Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study

Obesity and Weight Loss Strategies for Patients With Heart Failure

Obesity is a common comorbidity among patients with heart failure with reduced ejection fraction (HFrEF) or heart failure with preserved ejection fraction (HFpEF), with the strongest pathophysiologic link of obesity being seen for HFpEF. Lifestyle measures are the cornerstone of weight loss management, but sustainability is a challenge, and there are limited efficacy data in the heart failure (HF) population. Bariatric surgery has moderate efficacy and safety data for patients with preoperative HF or left ventricular dysfunction and has been associated with reductions in HF hospitalizations and medium-term mortality. Antiobesity medications historically carried concerns for cardiovascular adverse effects, but the safety and weight loss efficacy seen in general population trials of glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide/GLP-1 agonists are highly encouraging. Although there are safety concerns regarding GLP-1 agonists in advanced HFrEF, trials of the GLP-1 agonist semaglutide for treatment of obesity have confirmed safety and efficacy in patients with HFpEF.

Time-restricted eating affects human adipose tissue fat mobilization

OBJECTIVE

Time-restricted eating (TRE), a dietary approach that confines food intake to specific time windows, has shown metabolic benefits. However, its impact on body weight loss remains inconclusive. The objective of this study was to investigate the influence of early TRE (eTRE) and delayed TRE (dTRE) on fat mobilization using human adipose tissue (AT) cultures.

METHODS

Subcutaneous AT was collected from 21 participants with severe obesity. We assessed fat mobilization by measuring glycerol release in AT culture across four treatment conditions: control, eTRE, dTRE, and 24-h fasting.

RESULTS

TRE had a significant impact on lipolysis (glycerol release [mean (SD)] in micromoles per hour per gram: control, 0.05 [0.003]; eTRE, 0.10 [0.006]; dTRE, 0.08 [0.005]; and fasting, 0.17 [0.008]; p < 0.0001). Both eTRE and dTRE increased lipolysis compared with the control group, with eTRE showing higher glycerol mobilization than dTRE during the overall 24-h time window, especially at the nighttime/habitual sleep episode (p < 0.0001). Further analysis of TRE based on fasting duration revealed that, independently of the time window, glycerol release increased with fasting duration (in micromoles per hour per gram: 8 h = 0.08 [0.001]; 12 h = 0.09 [0.008]; and 16 h of fasting = 0.12 [0.011]; p < 0.0001).

CONCLUSIONS

This study provides insights into the potential benefits of TRE on fat mobilization and may guide the design of future dietary strategies for weight management and metabolic health.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

Among 104,420 mostly female (78.5%) participants aged 52.7 ± 9.5 (standard deviation) y followed for 6 y, a 1-h increase in ONF length was associated with a small but statistically significant reduction in weight gain over 3- and 6-y periods [multivariable-adjusted mean difference in % body weight = -0.02, 95% confidence interval (CI): -0.05, -0.00, P = 0.03 and -0.04, 95% CI: -0.07, -0.01, P = 0.007, respectively]. The mean difference of 6-y % reduction in weight gain was slightly greater among individuals with overweight (-0.05, 95% CI: -0.10, 0.00, P = 0.05) and obesity (-0.06, 95% CI: -0.12, 0.01, P = 0.08) compared with those with healthy body mass index (-0.03, 95% CI:-0.07, 0.01, P = 0.13) or underweight (0.16, 95% CI: -0.04, 0.36, P = 0.13, Pinteraction < 0.0001). Stronger associations were observed among those ≤55 y than 56+ (Pinteraction = 0.01), and those with higher waist circumference (Pinteraction < 0.0001) but not by sex or earlier/later fasting period.

CONCLUSIONS

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

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

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

Unraveling the Health Benefits and Mechanisms of Time-Restricted Feeding: Beyond Caloric Restriction

Time-restricted feeding (TRF) is a lifestyle intervention that aims to maintain a consistent daily cycle of feeding and fasting to support robust circadian rhythms. Recently, it has gained scientific, medical, and public attention due to its potential to enhance body composition, extend lifespan, and improve overall health, as well as induce autophagy and alleviate symptoms of diseases like cardiovascular diseases, type 2 diabetes, neurodegenerative diseases, cancer, and ischemic injury. However, there is still considerable debate on the primary factors that contribute to the health benefits of TRF. Despite not imposing strict limitations on calorie intake, TRF consistently led to reductions in calorie intake. Therefore, while some studies suggest that the health benefits of TRF are primarily due to caloric restriction (CR), others argue that the key advantages of TRF arise not only from CR but also from factors like the duration of fasting, the timing of the feeding period, and alignment with circadian rhythms. To elucidate the roles and mechanisms of TRF beyond CR, this review incorporates TRF studies that did not use CR, as well as TRF studies with equivalent energy intake to CR, which addresses the previous lack of comprehensive research on TRF without CR and provides a framework for future research directions.

Intermittent Fasting in Youth: A Scoping Review

Intermittent fasting (IF) focuses on the timing of eating rather than diet quality or energy intake, with evidence supporting its effects on weight loss and cardiometabolic outcomes in adults. However, there is limited evidence for its efficacy in adolescents and emerging adults. To address this, a scoping review examined IF regimens in individuals aged 10 to 25, focusing on methodology, intervention parameters, outcomes, adherence, feasibility, and efficacy. The review included 39 studies with 731 participants aged 15 to 25. Methodologies varied, with 18 studies on time-restricted eating and others requiring caloric restriction. Primary outcomes included cardiometabolic risk factors (11/29), body composition (9/29), anthropometric measurements (8/29), and feasibility (2/29). Most studies reported significant weight loss. This review underscores IF's potential in treating obesity in this age group but highlights the need for rigorous studies with standardized frameworks for feasibility to ensure comparability and determine IF's practicality in this age group.

Macrophage-derived chemokine CCL22 establishes local LN-mediated adaptive thermogenesis and energy expenditure

There is a regional preference around lymph nodes (LNs) for adipose beiging. Here, we show that local LN removal within inguinal white adipose tissue (iWAT) greatly impairs cold-induced beiging, and this impairment can be restored by injecting M2 macrophages or macrophage-derived C-C motif chemokine (CCL22) into iWAT. CCL22 injection into iWAT effectively promotes iWAT beiging, while blocking CCL22 with antibodies can prevent it. Mechanistically, the CCL22 receptor, C-C motif chemokine receptor 4 (CCR4), within eosinophils and its downstream focal adhesion kinase/p65/interleukin-4 signaling are essential for CCL22-mediated beige adipocyte formation. Moreover, CCL22 levels are inversely correlated with body weight and fat mass in mice and humans. Acute elevation of CCL22 levels effectively prevents diet-induced body weight and fat gain by enhancing adipose beiging. Together, our data identify the CCL22-CCR4 axis as an essential mediator for LN-controlled adaptive thermogenesis and highlight its potential to combat obesity and its associated complications.

Intermittent Fasting: Myths, Fakes and Truth on This Dietary Regimen Approach

Intermittent fasting (IF) has been indicated as a valuable alternative to the classical caloric restriction dietary regimen for lowering body weight and preventing obesity-related complications, such as metabolic syndrome and type II diabetes. However, is it effective? In this review article, we analyzed over 50 clinical studies in which IF, conducted by alternate day fasting (ADF) or time-restricted feeding (TRF), was compared with the caloric restriction approach. We evaluated the different roles of IF in treating and preventing human disorders such as metabolic syndrome, type II diabetes, and some types of cancer, as well as the usefulness of IF in reducing body weight and cardiovascular risk factors such as hypertension. Furthermore, we explored the cellular pathways targeted by IF to exert their beneficial effects by activating effector proteins that modulate cell functions and resistance to oxidative stress. In contrast, we investigated concerns regarding human health related to the adoption of IF dietary regimens, highlighting the profound debate surrounding weight loss regimens. We examined and compared several clinical trials to formulate an updated concept regarding IF and its therapeutic potential.

Feasibility and Cardiometabolic Effects of Time-Restricted Eating in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) and a prolonged daily eating window (EW) are associated with circadian rhythm disruption and increased cardiometabolic risk. Misalignment between circadian timing system and daily rhythms of food intake adversely impacts metabolic regulatory mechanisms and cardiovascular function. Restricting the daily EW by imposing an eating-fasting cycle through time-restricted eating (TRE) can restore robust circadian rhythms, support cellular metabolism, and improve cardiometabolic health. The aim of this study was to assess a feasibility of 12-week TRE intervention with self-selected 10 h EW and effects of TRE on EW duration, cardiometabolic outcomes, daily rhythms of behavior, and wellbeing in Polish patients with MetS and EW ≥ 14 h/day. Dietary intake was monitored with a validated myCircadianClock application (mCC app). Adherence to TRE defined as the proportion of days recorded with mCC app in which participants satisfied 10-h TRE was the primary outcome. A total of 26 patients (aged 45 ± 13 years, 62% women, 3.3 ± 0.5 MetS criteria, EW 14 ± 1.5 h/day) were enrolled. Coexistence of increased waist circumference (WC) (96% of patients), elevated fasting plasma glucose (FPG) (77%), and elevated blood pressure (BP) (69%) was the most common MetS pattern (50%). TRE intervention (mean duration of 81.6 ± 12.6 days) led to reducing daily EW by 28% (p < 0.0001). Adherence to TRE was 87 ± 13%. Adherence to logging food intake on mCC app during TRE was 70 ± 27%. Post TRE, a decrease in body weight (2%, 1.7 ± 3.6 kg, p = 0.026), body mass index (BMI) (1%, 0.5 ± 1.2 kg/m2, p = 0.027), WC (2%, 2.5 ± 3.9 cm, p = 0.003), systolic BP (4%, 4.8 ± 9.0 mmHg, p = 0.012), FPG (4%, 3.8 ± 6.9 mg/dL, p = 0.037), glycated hemoglobin (4%, 0.2 ± 0.4%, p = 0.011), mean fasting glucose level from continuous glucose monitor (CGM) (4%, 4.0 ± 6.1 mg/dL, p = 0.002), and sleepiness score (25%, 1.9 ± 3.2 points, p = 0043) were observed. A significant decrease in body weight (2%), BMI (2%), WC (3%), mean CGM fasting glucose (6%), sleepiness score (27%), and depression score (60%) was found in patients with mean post-TRE EW ≤ 10 h/day (58% of total), and not in patients with EW > 10 h/day. Adherence to TRE was higher in patients with post-TRE EW ≤ 10 h/day vs. patients with EW > 10 h/day (94 ± 6% vs. 77 ± 14%, p = 0.003). Our findings indicate that 10-h TRE was feasible in the European MetS population. TRE resulted in reducing daily EW and improved cardiometabolic outcomes and wellbeing in patients with MetS and prolonged EW. Use of the mCC app can aid in implementing TRE. This pilot clinical trial provides exploratory data that are a basis for a large-scale randomized controlled trial to determine the efficacy and sustainability of TRE for reducing cardiometabolic risks in MetS populations. Further research is needed to investigate the mechanisms of TRE effects, including its impact on circadian rhythm disruption.

Effect of time restricted feeding on anthropometric measures, eating behavior, stress, serum levels of BDNF and LBP in overweight/obese women with food addiction: a randomized clinical trial

BACKGROUND & AIM

Food addiction (FA) as a specific food-related behavior may play an essential role in the pathogenesis of obesity. Brain-derived neurotrophic factor (BDNF) and gut microbiota (GM) alterations probably through fasting are closely related to brain function, affecting eating behaviors and body weight management. This study aimed to evaluate the effect of time-restricted feeding (TRF) on serum BDNF levels and eating behaviors in overweight and obese women with FA.

METHODS AND DESIGN

This clinical trial was performed with a 2-month follow-up on 56 obese and overweight women with FA. Participants were randomly divided into two groups receiving a low-calorie diet (n = 27) and a group receiving a low-calorie diet with TRF (n = 29). Anthropometric measurements, biochemical markers, eating behavior, and stress were assessed during the study period.

RESULTS

The reductions in weight, body mass index (BMI), waist circumference, and body fat mass were significantly higher in the TRF group compared to the control group at week 8 (P = 0.018, P = 0.015. P = 0.03, and P = 0.036, respectively). The cognitive restriction score was higher in the TRF as compared with the control group (P = 0.002). The food addiction criteria score was significantly reduced in both groups (P < 0.001). Serum levels of BDNF were significantly increased in the TRF group (P < 0.001). In addition, BDNF levels had a positive and significant correlation with the cognitive restriction score (r = 0.468 and P < 0.001), While the correlation with FA was not significant (β = 0.588 and P = 0.618). Lipopolysaccharide binding protein decreased significantly in both groups, but this decrease was significantly higher in the TRF group than in the control group (P < 0.001).

CONCLUSION

The results of this study showed that a low-calorie diet with TRF is more effective in weight management than a low-calorie diet alone, probably through further modulating the GM and improving BDNF levels. More effective weight loss in the TRF is probably related to better management of eating behavior than FA.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials identifier: IRCT20131228015968N7.

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.

Effects of Early and Late Time-Restricted Feeding on Parameters of Metabolic Health: An Explorative Literature Assessment

Chrono-nutrition (meal timing) aligns food consumption with one's circadian rhythm. The first meal (e.g., breakfast) likely promotes synchronization of peripheral circadian clocks, thereby supporting metabolic health. Time-restricted feeding (TRF) has been shown to reduce body weight (BW) and/or improve cardiovascular biomarkers. In this explorative literature assessment, 13 TRF randomized controlled trials (RCTs) were selected from PubMed and Scopus to evaluate the effects of early (eTRF: first meal before 10:30 a.m.) and late TRF (lTRF: first meal after 11:30 a.m.) on parameters of metabolic health. Although distinct variations in study design were evident between reports, TRF consistently decreased energy intake (EI) and BW, and improved insulin resistance as well as systolic blood pressure. eTRF seemed to have a greater beneficial effect than lTRF on insulin resistance (HOMA-IR). Importantly, most studies did not appear to consider chronotype in their evaluation, which may have underestimated TRF effects. TRF intervention may be a promising approach for risk reduction of human metabolic diseases. To conclusively determine benefits of TRF and identify clear differences between eTRF and lTRF, future studies should be longer-term (≥8 weeks) with well-defined (differences in) feeding windows, include participants chronotypically matching the intervention, and compare outcomes to those of control groups without any dietary limitations.

Unlocking the power of synergy: High-intensity functional training and early time-restricted eating for transformative changes in body composition and cardiometabolic health in inactive women with obesity

OBJECTIVE

The purpose of this study was to examine the long-term effects of time-restricted eating (TRE), with or without high intensity functional training (HIFT), on body composition and cardiometabolic biomarkers among inactive women with obesity.

METHODS

Sixty-four women (BMI = 35.03 ± 3.8 kg/m2; age = 32.1 ± 10 years) were randomly allocated to either: (1) TRE (≤8-h daily eating window, with ad libitum energy intake) group; (2) HIFT (3 sessions/week) group; or (3) TRE combined with HIFT (TRE-HIFT) group. The interventions lasted 12 weeks with a pre-post measurement design. A HIFT session consists of 8 sets of multiple functional exercises with self-selected intensity (20 or 30s work/10s rest).

RESULTS

TRE-HIFT showed a greater decrease of waist and hip circumferences and fat mass compared to TRE (p = 0.02, p = 0.02 and p<0.01; respectively) and HIFT (p = 0.012, p = 0.028 and p<0.001; respectively). Weight and BMI decreased in TRE-HIFT compared to HIFT group (p<0.001; for both). Fat-free mass was lower in TRE compared to both HIFT and TRE-HIFT groups (p<0.01 and p<0.001; respectively). Total cholesterol, triglyceride, insulin, and HOMA-IR decreased in TRE-HIFT compared to both TRE (p<0.001, p<0.01, p = 0.015 and p<0.01; respectively) and HIFT (p<0.001, p = 0.02, p<0.01 and p<0.001; respectively) groups. Glucose level decreased in TRE-HIFT compared to HIFT (p<0.01). Systolic blood pressure decreased significantly in both TRE-HIFT and HIFT groups compared to TRE group (p = 0.04 and p = 0.02; respectively).

CONCLUSION

In inactive women with obesity, combining TRE with HIFT can be a good strategy to induce superior effects on body composition, lipid profile and glucose regulation compared with either diet or exercise intervention alone.

TRIAL REGISTRATION

Clinical Trials Number: PACTR202301674821174.

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.

Circadian alignment of food intake and glycaemic control by time-restricted eating: A systematic review and meta-analysis

Daily rhythms of metabolic function are supported by molecular circadian clock systems that are strongly regulated by feeding and fasting. Intermittent fasting diets have been associated with weight loss and improved metabolism. However, the effects of time-restricted eating (TRE) on glycemic parameters are still under debate. In this review, we aim to systematically analyze the effects of TRE on glycemic parameters. We searched on PubMed, EMBASE, and the Cochrane Library for controlled studies in which subjects followed TRE for at least 4 weeks. 20 studies were included in the qualitative systematic review, and 18 studies (n = 1169 subjects) were included in the meta-analysis. Overall, TRE had no significant effect on fasting glucose (Hedges's g = -0.08; 95% CI:-0.31,0.16; p = 0.52), but it did reduce HbA1c levels (Hedges's g = -0.27; 95% CI: -0.47, -0.06; p = 0.01). TRE significantly reduced fasting insulin (Hedges's g = -0.40; 95% CI: -0.73,-0.08; p = 0.01) and showed a tendency to decrease HOMA-IR (Hedges's g = -0.32; 95% CI:-0.66,0.02; p = 0.06). Interestingly, a cumulative analysis showed that the beneficial effects of TRE regarding glucose levels were less apparent as studies with later TRE windows (lTRE) were being included. Indeed, a subgroup analysis of the early TRE (eTRE) studies revealed that fasting glucose was significantly reduced by eTRE (Hedges's g = -0.38; 95% CI:-0.62, -0.14; p < 0.01). Our meta-analysis suggests that TRE can reduce HbA1c and insulin levels, and that timing of food intake is a crucial factor in the metabolic benefit of TRE, as only eTRE is capable of reducing fasting glucose levels in subjects with overweight or obesity.PROSPERO registration number CRD42023405946.

Conceptualization and Assessment of 24-H Timing of Eating and Energy Intake: A Methodological Systematic Review of the Chronic Disease Literature

Timing of eating (TOE) and energy intake (TOEI) has important implications for chronic disease risk beyond diet quality. The 2020 Dietary Guidelines Advisory Committee recommended developing consistent terminology to address the lack of TOE/TOEI standardization. The primary objective of this methodological systematic review was to characterize the conceptualization and assessment of TOE/TOEI within the chronic disease literature (International Prospective Register of Systematic Reviews registration number: CRD42021236621). Literature searches in Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus, Embase, PubMed, and Scopus were limited to English language publications from 2000 to August 2022. Eligible studies reported the association between TOE/TOEI and obesity, cardiovascular disease, type 2 diabetes mellitus, cancer, or a related clinical risk factor among adults (≥19 y) in observational and intervention studies. A qualitative synthesis described and compared TOE/TOEI conceptualization, definitions, and assessment methods across studies. Of the 7579 unique publications identified, 259 studies (observational [51.4 %], intervention [47.5 %], or both [1.2 %]) were eligible for inclusion. Key findings indicated that most studies (49.6 %) were conducted in the context of obesity and body weight. TOE/TOEI variables or assigned conditions conceptualized interrelated aspects of time and eating or energy intake in varying ways. Common TOE/TOEI conceptualizations included the following: 1) timepoint (specific time to represent when intake occurs, such as time of breakfast [74.8 %]); 2) duration (length of time or interval when intake does/does not occur, such as "eating window" [56.5 %]); 3) distribution (proportion of daily intake at a given time interval, such as "percentage of energy before noon" [29.8 %]); and 4) cluster (grouping individuals based on temporal ingestive characteristics [5.0 %]). Assessment, definition, and operationalization of 24-h TOE/TOEI variables varied widely across studies. Observational studies most often used surveys or questionnaires (28.9 %), whereas interventions used virtual or in-person meetings (23.8 %) to assess TOE/TOEI adherence. Overall, the diversity of terminology and methods solidifies the need for standardization to guide future research in chrononutrition and to facilitate inter-study comparisons.

Effect of Aerobic Exercise and Time-Restricted Feeding on Metabolic Markers and Circadian Rhythm in Mice Fed with the High-Fat Diet

SCOPE

Diet and exercise are significant players in obesity and metabolic diseases. Time-restricted feeding (tRF) has been shown to improve metabolic responses by regulating circadian clocks but whether it acts synergically with exercise remains unknown. It is hypothesized that forced exercise alone or combined with tRF alleviates obesity and its metabolic complications.

METHODS AND RESULTS

Male C57bl6 mice are fed with high-fat or a control diet for 12 weeks either ad libitum or tRF for 10 h during their active period. High-fat diet (HFD)-fed mice are divided into exercise (treadmill for 1 h at 12 m min-1 alternate days for 9 weeks and 16 m min-1 daily for the following 3 weeks) and non-exercise groups. tRF and tRF-Ex significantly decreased body weight, food intake, and plasma lipids, and improved glucose tolerance. However, exercise reduced only body weight and plasma lipids. tRF and tRF-Ex significantly downregulated Fasn, Hmgcr, and Srebp1c, while exercise only Hmgcr. HFD feeding disrupted clock genes, but exercise, tRF, and tRF-Ex coordinated the circadian clock genes Bmal1, Per2, and Rev-Erbα in the liver, adipose tissue, and skeletal muscles.

CONCLUSION

HFD feeding disrupted clock genes in the peripheral organs while exercise, tRF, and their combination restored clock genes and improved metabolic consequences induced by high-fat diet feeding.

Chronomedicine Insights: Evaluating the Impact of Time-Restricted Meal Intake on Lipid Profile Parameters Among Individuals With Type 2 Diabetes in Northern India

INTRODUCTION

Time-restricted meal intake (TRM) has shown potential benefits such as enhanced insulin sensitivity, lowered blood sugar levels, and possible weight loss in individuals with type 2 diabetes mellitus (T2DM). Our study aimed to investigate the impact of TRM on lipid profile parameters such as total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in fasting conditions in T2DM patients.

METHODS

In total, 400 patients from the endocrinology department at King George's Medical University (KGMU), Lucknow were enrolled in this study, adhering to the guidelines of the American Diabetes Association (ADA). Male and female patients with recently diagnosed T2DM (in the past five years), aged between 25 to 60 years, on oral anti-diabetic therapy excluding insulin, expressing willingness to provide written consent and to adhere to TRM were included in the TRM group. It was a longitudinal study as diabetic dyslipidemia is primarily caused by insulin resistance and nutritional reasons and we wanted to assess the effect of TRM on lipid profile in T2DM patients. Patients were enrolled via simple random sampling using the random number table method (computerized). The TRM group had an early dinner at 7 pm whereas the control group was of non-TRM/late-night eaters. TRM group was given comprehensive guidance including strategies to manage hunger, permissible beverage options (water and prescribed medication) during the fasting period, and daily maintenance of a diary documenting their timing, type, and quantity of food intake which they were requested to bring fortnightly. Emphasis was placed on recording even minor dietary items consumed throughout the day. The TRM group consumed food ad libitum during a 12-hour eating window from breakfast at 7 am to dinner at 7 pm. Data distribution was non-parametric. Mann-Whitney U test compared TRM and control group using mean values at baseline and follow-ups. Analysis used GraphPad Prism 9.2.0 software (GraphPad Inc., La Jolla, CA). A p-value less than 0.05 (p < 0.05) was considered statistically significant.

RESULTS

A total of 127 patients were lost to follow-up, resulting in 273 patients who completed the study. The mean value of TC in the TRM and non-TRM groups using the Mann-Whitney U test registered a highly significant p-value <0.0001 at 18 months, with a decrease of 14.17% from baseline in the TRM group and a decrease of 1.53% from baseline in the non-TRM group. The TRM group had a decrease of 24.75% in TG from a baseline value of 145.4±41.9, whereas the non-TRM group showed a decrease of 2.2% from a baseline value of 154.7±37.30 (p-value <0.0001). The TRM group showed an increase of 9.25% in HDL from a baseline value of 50.14±8.58; the non-TRM group showed an increase of 0.82% from a baseline value of 48.62±9.31 (p-value <0.0001). TRM group showed a decrease of 8.62% in LDL from a baseline value of 68.20±16.2 while the non-TRM group showed an increase of 1.54% from a baseline value of 65.38±19.3 (p-value <0.0002). The TRM group showed a decrease of 13.97% in VLDL from a baseline value of 32.20±18.7; the non-TRM group showed an increase of 4% from a baseline value of 30.16±24.2 (p-value <0.0001).

CONCLUSION

Our study's promising results underscore the potential of TRM as an effective strategy for managing dyslipidemia in individuals with T2DM, even over prolonged periods.

Dietary approaches for exploiting metabolic vulnerabilities in cancer

Renewed interest in tumor metabolism sparked an enthusiasm for dietary interventions to prevent and treat cancer. Changes in diet impact circulating nutrient levels in the plasma and the tumor microenvironment, and preclinical studies suggest that dietary approaches, including caloric and nutrient restrictions, can modulate tumor initiation, progression, and metastasis. Cancers are heterogeneous in their metabolic dependencies and preferred energy sources and can be addicted to glucose, fructose, amino acids, or lipids for survival and growth. This dependence is influenced by tumor type, anatomical location, tissue of origin, aberrant signaling, and the microenvironment. This review summarizes nutrient dependencies and the related signaling pathway activations that provide targets for nutritional interventions. We examine popular dietary approaches used as adjuvants to anticancer therapies, encompassing caloric restrictions, including time-restricted feeding, intermittent fasting, fasting-mimicking diets (FMDs), and nutrient restrictions, notably the ketogenic diet. Despite promising results, much of the knowledge on dietary restrictions comes from in vitro and animal studies, which may not accurately reflect real-life situations. Further research is needed to determine the optimal duration, timing, safety, and efficacy of dietary restrictions for different cancers and treatments. In addition, well-designed human trials are necessary to establish the link between specific metabolic vulnerabilities and targeted dietary interventions. However, low patient compliance in clinical trials remains a significant challenge.

Time-restricted eating improves health because of energy deficit and circadian rhythm: A systematic review and meta-analysis

Time-restricted eating (TRE) is an effective way to lose weight and improve metabolic health in animals. Yet whether and how these benefits apply to humans is unclear. This systematic review and meta-analysis examined the effect of TRE in people with overweight and obesity statuses. The results showed that TRE led to modest weight loss, lower waist circumference and energy deficits. TRE also improved body mass index, fat mass, lean body mass, systolic blood pressure, fasting glucose levels, fasting insulin levels, and HbA1c%. Subgroup analysis demonstrated more health improvements in the TRE group than the control group under the ad libitum intake condition than in the energy-prescribed condition. Eating time-of-day advantages were only seen when there was considerable energy reduction in the TRE group than the control group (ad libitum condition), implying that the benefits of TRE were primarily due to energy deficit, followed by alignment with eating time of day.

Circadian Regulation of Endocrine Fibroblast Growth Factors on Systemic Energy Metabolism

The circadian clock is an endogenous biochemical timing system that coordinates the physiology and behavior of organisms to earth's ∼24-hour circadian day/night cycle. The central circadian clock synchronized by environmental cues hierarchically entrains peripheral clocks throughout the body. The circadian system modulates a wide variety of metabolic signaling pathways to maintain whole-body metabolic homeostasis in mammals under changing environmental conditions. Endocrine fibroblast growth factors (FGFs), namely FGF15/19, FGF21, and FGF23, play an important role in regulating systemic metabolism of bile acids, lipids, glucose, proteins, and minerals. Recent evidence indicates that endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between peripheral clocks and energy homeostasis by regulating the expression of metabolic enzymes and hormones. Circadian disruption induced by environmental stressors or genetic ablation is associated with metabolic dysfunction and diurnal disturbances in FGF signaling pathways that contribute to the pathogenesis of metabolic diseases. Time-restricted feeding strengthens the circadian pattern of metabolic signals to improve metabolic health and prevent against metabolic diseases. Chronotherapy, the strategic timing of medication administration to maximize beneficial effects and minimize toxic effects, can provide novel insights into linking biologic rhythms to drug metabolism and toxicity within the therapeutical regimens of diseases. Here we review the circadian regulation of endocrine FGF signaling in whole-body metabolism and the potential effect of circadian dysfunction on the pathogenesis and development of metabolic diseases. We also discuss the potential of chrononutrition and chronotherapy for informing the development of timing interventions with endocrine FGFs to optimize whole-body metabolism in humans. SIGNIFICANCE STATEMENT: The circadian timing system governs physiological, metabolic, and behavioral functions in living organisms. The endocrine fibroblast growth factor (FGF) family (FGF15/19, FGF21, and FGF23) plays an important role in regulating energy and mineral metabolism. Endocrine FGFs function as nutrient sensors that mediate multifactorial interactions between circadian clocks and metabolic homeostasis. Chronic disruption of circadian rhythms increases the risk of metabolic diseases. Chronological interventions such as chrononutrition and chronotherapy provide insights into linking biological rhythms to disease prevention and treatment.

Time-restricted feeding restores metabolic flexibility in adult mice with excess adiposity

Introduction

Obesity is prevalent with the adult population in the United States. Energy-dense diets and erratic eating behavior contribute to obesity. Time-restricted eating is a dietary strategy in humans that has been advanced to reduce the propensity for obesity. We hypothesized that time-restricted feeding (TRF) would improve metabolic flexibility and normalize metabolic function in adult mice with established excess adiposity.

Methods

Male C57BL/6NHsd mice were initially fed a high-fat diet (HFD) for 12 weeks to establish excess body adiposity, while control mice were fed a normal diet. Then, the HFD-fed mice were assigned to two groups, either ad libitum HFD or TRF of the HFD in the dark phase (12 h) for another 12 weeks.

Results and discussion

Energy intake and body fat mass were similar in TRF and HFD-fed mice. TRF restored rhythmic oscillations of respiratory exchange ratio (RER), which had been flattened by the HFD, with greater RER amplitude in the dark phase. Insulin sensitivity was improved and plasma cholesterol and hepatic triacylglycerol were decreased by TRF. When compared to HFD, TRF decreased transcription of circadian genes Per1 and Per2 and genes encoding lipid metabolism (Acaca, Fads1, Fads2, Fasn, Scd1, and Srebf1) in liver. Metabolomic analysis showed that TRF created a profile that was distinct from those of mice fed the control diet or HFD, particularly in altered amino acid profiles. These included aminoacyl-tRNA-biosynthesis, glutathione metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis pathways. In conclusion, TRF improved metabolic function in adult mice with excess adiposity. This improvement was not through a reduction in body fat mass but through the restoration of metabolic flexibility.

The impact of intermittent fasting on gut microbiota: a systematic review of human studies

Background

Intermittent fasting (IF) has gained popularity in interventions targeting overweight, obesity and metabolic syndrome. IF may affect the gut microbiome composition and therefore have various effects on gut microbiome mediated functions in humans. Research on the effects of IF on human gut microbiome is limited. Therefore, the objective of this systematic review was to determine how different types of IF affect the human gut microbiome.

Methods

A literature search was conducted for studies investigating the association of different types of IF and gut microbiota richness, alpha and beta diversity, and composition in human subjects. Databases included Cochrane Library (RRID:SCR_013000), PubMed (RRID:SCR_004846), Scopus (RRID:SCR_022559) and Web of Science (RRID:SCR_022706). A total of 1,332 studies were retrieved, of which 940 remained after removing duplicates. Ultimately, a total of 8 studies were included in the review. The included studies were randomized controlled trials, quasi-experimental studies and pilot studies implementing an IF intervention (time-restricted eating, alternate day fasting or 5:2 diet) in healthy subjects or subjects with any disease.

Results

Most studies found an association between IF and gut microbiota richness, diversity and compositional changes. There was heterogeneity in the results, and bacteria which were found to be statistically significantly affected by IF varied widely depending on the study.

Conclusion

The findings in this systematic review suggest that IF influences gut microbiota. It seems possible that IF can improve richness and alpha diversity. Due to the substantial heterogeneity of the results, more research is required to validate these findings and clarify whether the compositional changes might be beneficial to human health.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021241619.

Design of a Remote Time-Restricted Eating and Mindfulness Intervention to Reduce Risk Factors Associated with Early-Onset Colorectal Cancer Development among Young Adults

Early-onset colorectal cancer (EOCRC) is defined as a diagnosis of colorectal cancer (CRC) in individuals younger than 50 years of age. While overall CRC rates in the United States (US) decreased between 2001 and 2018, EOCRC rates have increased. This research project aims to evaluate the feasibility and acceptability of Time-Restricted Eating (TRE), Mindfulness, or TRE combined with Mindfulness among young to middle-aged adults at risk of EOCRC. Forty-eight participants will be randomly assigned to one of four groups: TRE, Mindfulness, TRE and Mindfulness, or Control. Data on feasibility, adherence, and acceptability will be collected. Measures assessed at baseline and post-intervention will include body weight, body composition, dietary intake, physical activity, sleep behavior, circulating biomarkers, hair cortisol, and the gut microbiome. The effects of the intervention on the following will be examined: (1) acceptability and feasibility; (2) body weight, body composition, and adherence to TRE; (3) circulating metabolic, inflammation, and oxidative stress biomarkers; (4) intestinal inflammation; and (5) the gut microbiome. TRE, combined with Mindfulness, holds promise for stress reduction and weight management among individuals at risk of EOCRC. The results of this pilot study will inform the design and development of larger trials aimed at preventing risk factors associated with EOCRC.

Time-restricted eating: Watching the clock to treat obesity

Time-restricted eating (TRE) has become a popular strategy to treat obesity. TRE involves confining the eating window to 4-10 h per day and fasting for the remaining hours (14-20 h fast). During the eating window, individuals are not required to monitor food intake. The sudden rise in popularity of TRE is most likely due to its simplicity and the fact that it does not require individuals to count calories to lose weight. This feature of TRE may appeal to certain individuals with obesity, and this could help produce lasting metabolic health improvements. The purpose of this review is to summarize current evidence from randomized clinical trials of TRE (without calorie counting) on body weight and metabolic risk factors. The efficacy of TRE in various populations groups, including those with obesity, type 2 diabetes (T2DM), and polycystic ovary syndrome (PCOS), is also examined.

Ketone flux through BDH1 supports metabolic remodeling of skeletal and cardiac muscles in response to intermittent time-restricted feeding

Time-restricted feeding (TRF) has gained attention as a dietary regimen that promotes metabolic health. This study questioned if the health benefits of an intermittent TRF (iTRF) schedule require ketone flux specifically in skeletal and cardiac muscles. Notably, we found that the ketolytic enzyme beta-hydroxybutyrate dehydrogenase 1 (BDH1) is uniquely enriched in isolated mitochondria derived from heart and red/oxidative skeletal muscles, which also have high capacity for fatty acid oxidation (FAO). Using mice with BDH1 deficiency in striated muscles, we discover that this enzyme optimizes FAO efficiency and exercise tolerance during acute fasting. Additionally, iTRF leads to robust molecular remodeling of muscle tissues, and muscle BDH1 flux does indeed play an essential role in conferring the full adaptive benefits of this regimen, including increased lean mass, mitochondrial hormesis, and metabolic rerouting of pyruvate. In sum, ketone flux enhances mitochondrial bioenergetics and supports iTRF-induced remodeling of skeletal muscle and heart.

Time of eating and mortality in U.S. adults with heart failure: Analyses of the National Health and Nutrition Examination Survey 2003-2018

BACKGROUND AND AIMS

Promising associations have been demonstrated between delayed last eating occasion and cardiorespiratory fitness in adults with heart failure (HF), however, it is unknown if time of eating is associated with clinical endpoints such as mortality. This study aimed to examine associations between time of eating variables and all-cause and cardiovascular mortality in the National Health and Nutrition Examination Survey (NHANES).

METHODS AND RESULTS

Participants self-disclosed HF diagnosis. Two dietary recalls were obtained and categorical variables were created based on mean time of first eating occasion (8:31 AM), last eating occasion (7:33 PM) and eating window (11.02 h). Mortality was obtained through linkage to the National Death Index. Covariate-adjusted Cox proportional hazard regression models were created examining the association between time of eating and mortality. Participants (n = 991) were 68 (95 % CI 67-69) years of age, 52.6 (95 % CI 49.0-56.3)% men and had a body mass index of 32.5 (95 % CI 31.8-33.2) kg/m2 with follow up time of 68.9 (95 % CI 64.8-72.9) person-months. When models were adjusted for time of eating variables and all other covariates, extending the eating window beyond 11.02 h was associated with decreased risk of cardiovascular (HR 0.36 [95 % CI 0.16-0.81]), but not all-cause mortality. Time of first and last eating occasions were not associated with mortality.

CONCLUSIONS

In adults with HF, an extended eating window is associated with reduced risk for cardiovascular mortality. Randomized controlled trials should examine if extending the eating window can improve prognostic indicators such as cardiorespiratory fitness in this population.

The Impact of Time-Restricted Meal Intake on Glycemic Control and Weight Management in Type 2 Diabetes Mellitus Patients: An 18-Month Longitudinal Study

AIMS

This study aimed to investigate the impact of time-restricted meal intake (TRM) on anthropometric and biochemical parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 400 patients diagnosed with T2DM were selected from the Endocrinology Department at King George's Medical University (KGMU), Lucknow, based on the American Diabetes Association (ADA) guidelines and specific criteria. A total of 127 patients were lost to follow-up, resulting in 273 patients who completed the study. The patients were randomly assigned to two groups: the TRM group (consenting to have an early dinner at 7 pm) and the control group (non-TRM/late-night eater group). Baseline data were recorded, and follow-up assessments were conducted at six months, 12 months, and 18 months. Informed consent was obtained, and a diet chart was regularly maintained and updated.

RESULTS

 The TRM group experienced a significant weight loss of 3.88 kg (5.45%) and a substantial reduction in BMI by 1.5 units (5.26%). In contrast, the non-TRM/control group had smaller reductions in weight (1.36 kg, 1.77%) and BMI (0.5 units, 1.65%). TRM group showed significant reductions in fasting blood sugar levels by 33.9 mg/dl (21.17%), postprandial blood sugar levels by 94.6 mg/dl (38.88%), and glycosylated hemoglobin (HbA1c) levels by 1.37 (15.87%). These improvements were significantly greater than the reductions observed in the control group, which had decreases of 29.3 mg/dl (17.85%) in fasting blood sugar levels, 41.6 mg/dl (16.84%) in postprandial blood sugar levels, and 0.59 (6.89%) in HbA1c levels.

CONCLUSION

Our findings underscore the potential of TRM as an effective strategy for weight management and glycemic control in patients with T2DM, even in a long-term context. These results support time-restricted eating as a sustainable lifestyle modification for managing chronic metabolic diseases.

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.

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.

A Systematic Review and Meta-Analysis of the Impacts of Time-Restricted Eating on Metabolic Homeostasis

This meta-analysis investigated the effect of time-restricted eating (TRE) as an economical lifestyle intervention for the prevention of metabolic syndrome and improving the related metabolic variables. The Cochrane library, MEDLINE, EMBASE, clinical trials, and other databases were searched for randomized controlled trials (RCTs). We included 22 RCTs (1004 participants, aged 18-75 years, including healthy subjects, prediabetes and overweight patients) designed to evaluate the effect of TRE on metabolic parameters. Body mass index (BMI) (-0.56 kg/m2, 95% CI: -1.00, -0.13, P < .01), fasting blood glucose (-1.74 mmol/L, 95% CI: -3.34, -0.14, P < .01), and body weight (-0.48 kg, 95% CI: -0.74, -0.22, P < .01) in the TRE intervention group were decreased to varying degrees compared with controls. In contrast, high-density lipoprotein cholesterol (HDL-C) levels were significantly increased in the TRE group compared with the control group (P < .01). The change in waist circumference, blood pressure, triglycerides, low-density lipoprotein cholesterol (LDL-C), and total cholesterol did not vary markedly across the groups. In conclusion, this meta-analysis found a significant reduction in BMI, weight, and fasting glucose, as well as a rise in HDL-C level with TRE compared with control. TRE could be used as an adjuvant treatment for metabolic dysfunctions.

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.

Diabesity and Dietary Interventions: Evaluating the Impact of Mediterranean Diet and Other Types of Diets on Obesity and Type 2 Diabetes Management

BACKGROUND

Diabesity, the intersection of obesity and diabetes, presents a global health crisis with profound implications. Addressing diabesity requires multifaceted strategies, with diet playing a pivotal role. Over the last 15 years, clinical studies have intensified their exploration of various dietary approaches in diabesity management. This literature review aims to synthesize findings from clinical studies conducted in the last 15 years, shedding light on the efficacy, mechanisms, and nuances of different diet types in diabesity management with special focus on the Mediterranean diet (MD).

METHODS

Thorough research of academic databases yielded a collection of relevant clinical studies. These studies encompassed a range of dietary strategies, including the MD, low-carbohydrate diets, plant-based diets, high-protein diets, low-fat regimens, and intermittent fasting. Key findings, methodologies, and outcomes were thoroughly extracted and analyzed.

RESULTS

The last 15 years have witnessed considerable improvements in recognizing the role of human nutritional habits in diabesity management. The MD appears to be the most well-recognized diet, exerting favorable effects against both obesity and diabetes. Low-carbohydrate diets were found to enhance glycemic regulation and decrease insulin resistance. Plant-based diets demonstrated potential benefits in weight management and cardiometabolic health. High-protein, low-fat dietary models exhibited positive effects on satiety and body weight decline. Intermittent fasting regimens also exerted metabolic improvements and body weight decline. Personalization emerged as a crucial factor in dietary recommendations.

CONCLUSIONS

Clinical studies from the last 15 years underscore the intricate relationship between diet types and diabesity management. The above results contribute to an increasing body of evidence, emphasizing the need for tailored dietary approaches and especially the MD. Healthcare providers can utilize this knowledge to offer personalized dietary recommendations for individuals with diabesity, potentially curbing the rise of these twin epidemics and improving the well-being of affected populations.

Stress and human health in diabetes: A report from the 19th Chicago Biomedical Consortium symposium

Stress and diabetes coexist in a vicious cycle. Different types of stress lead to diabetes, while diabetes itself is a major life stressor. This was the focus of the Chicago Biomedical Consortium's 19th annual symposium, "Stress and Human Health: Diabetes," in November 2022. There, researchers primarily from the Chicago area met to explore how different sources of stress - from the cells to the community - impact diabetes outcomes. Presenters discussed the consequences of stress arising from mutant proteins, obesity, sleep disturbances, environmental pollutants, COVID-19, and racial and socioeconomic disparities. This symposium showcased the latest diabetes research and highlighted promising new treatment approaches for mitigating stress in diabetes.

Intermittent fasting and bone health: a bone of contention?

Intermittent fasting (IF) is a promising strategy for weight loss and improving metabolic health, but its effects on bone health are less clear. This review aims to summarise and critically evaluate the preclinical and clinical evidence on IF regimens (the 5:2 diet, alternate-day fasting (ADF) and time-restricted eating (TRE)/time-restricted feeding and bone health outcomes. Animal studies have utilised IF alongside other dietary practices known to elicit detrimental effects on bone health and/or in models mimicking specific conditions; thus, findings from these studies are difficult to apply to humans. While limited in scope, observational studies suggest a link between some IF practices (e.g. breakfast omission) and compromised bone health, although lack of control for confounding factors makes these data difficult to interpret. Interventional studies suggest that TRE regimens practised up to 6 months do not adversely affect bone outcomes and may even slightly protect against bone loss during modest weight loss (< 5 % of baseline body weight). Most studies on ADF have shown no adverse effects on bone outcomes, while no studies on the ‘5–2’ diet have reported bone outcomes. Available interventional studies are limited by their short duration, small and diverse population samples, assessment of total body bone mass exclusively (by dual-energy X-ray absorptiometry) and inadequate control of factors that may affect bone outcomes, making the interpretation of existing data challenging. Further research is required to better characterise bone responses to various IF approaches using well-controlled protocols of sufficient duration, adequately powered to assess changes in bone outcomes and designed to include clinically relevant bone assessments.

Time-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet

Nonalcoholic fatty liver disease (NAFLD), a condition characterized by the accumulation of fat in the liver, is estimated to be the most common liver disease worldwide. Obesity is a major risk factor and contributor, and, accordingly, weight loss can improve NAFLD. Previous studies in preclinical models of diet-induced obesity and fatty liver disease have shown the independent benefits of resistance exercise training (RT) and time-restricted feeding (TRF) in preventing weight gain and hepatic build-up of fat. Here, we tested the combined effect of TRF and RT on obesity and NAFLD in mice fed a high-fat diet. Our results showed that both TRF-8-h food access in the active phase-and RT-consisting of three weekly sessions of ladder climbing-attenuated body weight gain, improved glycemic homeostasis, and decreased the accumulation of lipids in the liver. TRF combined with RT improved the respiratory exchange rate, energy expenditure, and mitochondrial respiration in the liver. Furthermore, gene expression analysis in the liver revealed lower mRNA expression of lipogenesis and inflammation genes along with increased mRNA of fatty acid oxidation genes in the TRF + RT group. Importantly, combined TRF + RT was shown to be more efficient in preventing obesity and metabolic disorders. In conclusion, TRF and RT exert complementary actions compared with isolated interventions, with significant effects on metabolic disorders and NAFLD in mice.NEW & NOTEWORTHY Whether time-restricted feeding (TRF) combined with resistance exercise training (RT) may be more efficient compared with these interventions alone is still unclear. We show that when combined with RT, TRF provided additional benefits, being more effective in increasing energy expenditure, preventing weight gain, and regulating glycemic homeostasis than each intervention alone. Thus, our results demonstrate that TRF and RT have complementary actions on some synergistic pathways that prevented obesity and hepatic liver accumulation.

Impact of 8-hour time-limited eating on sleep in adolescents with obesity

STUDY OBJECTIVES

The relationship between time-limited eating (TLE) and sleep quality is a topic of growing interest in the field of chronobiology. Data in adult cohorts shows that TLE may improve sleep quality, but this has not been evaluated in adolescents. The aim of this secondary analysis was to (1) examine the impact of 8-hour TLE on sleep parameters in youth with obesity and (2) explore if there was any association between sleep patterns and glycemic profiles.

METHODS

Adolescents with obesity were randomized into one of three groups: 8-hour TLE (participants self-selected their eating window) + real-time continuous glucose monitor, 8-hour TLE + blinded continuous glucose monitor, or a prolonged eating window. In the primary analysis, it was found that participants in the real-time continuous glucose monitor group + 8-hour TLE group did not access their continuous glucose monitor data and thus for this analysis the two TLE groups were combined and only completers who had available Pittsburgh Sleep Quality Index (PSQI) data at all three time points were included. Participants completed the PSQI at baseline, week 4, and week 12. Mixed-effects generalized linear regression models were utilized to examine the change in PSQI score and assess association between glycemic variability and PSQI total score overtime by intervention arm.

RESULTS

The median PSQI total score for the TLE groups (n = 27) was 6 at week 0 (interquartile range = 5 to 10) and 5 at week 12 (interquartile range = 2 to 7). There was no significant difference in the change in total PSQI score or sleep latency between TLE and control over the study period (P > .05). There was no association between PSQI score and change in weight or glycemic profile between groups (all P values > 0.05).

CONCLUSIONS

These results suggest that in adolescents with obesity, an 8-hour TLE approach did not negatively impact sleep quality or efficiency when compared to a prolonged eating window. The potential effects of TLE on sleep should be further investigated in larger randomized trials.

CITATION

Jayakumr A, Gillett ES, Wee CP, Kim A, Vidmar AP. Impact of 8-hour time-limited eating on sleep in adolescents with obesity. J Clin Sleep Med. 2023;19(11):1941-1949.

Intermittent fasting associated with aerobic exercise improves oxidative parameters and causes muscle damage without compromising the performance of Wistar rats

OBJECTIVES

The aim of this study was to` investigate the effects of intermittent fasting (IF) and the possible association with aerobic exercise on performance, oxidative, biochemical, and somatic parameters of Wistar rats.

METHODS

Forty rats were randomized into the following groups: sedentary (SC) and trained (TC) controls, sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF). The rats were subjected to IF for 15 h every day and aerobic exercise lasting 30 min, five times a week, at a speed of 15 m/min for 4 wk. Performance tests were performed at the beginning and end of the protocol. Glucose and insulin tolerance, somatic parameters, lipidogram, leptin, insulin, malondialdehyde, antioxidant capacity, C-reactive protein, alpha acid glycoprotein, creatine kinase, lactate dehydrogenase, and muscle histology were analyzed.

RESULTS

The trained groups had similar performance and significantly improved performance at the end of the experiment. TIF showed lower body weight (-16 g), lean mass (22.49%), homeostatic model assessment for insulin resistance (29%), and lactate dehydrogenase (48%), and higher malondialdehyde (53%) and antioxidant capacity (75%) than the TC group. The SIF and TIF groups showed a fiber area reduction and positivity marking for tumor necrosis factor-α in the muscles.

CONCLUSION

Although IF associated with aerobic exercise improved antioxidant capacity caused damage to muscle fibers and lean mass loss, it did not change the performance of the rats.

Time-restricted eating with calorie restriction on weight loss and cardiometabolic risk: a systematic review and meta-analysis

The effect of time-restricted eating (TRE) has been summarized in previous studies, but its benefits in combination with calorie restriction (CR) still need to be determined. The present meta-analysis aimed to evaluate the efficacy of TRE with CR on weight loss and cardiometabolic risk. PubMed, Embase, Cochrane Library, and gray literature databases were searched from inception to October 18, 2022, for potential randomized controlled trial (RCT) studies based on predefined inclusion and exclusion criteria. Body weight and other cardiometabolic risk factors were described as weighted mean difference (WMD) with a 95% confidence interval (CI). Eight RCTs involving 579 participants were enrolled in the present analysis. The pooled results showed that TRE with CR reduced the body weight, fat mass, and waist circumference significantly (WMD: -1.40, 95% CI: -1.81 to -1.00, and I2: 0%; WMD: -0.73, 95% CI: -1.39 to -0.07, and I2: 0%; WMD: -1.87, 95% CI: -3.47 to -0.26, and I2: 67.25%, respectively). However, compared with CR alone, TRE plus CR exhibited no significant benefit on the blood pressure, glucose profile, and lipid profile. Subgroup analysis suggested that early TRE is more effective in weight loss (WMD: -1.42, 95% CI: -1.84 to -1.01, and I2: 0%) and improving fat mass (WMD: -1.06, 95% CI: -1.91 to -0.22, and I2: 0%) than delayed or broader TRE when combined with CR. Although the combination of TRE and CR can effectively decrease body weight, fat mass, and waist circumference, the long-term effects, particularly those on cardiometabolic risk in participants with chronic cardiovascular disease and diabetes, remain to be explored.

Glycaemic variability, assessed with continuous glucose monitors, is associated with diet, lifestyle and health in people without diabetes

Background

Continuous glucose monitors (CGMs) provide high-frequency information regarding daily glucose variation and are recognised as effective for improving glycaemic control in individuals living with diabetes. Despite increased use in individuals with non-diabetic blood glucose concentrations (euglycemia), their utility as a health tool in this population remains unclear.

Objectives

To characterise variation in time in range (TIR) and glycaemic variability in large populations without diabetes or impaired glucose tolerance; describe associations between CGM-derived glycaemic metrics and metabolic and cardiometabolic health traits; identify key diet and lifestyle factors associated with TIR and glycaemic variability.

Design

Glycaemic variability (coefficient of variation) and time spent in both the ADA secondary target range (TIRADA; 3.9-7.8 mmol/L) and a more stringent range (TIR3.9-5.6; 3.9-5.6 mmol/L) were calculated during free-living in PREDICT 1, PREDICT 2, and PREDICT 3 euglycaemic community-based volunteer cohorts. Associations between CGM derived glycaemic metrics, markers of cardiometabolic health, diet (food frequency questionnaire and logged diet records), diet-habits, and lifestyle were explored.

Results

Data from N=4135 participants (Mean SD; Age: 47 12 y; Sex: 83% Female, BMI: 27 6 kg/m2). Median glycaemic variability was 14.8% (IQR 12.6-17.6%), median TIRADA was 95.8% (IQR 89.6-98.6%) and TIR3.9-5.6 was 75.0% (IQR 64.6-82.8%). Greater TIR3.9-5.6 was associated with lower HbA1c, ASCVD 10y risk and HOMA-IR (all p < 0.05). Lower glycaemic variability was associated with lower % energy derived from carbohydrate (rs: 0.17, p < 0.01), ultra-processed foods (NOVA 4, % EI; rs: 0.12, p = 0.01) and a longer overnight fasting duration (rs: -0.10, p = 0.01).

Conclusions

A stringent TIR target provides sensitivity to detect changes in HOMA-IR, ASCVD 10 y risk and HbA1c that were not detected using ADA secondary targets. Associations among TIR, glycaemic variability, dietary intake (e.g. carbohydrate and protein) and habits (e.g. nocturnal fasting duration) highlight potential strategic targets to improve glycaemic metrics derived from continuous glucose monitors.

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.

Effect of Time-Restricted Eating versus Daily Calorie Restriction on Mood and Quality of Life in Adults with Obesity

The purpose of this secondary analysis is to compare the effects of two popular weight loss regimens, time-restricted eating (TRE) and daily calorie restriction (CR), on mood and quality-of-life measures in adults with obesity. Ninety participants were randomized to one of three interventions for 12 months: 8 h TRE (eating only between 12:00 and 8:00 p.m., with no calorie counting); CR (25% energy restriction daily); or no-intervention control group. Questionnaires were administered to measure mood (Beck Depression Inventory-II (BDI-II), and Profile of Mood States (POMS)) and quality of life (Rand 36-Item Short Form) at baseline and month 12. Body weight decreased in the TRE group (-4.87%, 95%CI: -7.61, -2.13) and CR group (-5.30%, 95%CI: -9.06, -1.54) versus controls, with no difference between TRE and CR. The BDI-II depression score did not change in the TRE or CR group, versus controls, by month 12. Likewise, there were no changes in any of the POMS subscales (tension, depression, anger, fatigue, anger, confusion, or vigor) or the total mood disturbance score in the TRE or CR group versus controls. As for quality of life, there were no significant changes in the SF-36 constructs of mental health, bodily pain, and general physical health in the TRE or CR group versus controls. However, there was a trend towards increased vitality in the TRE group (7.77 [95% CI: 0.15, 15.39] p = 0.05) relative to controls. There were no associations between changes in body weight, physical activity, mood, and quality of life in any group by the end of the study. These findings suggest that TRE and CR produce similar degrees of weight loss, but impact neither mood nor quality of life in adults with obesity over 12 months. Future well-powered studies will be needed to confirm these findings.

Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial

Importance

Time-restricted eating (TRE) has become increasingly popular, yet longer-term randomized clinical trials have not evaluated its efficacy and safety in patients with type 2 diabetes (T2D).

Objective

To determine whether TRE is more effective for weight reduction and glycemic control than daily calorie restriction (CR) or a control condition in adults with T2D.

Design, Setting, and Participants

This 6-month, parallel-group, randomized clinical trial was performed between January 25, 2022, and April 1, 2023, at the University of Illinois Chicago. Participants were aged 18 to 80 years with obesity and T2D. Data analysis was based on intention to treat.

Interventions

Participants were randomized to 1 of 3 groups: 8-hour TRE (eating 12 to 8 pm only, without calorie counting), CR (25% energy restriction daily), or control.

Main Outcomes and Measures

The primary outcome measure was change in body weight by month 6. Secondary outcomes included changes in hemoglobin A1c (HbA1c) levels and metabolic risk factors.

Results

Seventy-five participants were enrolled with a mean (SD) age of 55 (12) years. The mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 39 (7) and the mean (SD) HbA1c level was 8.1% (1.6%). A total of 53 participants (71%) were women. One participant (1%) was Asian, 30 (40%) were Hispanic White, 40 (53%) were non-Hispanic Black, and 4 (5%) were non-Hispanic White. Participants in the TRE group were adherent with their eating window on a mean (SD) of 6.1 (0.8) days per week, and 17 (68%) in the CR group were adherent with their prescribed calorie goals over 6 months. The mean (SD) reduction in energy intake was -313 (509) kcal/d for TRE, -197 (426) kcal/d for CR, and -16 (439) kcal/d for controls. By month 6, body weight decreased significantly in the TRE group (-3.56% [95% CI, -5.92% to -1.20%]; P = .004) but not the CR group (-1.78% [95% CI, -3.67% to 0.11%]; P = .06), relative to controls. Levels of HbA1c decreased in the TRE (-0.91% [95% CI, -1.61% to -0.20%]) and CR (-0.94% [95% CI, -1.59% to -0.30%]) groups, relative to controls, with no differences between the TRE and CR groups. Time in euglycemic range, medication effect score, blood pressure, and plasma lipid levels did not differ among groups. No serious adverse events were reported.

Conclusions and relevance

This randomized clinical trial found that a TRE diet strategy without calorie counting was effective for weight loss and lowering of HbA1c levels compared with daily calorie counting in a sample of adults with T2D. These findings will need to be confirmed by larger RCTs with longer follow-up.

Trial Registration

ClinicalTrials.gov Identifier: NCT05225337.

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.

Efficacy of Time-Restricted Eating and Behavioral Economic Intervention in Reducing Fasting Plasma Glucose, HbA1c, and Cardiometabolic Risk Factors in Patients with Impaired Fasting Glucose: A Randomized Controlled Trial

This randomized controlled trial is aimed at assessing the efficacy of combining time-restricted eating (TRE) with behavioral economic (BE) interventions and comparing it to TRE alone and to the usual care for reducing fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and other cardiometabolic risk factors among patients with impaired fasting glucose (IFG). Seventy-two IFG patients aged 18-65 years were randomly allocated for TRE with BE interventions (26 patients), TRE alone (24 patients), or usual care (22 patients). Mean FPG, HbA1c, and other cardiometabolic risk factors among the three groups were compared using a mixed-effect linear regression analysis. Mean body weight, FPG, HbA1c, fasting insulin, and lipid profiles did not significantly differ among the three groups. When considering only patients who were able to comply with the TRE protocol, the TRE group showed significantly lower mean FPG, HbA1c, and fasting insulin levels compared to the usual care group. Our results did not show significant differences in body weight, blood sugar, fasting insulin, or lipid profiles between TRE plus BE interventions, TRE alone, and usual care groups. However, TRE might be an effective intervention in lowering blood sugar levels for IFG patients who were able to adhere to the TRE protocol.

Gestational Early-Time Restricted Feeding Results in Sex-Specific Glucose Intolerance in Adult Male Mice

The timing of food intake is a novel dietary component that impacts health. Time-restricted feeding (TRF), a form of intermittent fasting, manipulates food timing. The timing of eating may be an important factor to consider during critical periods, such as pregnancy. Nutrition during pregnancy, too, can have a lasting impact on offspring health. The timing of food intake has not been thoroughly investigated in models of pregnancy, despite evidence that interest in the practice exists. Therefore, using a mouse model, we tested body composition and glycemic health of gestational early TRF (eTRF) in male and female offspring from weaning to adulthood on a chow diet and after a high-fat, high-sucrose (HFHS) diet challenge. Body composition was similar between groups in both sexes from weaning to adulthood, with minor increases in food intake in eTRF females and slightly improved glucose tolerance in males while on a chow diet. However, after 10 weeks of HFHS, male eTRF offspring developed glucose intolerance. Further studies should assess the susceptibility of males, and apparent resilience of females, to gestational eTRF and assess mechanisms underlying these changes in adult males.

Rationale and design of IMPACT-women: a randomised controlled trial of the effect of time-restricted eating, healthy eating and reduced sedentary behaviour on metabolic health during chemotherapy for early-stage breast cancer

Metabolic dysfunction and excess accumulation of adipose tissue are detrimental side effects from breast cancer treatment. Diet and physical activity are important treatments for metabolic abnormalities, yet patient compliance can be challenging during chemotherapy treatment. Time-restricted eating (TRE) is a feasible dietary pattern where eating is restricted to 8 h/d with water-only fasting for the remaining 16 h. The purpose of this study is to evaluate the effect of a multimodal intervention consisting of TRE, healthy eating, and reduced sedentary time during chemotherapy treatment for early-stage (I-III) breast cancer on accumulation of visceral fat (primary outcome), other fat deposition locations, metabolic syndrome and cardiovascular disease risk (secondary outcomes) compared with usual care. The study will be a two-site, two-arm, parallel-group superiority randomised control trial enrolling 130 women scheduled for chemotherapy for early-stage breast cancer. The intervention will be delivered by telephone, including 30-60-minute calls with a registered dietitian who will provide instructions on TRE, education and counselling on healthy eating, and goal setting for reducing sedentary time. The comparison group will receive usual cancer and supportive care including a single group-based nutrition class and healthy eating and physical activity guidelines. MRI, blood draws and assessment of blood pressure will be performed at baseline, after chemotherapy (primary end point), and 2-year follow-up. If our intervention is successful in attenuating the effect of chemotherapy on visceral fat accumulation and cardiometabolic dysfunction, it has the potential to reduce risk of cardiometabolic disease and related mortality among breast cancer survivors.

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.

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.