peripheral blood mononuclear cells are associated to the fasting-mediated benefits during cancer treatment in mice and patients.

Effectiveness of Early Time-Restricted Eating for Weight Loss, Fat Loss, and Cardiometabolic Health in Adults With Obesity: A Randomized Clinical Trial

Importance

It is unclear how effective intermittent fasting is for losing weight and body fat, and the effects may depend on the timing of the eating window. This randomized trial compared time-restricted eating (TRE) with eating over a period of 12 or more hours while matching weight-loss counseling across groups.

Objective

To determine whether practicing TRE by eating early in the day (eTRE) is more effective for weight loss, fat loss, and cardiometabolic health than eating over a period of 12 or more hours.

Design, Setting, and Participants

The study was a 14-week, parallel-arm, randomized clinical trial conducted between August 2018 and April 2020. Participants were adults aged 25 to 75 years with obesity and who received weight-loss treatment through the Weight Loss Medicine Clinic at the University of Alabama at Birmingham Hospital.

Interventions

All participants received weight-loss treatment (energy restriction [ER]) and were randomized to eTRE plus ER (8-hour eating window from 7:00 to 15:00) or control eating (CON) plus ER (≥12-hour window).

Main Outcomes and Measures

The co-primary outcomes were weight loss and fat loss. Secondary outcomes included blood pressure, heart rate, glucose levels, insulin levels, and plasma lipid levels.

Results

Ninety participants were enrolled (mean [SD] body mass index, 39.6 [6.7]; age, 43 [11] years; 72 [80%] female). The eTRE+ER group adhered 6.0 (0.8) days per week. The eTRE+ER intervention was more effective for losing weight (-2.3 kg; 95% CI, -3.7 to -0.9 kg; P = .002) but did not affect body fat (-1.4 kg; 95% CI, -2.9 to 0.2 kg; P = .09) or the ratio of fat loss to weight loss (-4.2%; 95% CI, -14.9 to 6.5%; P = .43). The effects of eTRE+ER were equivalent to reducing calorie intake by an additional 214 kcal/d. The eTRE+ER intervention also improved diastolic blood pressure (-4 mm Hg; 95% CI, -8 to 0 mm Hg; P = .04) and mood disturbances, including fatigue-inertia, vigor-activity, and depression-dejection. All other cardiometabolic risk factors, food intake, physical activity, and sleep outcomes were similar between groups. In a secondary analysis of 59 completers, eTRE+ER was also more effective for losing body fat and trunk fat than CON+ER.

Conclusions and Relevance

In this randomized clinical trial, eTRE was more effective for losing weight and improving diastolic blood pressure and mood than eating over a window of 12 or more hours at 14 weeks.

Trial Registration

ClinicalTrials.gov Identifier: NCT03459703.

Intermittent Fasting: Potential Utility in the Treatment of Chronic Pain across the Clinical Spectrum

Dietary behavior can have a consequential and wide-ranging influence on human health. Intermittent fasting, which involves intermittent restriction in energy intake, has been shown to have beneficial cellular, physiological, and system-wide effects in animal and human studies. Despite the potential utility in preventing, slowing, and reversing disease processes, the clinical application of intermittent fasting remains limited. The health benefits associated with the simple implementation of a 12 to 16 h fast suggest a promising role in the treatment of chronic pain. A literature review was completed to characterize the physiologic benefits of intermittent fasting and to relate the evidence to the mechanisms underlying chronic pain. Research on different fasting regimens is outlined and an overview of research demonstrating the benefits of intermittent fasting across diverse health conditions is provided. Data on the physiologic effects of intermittent fasting are summarized. The physiology of different pain states is reviewed and the possible implications for intermittent fasting in the treatment of chronic pain through non-invasive management, prehabilitation, and rehabilitation following injury and invasive procedures are presented. Evidence indicates the potential utility of intermittent fasting in the comprehensive management of chronic pain and warrants further investigation.

Exogenous Ketones and Lactate as a Potential Therapeutic Intervention for Brain Injury and Neurodegenerative Conditions

Metabolic dysfunction is a ubiquitous underlying feature of many neurological conditions including acute traumatic brain injuries and chronic neurodegenerative conditions. A central problem in neurological patients, in particular those with traumatic brain injuries, is an impairment in the utilization of glucose, which is the predominant metabolic substrate in a normally functioning brain. In such patients, alternative substrates including ketone bodies and lactate become important metabolic candidates for maintaining brain function. While the potential neuroprotective benefits of ketosis have been recognized for up to almost a century, the majority of work has focused on the use of ketogenic diets to induce such a state, which is inappropriate in cases of acute disease due to the prolonged periods of time (i.e., weeks to months) required for the effects of a ketogenic diet to be seen. The following review seeks to explore the neuroprotective effects of exogenous ketone and lactate preparations, which have more recently become commercially available and are able to induce a deep ketogenic response in a fraction of the time. The rapid response of exogenous preparations makes their use as a therapeutic adjunct more feasible from a clinical perspective in both acute and chronic neurological conditions. Potentially, their ability to globally moderate long-term, occult brain dysfunction may also be relevant in reducing lifetime risks of certain neurodegenerative conditions. In particular, this review explores the association between traumatic brain injury and contusion-related dementia, assessing metabolic parallels and highlighting the potential role of exogenous ketone and lactate therapies.

Intermittent fasting induces chronic changes in the hepatic gene expression of Red Jungle Fowl (Gallus gallus)

Background

Intermittent fasting (IF), the implementation of fasting periods of at least 12 consecutive hours on a daily to weekly basis, has received a lot of attention in recent years for imparting the life-prolonging and health-promoting effects of caloric restriction with no or only moderate actual restriction of caloric intake. IF is also widely practiced in the rearing of broiler breeders, the parent stock of meat-type chickens, who require strict feed restriction regimens to prevent the serious health problems associated with their intense appetites. Although intermittent fasting has been extensively used in this context to reduce feed competition and its resulting stress, the potential of IF in chickens as an alternative and complementary model to rodents has received less investigation. In both mammals and birds, the liver is a key component of the metabolic response to IF, responding to variations in energy balance. Here we use a microarray analysis to examine the liver transcriptomics of wild-type Red Jungle Fowl chickens fed either ad libitum, chronically restricted to around 70% of ad libitum daily or intermittently fasted (IF) on a 2:1 (2 days fed, 1 day fasted) schedule without actual caloric restriction. As red junglefowl are ancestral to domestic chicken breeds, these data serve as a baseline to which existing and future transcriptomic results from farmed birds such as broiler breeders can be compared.

Results

We find large effects of feeding regimen on liver transcriptomics, with most of the affected genes relating to energy metabolism. A cluster analysis shows that IF is associated with large and reciprocal changes in genes related to lipid and carbohydrate metabolism, but also chronic changes in genes related to amino acid metabolism (generally down-regulated) and cell cycle progression (generally up-regulated). The overall transcription pattern appears to be one of promoting high proliferative plasticity in response to fluctuations in available energy substrates. A small number of inflammation-related genes also show chronically changed expression profiles, as does one circadian rhythm gene.

Conclusions

The increase in proliferative potential suggested by the gene expression changes reported here indicates that birds and mammals respond similarly to intermittent fasting practices. Our findings therefore suggest that the health benefits of periodic caloric restriction are ubiquitous and not restricted to mammals alone. Whether a common fundamental mechanism, for example involving leptin, underpins these benefits remains to be elucidated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08533-5.

Using Intermittent Fasting as a Non-pharmacological Strategy to Alleviate Obesity-Induced Hypothalamic Molecular Pathway Disruption

Intermittent fasting (IF) is a popular intervention used to fight overweight/obesity. This condition is accompanied by hypothalamic inflammation, limiting the proper signaling of molecular pathways, with consequent dysregulation of food intake and energy homeostasis. This mini-review explored the therapeutic modulation potential of IF regarding the disruption of these molecular pathways. IF seems to modulate inflammatory pathways in the brain, which may also be correlated with the brain-microbiota axis, improving hypothalamic signaling of leptin and insulin, and inducing the autophagic pathway in hypothalamic neurons, contributing to weight loss in obesity. Evidence also suggests that when an IF protocol is performed without respecting the circadian cycle, it can lead to dysregulation in the expression of circadian cycle regulatory genes, with potential health damage. In conclusion, IF may have the potential to be an adjuvant treatment to improve the reestablishment of hypothalamic responses in obesity.

Weight-gain propensity and morphine withdrawal alters locomotor behavior and regional norepinephrine-related gene expression in male and female mice

Interactions between obesity and opioid use are poorly understood. The objective of this study was to determine whether phenotypic differences in diet-induced weight gain altered morphine withdrawal responses. Male and female C57BL/6J mice were characterized as obese prone (OP) or obese resistant (OR) based on median split in body weights following exposure to high-fat diet (45% fat). After classification into OP or OR, all mice were fed a low-fat diet (10% fat) for the remainder of the study (≥5 weeks) to remain weight matched. Mice were treated with a 7-day escalating dosing scheme of morphine (20-100 mg/kg; IP) or saline and underwent a spontaneous withdrawal. Morphine-induced weight loss was restored by withdrawal day 7. On withdrawal day 8, male OP demonstrated less total time mobile in the open field test (OFT). In females, OR-morphine traveled less distance than OR-saline, and OR-morphine spent less time mobile compared with all other groups in the OFT. Female OP also increased time spent in the center of the apparatus, regardless of treatment. On withdrawal day 8, relative gene expression was measured by qPCR. For males, expression of dopamine beta-hydroxylase (dbh), alpha-adrenergic receptor 2 a (adra2a), and orexin receptor 1 (orx1) were increased in the locus coeruleus (LC) region of OP mice, regardless of treatment. In comparison, in females, dbh and adra2a were decreased in the LC region of OP mice, regardless of treatment. Also, in the LC region of females, OP-morphine had lower expression of alpha-adrenergic receptor 1 a (adra1a) than OR-morphine and OP-saline. In the hypothalamic paraventricular nucleus (PVN) of females, adra2a was increased in OP-morphine compared with OP-saline and OR-morphine. Our findings suggest morphine withdrawal responses and regional expression of noradrenergic-related genes are differentially influenced by weight gain propensity.

Benefits, mechanisms, and risks of intermittent fasting in metabolic syndrome and type 2 diabetes

One of the emergent nutritional strategies for improving multiple features of cardiometabolic diseases is the practice of intermittent fasting (IF), which consists of alternating periods of eating and fasting. IF can reduce circulating glucose and insulin levels, fat mass, and the risk of developing age-related pathologies. IF appears to upregulate evolution-conserved adaptive cellular responses, such as stress-response pathways, autophagy, and mitochondrial function. IF was also observed to modulate the circadian rhythms of hormones like insulin or leptin, among others, which levels change in conditions of food abundance and deficit. However, some contradictory results regarding the duration of the interventions and the anterior metabolic status of the participants suggest that more and longer studies are needed in order to draw conclusions. This review summarizes the current knowledge regarding the role of IF in the modulation of mechanisms involved in type 2 diabetes, as well as the risks.

Effect of Intermittent Fasting on Glucose Homeostasis and Bone Remodeling in Glucocorticoid-Induced Osteoporosis Rat Model

Background

The present study examined the effect of intermittent fasting (IF) on bone mineral content (BMC) and bone mineral density (BMD) and the markers of bone remodeling in a glucocorticoid-induced osteoporosis (GIO) rat model.

Methods

Forty male rats were allocated to 4 groups (N=10 per group): control group of normal rats; control+IF group (normal rats subjected to IF for 16–18 hr daily for 90 days); dexamethasone (DEX) group: (DEX [0.5 mg i.p.] for 90 days); and DEX+IF group (DEX and IF for 90 days). By the end of the experiment, BMD and BMC in the right tibia were measured. Serum levels of the following were measured: glucose; insulin; triglycerides (TGs); total cholesterol; parathyroid hormone (PTH); osteoprotegerin (OPG); receptor activator of nuclear factor-κB (RANK); bone-resorbing cytokines, including bone deoxypyridinoline (DPD), N-terminal telopeptide of collagen type I (NTX-1), and tartrate-resistant acid phosphatase 5b (TRAP-5b); and bone-forming cytokines, including alkaline phosphatase (ALP) and osteocalcin (OC).

Results

DEX administration for 90 days resulted in significantly increased serum levels of glucose, insulin, TGs, cholesterol, PTH, OPG, DPD, NTX-1, and TRAP-5b and significantly decreased BMD, BMC, and serum levels of RANK, OC, and ALP (all P<0.05). IF for 90 days significantly improved all these parameters (all P<0.05).

Conclusions

IF corrected GIO in rats by inhibiting osteoclastogenesis and PTH secretion and stimulating osteoblast activity.

Intermittent Fasting Reshapes the Gut Microbiota and Metabolome and Reduces Weight Gain More Effectively Than Melatonin in Mice

Background: Intermittent fasting (IF) can reduce energy intake and body weight (BW). Melatonin has many known functions, which include reducing appetite and preventing excessive weight gain. Objective: This study aimed to investigate the effects of IF on body fat and the gut microbiota and metabolome as well as a potential interaction with melatonin. Methods: Male C57BL/6J mice (23.0 ± 0.9 g, 6 wk old) were randomly assigned into four groups (12 mice/group): control (C), intermittent fasting (F), melatonin (M), and intermittent fasting plus melatonin (MF). The C and M groups mice were provided with ad libitum access to food and water, while the F and MF groups underwent alternative-day feed deprivation (15 cycles total). Melatonin was administered in the drinking water of the M and MF groups. Blood, epididymal fat, liver tissue, and intestinal tissue and contents were collected for lab measurements, histology, and microbiota and metabolome analysis. Main effects and interactions were tested by 2-factor ANOVA. Results: IF significantly reduced BW gain and serum glucose, total cholesterol (TC) and triglyceride (TG) levels. Adipocyte size significantly decreased with IF, then the number of adipocytes per square millimeter significantly increased (P < 0.05). Compared to the C group, the M and MF groups had significantly higher serum melatonin levels (17 and 21%, respectively), although melatonin monotherapy had no effect on serum parameters and adipocytes. There was no interaction between IF and melatonin on BW gain and serum parameters except for on adipocyte area and number per square millimeter, Bacteroidetes and Akkermansia bacterial abundance, and the levels of the intestinal metabolites alanine, valine and isoleucine. IF changed the intestinal microbiota structure, with the F and MF groups clearly separating from the C and M groups. Metabolomic analysis showed that there was obvious separation between all four groups. Conclusions: IF, but neither melatonin nor the interaction between IF and melatonin, could alter intestinal microbiota and metabolism and prevent obesity by reducing BW gain, serum glucose, TC, and TG, and adipocyte size in mice.

Does intermittent fasting associated with aerobic training influence parameters related to the gut-brain axis of Wistar rats?

BACKGROUND

Intermittent fasting (IF) and aerobic training have demonstrated beneficial effects on intestinal microbiota composition, but little is known about benefits to the brain through the gut-brain axis. The present study aimed to evaluate gut-brain axis parameters in Wistar rats submitted to IF associated or not with aerobic training.

METHODS

Male rats were evaluated for training performance and then randomized into 4 groups of ten: sedentary control (SC), trained control (TC), sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF), and evaluated during four weeks.

RESULTS

The adiposity index was similar among the TC (2.15±0.43%), SIF (1.98±0.69%) and TIF (1.86±0.51%) groups, and differed from SC (2.98±0.80%). TIF had lower counts of lactic acid bacteria, while SIF had higher counts of Bifidobacterium and Enterococcus. TIF had the highest amount of formic acid in faeces (44.44±2.40 μmol/g) and lowest amount of succinic acid in the gut (0.38±0.00 μmol/g), while SIF had the highest propionic acid amount in the faeces (802.80±00.33 μmol/g) and the lowest amount of lactic acid in the gut (0.85±0.00 μmol/g). TIF demonstrated a tendency towards an anxiolytic effect and SIF showed potential antidepressant effect. IF caused different brain and intestinal injuries. TIF rats presented a diffuse and intense marking of IL-1β in the hippocampus.

CONCLUSION

IF and aerobic exercise, associated or not, can modulate parameters related to the gut-brain axis of Wistar rats, and some benefits may be related to the amounts of organic acids.

Loss of Sirt6 in adipocytes impairs the ability of adipose tissue to adapt to intermittent fasting

Intermittent fasting (IF) is gaining popularity for its effectiveness in improving overall health, including its effectiveness in achieving weight loss and euglycemia. The molecular mechanisms of IF, however, are not well understood. This study investigated the relationship between adipocyte sirtuin 6 (Sirt6) and the metabolic benefits of IF. Adipocyte-specific Sirt6-knockout (aS6KO) mice and wild-type littermates were fed a high-fat diet (HFD) ad libitum for four weeks and then subjected to 12 weeks on a 2:1 IF regimen consisting of two days of feeding followed by one day of fasting. Compared with wild-type mice, aS6KO mice subjected to HFD + IF exhibited a diminished response, as reflected by their glucose and insulin intolerance, reduced energy expenditure and adipose tissue browning, and increased inflammation of white adipose tissue. Sirt6 deficiency in hepatocytes or in myeloid cells did not impair adaptation to IF. Finally, the results indicated that the impaired adipose tissue browning and reduced expression of UCP1 in aS6KO mice were accompanied by downregulation of p38 MAPK/ATF2 signaling. Our findings indicate that Sirt6 in adipocytes is critical to obtaining the improved glucose metabolism and metabolic profiles conferred by IF and that maintaining high levels of Sirt6 in adipocytes may mimic the health benefits of IF.

Reversion to regular diet with alternate day fasting can cure grade-I non-alcoholic fatty liver disease (NAFLD) in high-fructose-intake-associated metabolic syndrome

Background

Non-alcoholic fatty liver disease (NAFLD) is an emerging global health problem that accompanied the obesity epidemic and is considered as the hepatic component of metabolic syndrome (MetS). Modification of lifestyle of MetS patients remains the focus to reverse and prevent progression of hepatic steatosis to NAFLD and its worsening to severe forms. The present study investigates the possible curability of metabolic syndrome -associated grade-1 NAFLD merely by alternate day fasting with or without reversion to regular diet in adult male rats. The present study was performed on 66 local strain male rats aged (6–10 m.) distributed randomly into C group (n = 12), on regular rat diet; and M group (n = 54) on high fructose- intake. On the 8th week, then rats were subjected to measurement of BW, BMI, WC, FBG, IPGTT, HDL-C, TGs, and liver histopathology, to include MetS rats randomly into four experimental groups for 4 weeks as follows: MS (n = 14); MSRD (n = 12); MSF (n = 13); and MSRDF (n = 12). On the 12th week, all rats were subjected to measurements of BW, BMI, WC, LW, LW/BW, VFW, VFW/BW, FBG, IPGTT, Ins., HOMA-IR, HbA1C, TGs, TC, LDL-C, HDL-C, CRP, Alb., bilirubin, ALT, L-MDA, and liver histopathology.

Results

On the 8th week, M group developed MerS and grade-I NAFLD with score-4 hepatosteatosis (69%). On the 12th week, MS group had grade-1 NAFLD with score-4 hepatosteatosis (82%) with significantly increased Ins., HOMA-IR, HDL-C, LW, LW/BW, L-MDA, ALT, CRP, and significantly decreased Alb. than C rats. Both MSRD and MSF groups had grade-1 NAFLD with score-3 hepatosteatosis (42%) with significantly decreased Ins., HOMA-IR, TC, LDL-C, LW, LW/BW, L-MDA, ALT, CRP, and significantly increased HDL-C and Alb. than MS group. MSRDF rats showed cure of grade-1 NAFLD and significantly decreased LW than other groups and normalized HOMA-IR, HbA1C TC, LDL-C, ALT, and CRP.

Conclusion

One month of alternate-day fasting and regular rat diet could cure grade-I NAFLD associated with Mets due to high fructose intake possibly by attenuating metabolic disorders. These two interventions might be recommended in the management of MetS patients with grade 1-NAFLD disease.

Intermittent fasting: from calories to time restriction

The global human population has recently experienced an increase in life expectancy with a mounting concern about the steady rise in the incidence of age-associated chronic diseases and socio-economic burden. Calorie restriction (CR), the reduction of energy intake without malnutrition, is a dietary manipulation that can increase health and longevity in most model organisms. However, the practice of CR in day-to-day life is a challenging long-term goal for human intervention. Recently, daily fasting length and periodicity have emerged as potential drivers behind CR's beneficial health effects. Numerous strategies and eating patterns have been successfully developed to recapitulate many of CR's benefits without its austerity. These novel feeding protocols range from shortened meal timing designed to interact with our circadian system (e.g., daily time-restricted feeding) to more extended fasting regimens known as intermittent fasting. Here, we provide a glimpse of the current status of knowledge on different strategies to reap the benefits of CR on metabolic health in murine models and in humans, without the rigor of continuous reduction in caloric intake as presented at the USU State of the Science Symposium.

Time-Restricted Eating, Intermittent Fasting, and Fasting-Mimicking Diets in Weight Loss

PURPOSE OF REVIEW

This article reviews the current literature on dietary interventions, including time-restricted eating (TRE), intermittent fasting (IF), and fasting-mimicking diets (FMD) and their effects on weight loss.

RECENT FINDINGS

Dietary interventions, primarily known for their potential health benefits, are attracting considerable interest also for their effects on weight loss. The literature suggests that many popular diets can induce weight loss but only a limited number of studies actually demonstrate long-term weight loss efficacy. Here we present an update on the latest studies on some of the most popular dietary interventions able to trigger the physiology of fasting and highlight their impact on weight loss in overweight or obese individuals.

Intermittent fasting ameliorates di-(2-ethylhexyl) phthalate-induced precocious puberty in female rats: A study of the hypothalamic-pituitary-gonadal axis

Di-(2-ethylhexyl) phthalate has been reported to interfere with the development and function of animal reproductive systems. However, hardly any studies provide methods to minimize or prevent the adverse effects of DEHP on reproduction. The energy balance state of mammals is closely related to reproductive activities, and the reproductive axis can regulate reproductive activities according to changes in the body's energy balance state. In this study, the effects of every other day fasting (EODF), as a way of intermittent fasting, on preventing the precocious puberty induced by DEHP in female rats was studied. EODF significantly improved the advancement of vaginal opening age (as the markers of puberty onset) and elevated serum levels of luteinizing hormone and estradiol (detected by ELISA) induced by 5 mg kg^-1 DEHP exposure (D5). The mRNA and western blot results showed that the EODF could minimized the increase of gonadotropin-releasing hormone expression induced by DEHP exposure. The administration of DEHP could elevate the levels of kisspeptin protein and the number of kisspeptin-immunoreactive neurons in anteroventral periventricular nucleu, and this increase was diminished considerably by EODF treatment. In contrast, the D5 and D0 groups showed no remarkable difference in the level of Kiss1 expression in arcuate nucleus, whereas the D5 + EODF group had a remarkable decrease in kisspeptin expression as compared with the other two groups. Our results indicated that EODF might inhibit the acceleration of puberty onset induced by DEHP exposure via HPG axis.

Health Effects of Alternate Day Fasting Versus Pair-Fed Caloric Restriction in Diet-Induced Obese C57Bl/6J Male Mice

Alternate day fasting (ADF) induces weight loss and improves various markers of health in rodents and humans. However, it is unclear whether the benefits of ADF are derived from the lower caloric intake of ADF or from the 24-h fasting period. Therefore, this study directly compared selected markers for health – such as glucose control, body weight, liver triglycerides, T cell frequencies, and others – in high-fat (60% calories from fat) diet-induced obese mice subjected to either ADF or caloric restriction (CR). Obese mice were randomly assigned to one of four groups: (1) ADF: remained on the high-fat diet, but fed on alternate days (n = 5), (2) PF: remained on the high-fat diet, but pair-fed to the ADF group (n = 5), (3) LF: moved to a chow ad libitum diet (n = 5; 17% calories from fat), and (4) HF: remained on the high-fat ad libitum diet (n = 5). An additional group of non-obese mice maintained on a chow diet since weaning were used as controls (CON: n = 5). After 10 weeks, ADF, PF, and LF mice ate fewer kcals, had a lower body mass, had smaller epididymal fat pads, improved glucose tolerance, and had a lower hepatic triglyceride content relative to HF mice (p < 0.05), but none reached that of CON mice in these measures. T cell frequencies of the spleen, blood, and mesenteric lymph nodes were reduced in ADF, PF, and HF compared to the CON group. Importantly, there were no significant differences between the ADF and PF groups in any of the measurements made in the current study. These data suggest that ADF, PF, and LF diets each lead to improved markers of health relative to high-fat diet-induced obese mice, and that the caloric restriction associated with ADF is the major factor for the noted improvements.

The role and its mechanism of intermittent fasting in tumors: friend or foe?

Intermittent fasting (IF) is becoming a prevailing topic worldwide, as it can cause changes in the body’s energy metabolism processes, improve health, and affect the progression of many diseases, particularly in the circumstance of oncology. Recent research has shown that IF can alter the energy metabolism of tumor cells, thereby inhibiting tumor growth and improving antitumor immune responses. Furthermore, IF can increase cancer sensitivity to chemotherapy and radiotherapy and reduce the side effects of these traditional anticancer treatments. IF is therefore emerging as a promising approach to clinical cancer treatment. However, the balance between long-term benefits of IF compared with the harm from insufficient caloric intake is not well understood. In this article, we review the role of IF in tumorigenesis and tumor therapy, and discuss some scientific problems that remain to be clarified, which might provide some assistance in the application of IF in clinical tumor therapy.

Intermittent fasting promotes anxiolytic-like effects unrelated to synaptic mitochondrial function and BDNF support

Anxiety disorders are linked to mitochondrial dysfunction and decreased neurotrophic support. Since anxiolytic drugs target mitochondria, non-pharmacological approaches to improve mitochondrial metabolism such as intermittent fasting (IF) may cause parallel behavioral benefits against anxiety disorders. Here, we investigated whether a chronic IF regimen could induce anxiolytic-like effects concomitantly to modulation in mitochondrial bioenergetics and trophic signaling in mice brain. A total of 44 Male C57BL/6 J mice (180 days old) were assigned to two dietary regimens: a normal, ad libitum diet (AL group) and an alternate-day fasting (IF group), where animals underwent 10 cycles of 24 h food restriction followed by 24 h ad libitum access. Animals underwent the open field test, dark/light box and elevated plus maze tasks. Isolated nerve terminals were obtained from mice brain and used for mitochondrial respirometry, hydrogen peroxide production and assessment of membrane potential dynamics, calcium handling and western blotting. We showed that IF significantly alters total daily food intake and food consumption patterns but not body weight. There were no differences in the exploratory and locomotory parameters. Remarkably, animals from IF showed decreased anxiety-like behavior. Mitochondrial metabolic responses in different coupling states and parameters linked with H₂O₂ production, Ca²⁺ buffering and electric gradient were not different between groups. Finally, no alterations in molecular indicators of apoptotic death (Bax/Bcl-2 ratio) and neuroplasticity (proBDNF/BDNF and synaptophysin were observed). In conclusion, IF exerts anxiolytic-like effect not associated with modulation in synaptic neuronergetics or expression of neurotrophic proteins. These results highlight a potential benefit of intermittent fasting as a nutritional intervention in anxiety-related disorders.

Pathophysiology linking depression and type 2 diabetes: Psychotherapy, physical exercise, and fecal microbiome transplantation as damage control

Diabetes increases the likelihood of developing depression and vice versa. Research on this bidirectional association has somewhat managed to delineate the interplay among implicated physiological processes. Still, further exploration is required in this context. This review addresses the comorbidity by investigating suspected common pathophysiological mechanisms. One such factor is psychological stress which disturbs the hypothalamic-pituitary-adrenal axis causing hormonal imbalance. This includes elevated cortisol levels, a common biomarker of both depression and diabetes. Disrupted insulin signaling drives the hampered neurotransmission of serotonin, dopamine, and norepinephrine. Also, adipokine hormones such as adiponectin, leptin, and resistin and the orexigenic hormone, ghrelin, are involved in both depression and T2DM. This disarray further interferes with physiological processes encompassing sleep, the gut-brain axis, metabolism, and mood stability. Behavioral coping mechanisms, such as unhealthy eating, mediate disturbed glucose homeostasis, and neuroinflammation. This is intricately linked to oxidative stress, redox imbalance, and mitochondrial dysfunction. However, interventions such as psychotherapy, physical exercise, fecal microbiota transplantation, and insulin-sensitizing agents can help to manage the distressing condition. The possibility of glucagon-like peptide 1 possessing a therapeutic role has also been discussed. Nonetheless, there stands an urgent need for unraveling new correlating targets and biological markers for efficient treatment.

Intermittent Fasting Improves Lipid Metabolism Through Changes in Gut Microbiota in Diet-Induced Obese Mice

Background

The mechanism of how intermittent fasting (IF) improves metabolism is not fully understood. Our study aimed to explore the effect of IF on lipid metabolism in obese mice, specifically on the intestinal flora.

Material/Methods

Diet-induced obese (DIO) mice were subjected to ad libitum (AL) feeding or IF (alternate-day fasting) for 30 days. We examined the lipid metabolism, fat distribution, gene expression of lipid metabolism, and intestinal flora in the mice.

Results

Despite having access to the same high-fat diet as the AL-fed groups, IF mice displayed pronounced weight loss, and their lipid metabolism significantly improved, mainly reflected in lower serum lipid levels and ameliorated liver steatosis. IF also reduced metabolic endotoxemia in DIO mice. The 16S ribosomal deoxyribonucleic acid gene amplicon sequencing suggested that IF did not change the community richness but had a tendency to increase community diversity in the intestinal flora. In addition, IF significantly reduced the ratio of Firmicutes to Bacteroidetes and increased the relative abundance of Allobaculum in the intestinal flora.

Conclusions

IF can improve fat metabolism, reduce fat accumulation, promote white fat conversion to beige, and improve gut microbiota.

Understanding Dietary Intervention-Mediated Epigenetic Modifications in Metabolic Diseases

The global prevalence of metabolic disorders, such as obesity, diabetes and fatty liver disease, is dramatically increasing. Both genetic and environmental factors are well-known contributors to the development of these diseases and therefore, the study of epigenetics can provide additional mechanistic insight. Dietary interventions, including caloric restriction, intermittent fasting or time-restricted feeding, have shown promising improvements in patients' overall metabolic profiles (i.e., reduced body weight, improved glucose homeostasis), and an increasing number of studies have associated these beneficial effects with epigenetic alterations. In this article, we review epigenetic changes involved in both metabolic diseases and dietary interventions in primary metabolic tissues (i.e., adipose, liver, and pancreas) in hopes of elucidating potential biomarkers and therapeutic targets for disease prevention and treatment.

Feeding behavior of growing and finishing pigs fed different dietary threonine levels in a group-phase feeding and individual precision feeding system

Feeding behavior is an important aspect of pig husbandry as it can affect protein deposition (PD) in pigs. A decrease in plasma threonine (Thr) levels may influence feed intake (FI) due to amino acid imbalance. We set out to study whether different Thr inclusion rates of 70%, 85%, 100%, 115%, and 130% of the ideal Thr:lysine (Lys) ratio of 0.65 in two different feeding programs (individual precision feeding and group-phase feeding could affect pig feeding behavior and consequently PD. Two 21-d trials were performed in a 2 × 5 factorial setup (feeding systems × Thr levels) with 110 pigs in the growing phase [25.0 ± 0.8 kg of body weight (BW)] and 110 pigs in the finishing phase (110.0 ± 7.0 kg BW), which correspond to 11 pigs per treatment in each trial. Pigs were housed in the same room and fed using computerized feeding stations. The total lean content was estimated by dual x-ray absorptiometry at the beginning (day 1) and the end (day 21) of the trial. Multivariate exploratory factor analysis was performed to identify related variables. Confirmatory analysis was performed by orthogonal contrasts and Pearson correlation analysis. Graphical analysis showed no difference in feeding patterns between feeding systems during the growing or finishing phase. Pigs exhibited a predominant diurnal feeding, with most meals (73% on average) consumed between 0600 and 1800 h. Exploratory factor analysis indicated that feeding behavior was not related to growth performance or PD in growing or finishing pigs. Changes in feeding behavior were observed during the growing phase, where increasing dietary Thr resulted in a linear increase in the FI rate (P < 0.05). During the finishing phase, the duration of the meal and FI rate increased linearly as dietary Thr increased in the diet (P < 0.05). These changes in feeding behavior are, however, correlated to BW. In conclusion, the exploratory factor analysis indicated that feeding behavior had no correlation with growth performance or protein and lipid deposition in growing or finishing pigs. Dietary Thr levels and feeding systems had no direct effect on FI.

Intermittent fasting ameliorates PM2.5 exposure-induced abnormalities in glycaemic control

Exposure to ambient fine particulate matter (PM_2.5) elicits various abnormalities in glycaemic control and thus correlates with type 2 diabetes. Intermittent fasting is an emerging treatment for type 2 diabetes. This study, therefore, tested whether intermittent fasting ameliorates PM_2.5 exposure-induced abnormalities in glycaemic control. To this end, C57Bl/6 J mice were exposed to filtered air (FA) or concentrated ambient PM_2.5 (CAP) for 16 weeks and concurrently subject to ad libitum feeding or intermittent fasting. The food intake assessment showed that CAP exposure transiently reduced food intake in ad libitum fed mice, but persistently reduced food intake in intermittently fasted mice. In contrast, CAP exposure persistently promoted mouse weight gain in ad libitum fed mice, while intermittent fasting blocked this CAP exposure-induced weight gain. The glucose homeostasis assessments revealed that CAP exposure elicited insulin resistance and glucose intolerance and meanwhile increased glucose-induced insulin secretion (GIIS). The insulin resistance and glucose intolerance, but not the increase in GIIS, induced by CAP exposure were blocked by intermittent fasting. Analysis of Akt phosphorylation, the indicator of local insulin signaling, showed that CAP exposure reduced insulin signaling in the liver and adipose tissues but not in the skeletal muscle. Intermittent fasting blocked CAP exposure-induced insulin resistance in the liver but not in the adipose tissues. The present study demonstrates that intermittent fasting ameliorates PM_2.5 exposure-induced insulin resistance and glucose intolerance, strongly supporting that it may be used to prevent type 2 diabetes due to exposure to PM_2.5.

Intermittent Fasting and High-Intensity Exercise Elicit Sexual-Dimorphic and Tissue-Specific Adaptations in Diet-Induced Obese Mice

The molecular adaptations that underpin body composition changes and health benefits of intermittent fasting (IF) and high-intensity interval training (HIIT) are unclear. The present study investigated these adaptations within the hypothalamus, white adipose and skeletal muscle tissue following 12 weeks of IF and/or HIIT in diet-induced obese mice. Mice (C57BL/6, 8-week-old, males/females) were fed high-fat (59%) and sugar (30%) water (HF/S) for 12 weeks followed by an additional 12 weeks of HF/S plus either IF, HIIT, combination (IF+HIIT) or HF/S only control (CON). Tissues were harvested at 12 and 24 weeks and analysed for various molecular markers. Hypothalamic NPY expression was significantly lower following IF+HIIT compared to CON in females. In adipose tissue, leptin expression was significantly lower following IF and IF+HIIT compared to CON in males and females. Males demonstrated increased markers of fat oxidation (HADH, FABP4) following IF+HIIT, whereas females demonstrated reduced markers of adipocyte differentiation/storage (CIDEC and FOXO1) following IF and/or IF+HIIT. In muscle, SIRT1, UCP3, PGC1α, and AS160 expression was significantly lower following IF compared to CON in males and/or females. This investigation suggests that males and females undertaking IF and HIIT may prevent weight gain via different mechanisms within the same tissue.

Intermittent fasting, adipokines, insulin sensitivity, and hypothalamic neuropeptides in a dietary overload with high-fat or high-fructose diet in mice

The intermittent fasting (IF) might have benefits on metabolism and food intake. Twelve-week old C57BL/6 J mice were fed a control diet (C, 10% kcal fat), a high-fat diet (HF, 50% kcal fat) or a high-fructose diet (HFru, 50% kcal fructose) for 8 weeks, then half of the animals in each group underwent IF (24 h fed, 24 h fasting) for an additional 4 weeks. Although food intake on the fed day remained the same for all groups, all fasting groups showed a reduction in body mass compared to their counterparts. IF reduced total cholesterol, triacylglycerol, fasting glucose, fasting insulin resistance index, and plasma leptin, but increased plasma adiponectin. IF reduced Leptin gene expression in the HF-IF group, but increased proinflammatory markers in the hypothalamus, also in the C-IF group. Both groups HFru-IF and C-IF, showed alterations in the leptin signaling pathway (Leptin, OBRb, and SOCS3), mainly in the HFru-IF group, suggesting leptin resistance. NPY and POMC neuropeptides labeled the neurons of the hypothalamus by immunofluorescence, corroborating qualitatively other quantitative findings of the study. In conclusion, current results are convincing in demonstrating the IF effect on central regulation of food intake control, as shown by NPY and POMC neuropeptide expressions, resulting in a lower weight gain. Besides, IF improves glycemia, lipid metabolism, and consequently insulin and leptin resistance. However, there is increased expression of inflammatory markers in mouse hypothalamus challenged by the HF and HFru diets, which in the long term may induce adverse effects.

Intermittent Fasting for Twelve Weeks Leads to Increases in Fat Mass and Hyperinsulinemia in Young Female Wistar Rats

Fasting is known to cause physiological changes in the endocrine pancreas, including decreased insulin secretion and increased reactive oxygen species (ROS) production. However, there is no consensus about the long-term effects of intermittent fasting (IF), which can involve up to 24 hours of fasting interspersed with normal feeding days. In the present study, we analyzed the effects of alternate-day IF for 12 weeks in a developing and healthy organism. Female 30-day-old Wistar rats were randomly divided into two groups: control, with free access to standard rodent chow; and IF, subjected to 24-hour fasts intercalated with 24-hours of free access to the same chow. Alternate-day IF decreased weight gain and food intake. Surprisingly, IF also elevated plasma insulin concentrations, both at baseline and after glucose administration collected during oGTT. After 12 weeks of dietary intervention, pancreatic islets displayed increased ROS production and apoptosis. Despite their lower body weight, IF animals had increased fat reserves and decreased muscle mass. Taken together, these findings suggest that alternate-day IF promote β -cell dysfunction, especially in developing animals. More long-term research is necessary to define the best IF protocol to reduce side effects.

Ketone production by ketogenic diet and by intermittent fasting has different effects on the gut microbiota and disease progression in an Alzheimer's disease rat model

The benefits of ketone production regimens remain controversial. Here, we hypothesized that the ketone-producing regimens modulated cognitive impairment, glucose metabolism, and inflammation while altering the gut microbiome. The hypothesis and the mechanism were explored in amyloid-β infused rats. Rats that received an amyloid-β(25–35) infusion into the hippocampus had either ketogenic diet (AD-KD), intermittent fasting (AD-IMF), 30 energy percent fat diet (AD-CON), or high carbohydrate (starch) diet (AD-CHO) for 8 weeks. AD-IMF and AD-CHO, but not AD-KD, lowered the hippocampal amyloid-β deposition compared to the AD-CON despite serum ketone concentrations being elevated in both AD-KD and AD-IMF. AD-IMF and AD-CHO, but not AD-KD, improved memory function in passive avoidance, Y maze, and water maze tests compared to the AD-CON. Hippocampal insulin signaling (pAkt→pGSK-3β) was potentiated and pTau was attenuated in AD-IMF and AD-CHO much more than AD-CON. AD-IMF and AD-CON had similar glucose tolerance results during OGTT, but AD-KD and AD-IMF exhibited glucose intolerance. AD-KD exacerbated gut dysbiosis by increasing Proteobacteria, and AD-CHO improved it by elevating Bacteriodetes. In conclusion, ketone production itself might not improve memory function, insulin resistance, neuroinflammation or the gut microbiome when induced by ketone-producing remedies. Intermittent fasting and a high carbohydrate diet containing high starch may be beneficial for people with dementia.

Intermittent fasting benefits on alpha- and beta-cell arrangement in diet-induced obese mice pancreatic islet

AIMS

There is a pancreatic islet adaptation in obese subjects, resulting in insulin resistance and diabetes type 2. We studied the effect of intermittent fasting (IntF) on the islet structure of diet-induced obese (DIO) mice.

METHODS

Three-month-old male mice fed a control diet (C, 10% Kcal fat) or a high-fat diet (HF, 50% Kcal fat) for two months (n = 20 each group). Then, half of each group did IntF (alternating 24 h fed/24 h fast), continuing in their diets four more weeks: C, C-IntF, HF, HF-IntF. Islets were prepared to microscopy or isolated for molecular analysis.

RESULTS

HF group (vs. C group) showed hyperglycemia, hyperinsulinemia, hyperleptinemia, hypoadiponectinemia, glucose intolerance, insulin resistance, and islet hypertrophy with a consequent higher both the alpha-cell and beta-cell masses. In the HF group (vs. C), there was low PDX1 (pancreatic and duodenal homeobox 1), and IntF did not alter PDX1. There was a low p-AKT/AKT ratio (protein kinase B), and IntF enhanced it. Also, tumor suppressor p53 was increased, and IntF decreased it. IL (interleukin) -6 was higher in the HF group (vs. C), and HF-IntF (vs. C-IntF). Any significant change in NFkB was seen among groups.

CONCLUSIONS

IntF improves pancreatic islet structure in DIO mice, even with continued HF diet intake, primarily considering on the alpha- and beta-cell masses regulation, then improving insulin signaling and decreasing cell apoptosis. Future research should explore whether the shortening of the IntF extend could maintain the benefits observed in the long term.

Molecular Mechanisms of Intermittent Fasting-induced Ischemic Tolerance

Diet is a significant factor in determining human well-being. Excessive eating and/or diets with higher than needed amounts of carbohydrates, salt, and fat are known to cause metabolic disorders and functional changes in the body. To compensate the ill effects, many designer diets including the Mediterranean diet, the Okinawa diet, vegetarian/vegan diets, keto diet, anti-inflammatory diet, and the anti-oxidant diet have been introduced in the past 2 decades. While these diets are either enriched or devoid of one or more specific components, a better way to control diet is to limit the amount of food consumed. Caloric restriction (CR), which involves limiting the amount of food consumed rather than eliminating any specific type of food, as well as intermittent fasting (IF), which entails limiting the time during which food can be consumed on a given day, have gained popularity because of their positive effects on human health. While the molecular mechanisms of these 2 dietary regimens have not been fully deciphered, they are known to prolong the life span, control blood pressure, and blood glucose levels. Furthermore, CR and IF were both shown to decrease the incidence of heart attack and stroke, as well as their ill effects. In particular, IF is thought to promote metabolic switching by altering gene expression profiles leading to reduced inflammation and oxidative stress, while increasing plasticity and regeneration.

Intermittent fasting: What questions should we be asking?

Obesity and overweight are contributing factors to chronic disease. Lifestyle management, which incorporates advice on moderate daily caloric restriction (CR) and physical activity to reduce body weight, is the cornerstone treatment in practice. Intermittent fasting (IF) is a popular alternative that cycles fasting with unrestricted eating periods. IF appears to be an equivalent approach to CR to induce weight loss, although as yet there is limited long-term evidence. Some controversy exists as to whether IF yields superior health benefits to CR. Discrepancies between studies may be due to the heterogeneity in the design of IF protocols. There is also still some concerns around the safety and feasibility of IF compared to CR, which has not been well-studied to date. Moreover, the underlying cellular pathways that are differentially activated in IF in comparison to CR requires further investigation in humans. This review summarises trials that have compared IF with CR, and discusses evidence from animal studies to raise questions for future research in humans.

Current nutritional and pharmacological anti-aging interventions

Aging is the main risk factor for chronic diseases and disablement in human societies with a great impact in social and health care expenditures. So far, aging and, eventually, death are unavoidable. Nevertheless, research efforts on aging-associated diseases with the aim not only to extend life span but also to increment health span in an attempt to delay, stop and even reverse the aging process have not stopped growing. Caloric restriction extends both health and life span in several short-lived experimental models and has brought to light the role of different molecular effectors involved in nutrient sensing pathways and longevity. This opens the possibility of modulating these molecular effectors also in humans to increase longevity and health span. The difficulty to implement caloric restricted diets in humans has led to the development of new bearable diets such as time-restricted feeding, intermittent fasting or diets with limited amounts of some nutrients and to the search of pharmacological agents, targeted to the effectors that mediate the extension of life and health span in response to these anti-aging diets. Pharmacological approaches that eliminate senescent cells or prevent primary causes of aging such as telomere attrition also emerge as potential anti-aging strategies. In the present article, we review these possible nutritional and pharmacological interventions designed to mitigate and/or delay the aging process and to increase health and life span.