Effects of 4- and 6-h Time-Restricted Feeding on Weight and Cardiometabolic Health: A Randomized Controlled Trial in Adults with Obesity

Time-restricted feeding attenuates gluconeogenic activity through inhibition of PGC-1α expression and activity

BACKGROUND

Time-restricted feeding (TRF), a key component of intermittent fasting regimens, has gained considerable attention in recent years due to reversing obesity and insulin resistance. To the best of our knowledge, here, we reported for the first time the underlying mechanistic therapeutic efficacy of TRF against hepatic gluconeogenic activity in obese mice.

METHODS

The obese mice were subjected to either ad lib or TRF of a high fat diet for 8 h per day for 4 weeks. Western blotting, qRT-PCR, and plasma biochemical analyses were applied.

RESULTS

The present findings showed that TRF regimen reduced food intake, and reversed high fat diet-induced glucose intolerance, hyperglycemia and insulin resistance in mice of high fat diet-induced obesity. Mechanistically, we confirmed that TRF regimen protected against hyperglycemia and ameliorated hepatic gluconeogenic activity through inhibition of p38 MAPK/SIRT1/PGC-1α signal pathway.

CONCLUSION

Our findings suggest that TRF regimen might be a potential novel nonpharmacological strategy against obesity/diabetes-induced hyperglycemia and insulin resistance.

Ten things to know about ten cardiovascular disease risk factors

Given rapid advancements in medical science, it is often challenging for the busy clinician to remain up-to-date on the fundamental and multifaceted aspects of preventive cardiology and maintain awareness of the latest guidelines applicable to cardiovascular disease (CVD) risk factors. The "American Society for Preventive Cardiology (ASPC) Top Ten CVD Risk Factors 2021 Update" is a summary document (updated yearly) regarding CVD risk factors. This "ASPC Top Ten CVD Risk Factors 2021 Update" summary document reflects the perspective of the section authors regarding ten things to know about ten sentinel CVD risk factors. It also includes quick access to sentinel references (applicable guidelines and select reviews) for each CVD risk factor section. The ten CVD risk factors include unhealthful nutrition, physical inactivity, dyslipidemia, hyperglycemia, high blood pressure, obesity, considerations of select populations (older age, race/ethnicity, and sex differences), thrombosis/smoking, kidney dysfunction and genetics/familial hypercholesterolemia. For the individual patient, other CVD risk factors may be relevant, beyond the CVD risk factors discussed here. However, it is the intent of the "ASPC Top Ten CVD Risk Factors 2021 Update" to provide a succinct overview of things to know about ten common CVD risk factors applicable to preventive cardiology.

Daily Timing of Meals and Weight Loss After Bariatric Surgery: a Systematic Review

The timing of food intake throughout the day can alter circadian clocks and metabolism to modulate the course of obesity. We conducted a systematic literature review to determine whether the timing of meals could alter the change in body weight after bariatric surgery in adults. Twelve cohort studies examined the association between meal timing and changes in body weight after bariatric surgery. Eight studies suggested an association between meal timing and weight loss. All studies examined simple exposure variables such as frequency of breakfast or dinner consumption and overnight meals. Overall, the low-quality evidence that food consumption at the end of the day is associated with lower weight loss after bariatric surgery in adults warrants further research.

Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians

Background

Type 2 Diabetes is a metabolic disorder characterized by hyperglycemia that causes numerous complications with significant long-term morbidity and mortality. The disorder is primarily due to insulin resistance particularly in liver, skeletal muscle, and adipose tissue. In this review, we detail the hormonal mechanisms leading to the development of diabetes and discuss whether intermittent fasting should be considered as an alternative, non-medicinal treatment option for patients with this disorder.

Methods

We searched PubMed, Ovid MEDLINE, and Google Scholar databases for review articles, clinical trials, and case series related to type 2 diabetes, insulin resistance, and intermittent fasting. Articles were carefully reviewed and included based on relevance to our topic. We excluded abstracts and any non-English articles.

Results

The majority of the available research demonstrates that intermittent fasting is effective at reducing body weight, decreasing fasting glucose, decreasing fasting insulin, reducing insulin resistance, decreasing levels of leptin, and increasing levels of adiponectin. Some studies found that patients were able to reverse their need for insulin therapy during therapeutic intermittent fasting protocols with supervision by their physician.

Conclusion

Current evidence suggests that intermittent fasting is an effective non-medicinal treatment option for type 2 diabetes. More research is needed to delineate the effects of intermittent fasting from weight loss. Physicians should consider educating themselves regarding the benefits of intermittent fasting. Diabetic patients should consult their physician prior to beginning an intermittent fasting regimen in order to allow for appropriate oversight and titration of the patients medication regimen during periods of fasting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40842-020-00116-1.

The role of the molecular circadian clock in human energy homeostasis

PURPOSE OF REVIEW

The aim of this review is to present the latest findings on the role of the circadian clock in the control of metabolism, and the therapeutic potential of chronotherapy to regulate energy homeostasis in humans.

RECENT FINDINGS

We summarized the recent advances related to circadian clock regulation of food intake and energy expenditure. In peripheral organs, mitochondrial oxidative capacity and lipolysis show circadian pattern in humans, and rhythms disruption may be involved in the pathogenesis of metabolic diseases. Indeed, circadian desynchrony affects food intake, insulin sensitivity, and increases the risk of developing metabolic disease. Time-targeted strategies, which aim to synchronize external cues with the molecular clock to improve metabolic outcomes, have positive effects on metabolism in humans, with several studies showing that time-targeted feeding improves body weight loss and glucose tolerance.

SUMMARY

The interest in time-targeted strategies to prevent or manage metabolic disturbances has grown this past year with encouraging health benefits. To maximize the therapeutic effect of these strategies, further research is warranted to delineate the molecular regulation of metabolic processes controlled by the clock and especially its modulation in contexts such as aging, sex differences, or metabolic diseases.

Watching, keeping and squeezing time to lose weight: Implications of time-restricted eating in daily life

Time-restricted eating (TRE) is a novel intervention that allows eating and drinking within a certain time window and has shown positive effects on body weight in few studies. Weight loss strategies that easily can be integrated into daily life are needed, but knowledge about how TRE affects daily life is lacking. This study examined how individuals having overweight or obesity at high risk of type 2 diabetes performed TRE in daily life, with a focus on how the timing of eating changed the organisation and rhythms of daily activities. Semi-structured interviews were conducted with participants enrolled in a randomised controlled trial studying the effect of a 12-week TRE intervention focusing on a self-selected daily 10-h window between 6 AM and 8 PM. Seventeen participants from the intervention group were interviewed at baseline and end of intervention, and data were analysed using a thematic analysis approach. Participants found TRE simple and appealing due to the unrestricted dietary intake. In general, participants did not change their food preferences and continued to eat three main daily meals. However, participants had to increase their awareness of the time of day, reshuffle ordinary daily activities and plan their intake more carefully. Two participants reported fully adherence every day, whereas all other participants reported one to several episodes of intake outside their window during the 12 weeks. Social evening activities and collective rhythms were largest barriers. Our findings suggest that TRE interventions would benefit from a broader perspective on daily life and an expanded view on families and friends as joint units of intervention. TRE interventions should consider individuals' daily rhythms and help them develop practical solutions to integrating new eating practices.

Pilot Clinical Trial of Time-Restricted Eating in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) and erratic eating patterns are associated with circadian rhythm disruption which contributes to an increased cardiometabolic risks. Restricting eating period (time-restricted eating, TRE) can restore robust circadian rhythms and improve cardiometabolic health. We describe a protocol of the Time-Restricted Eating on Metabolic and Neuroendocrine homeostasis, Inflammation, and Oxidative Stress (TREMNIOS) pilot clinical trial in Polish adult patients with MetS and eating period of ≥14 h/day. The study aims to test the feasibility of TRE intervention and methodology for evaluating its efficacy for improving metabolic, neuroendocrine, inflammatory, oxidative stress and cardiac biomarkers, and daily rhythms of behavior for such population. Participants will apply 10-h TRE over a 12-week monitored intervention followed by a 12-week self-directed intervention. Changes in eating window, body weight and composition, biomarkers, and rhythms of behavior will be evaluated. Dietary intake, sleep, activity and wellbeing will be monitored with the myCircadianClock application and questionnaires. Adherence to TRE defined as the proportion of days recorded with app during the monitored intervention in which participants satisfied 10-h TRE is the primary outcome. TREMNIOS will also provide an exploratory framework to depict post-TRE changes in cardiometabolic outcomes and behavior rhythms. This protocol extends previous TRE-related protocols by targeting European population with diagnosed MetS and including long-term intervention, validated tools for monitoring dietary intake and adherence, and comprehensive range of biomarkers. TREMNIOS trial will lay the groundwork for a large-scale randomized controlled trial to determine TRE efficacy for improving cardiometabolic health in MetS population.

Effect of time restricted eating on body weight and fasting glucose in participants with obesity: results of a randomized, controlled, virtual clinical trial

Background

Time restricted eating (TRE) is an emerging dietary intervention for weight loss that is hypothesized to reinforce the metabolic benefits of nightly fasting/ketosis. This pilot study investigated the effectiveness of a daily 14-h metabolic fast (14:10 TRE beginning after dinner, a “fasting snack” at hour 12, and ending with breakfast 14 h later) combined with a commercial weight management program on body weight and fasting blood glucose (FBG) in individuals with obesity. We also investigated the effect of the low-calorie, high-fat, low-carbohydrate, and low-protein “fasting snack” on blood glucose.

Methods

This 8-week, randomized, controlled, clinical trial included men and women (BMI ≥ 30 kg/m²) between June and October 2020. Study procedures were conducted remotely. Participants were randomized to 14:10 or 12-h TRE (12:12, active comparator) and prescribed a diet (controlled for calories and macronutrient composition) and exercise program that included weekly customized counseling and support. The primary outcome was change from baseline in body weight in the 14:10 group.

Results

Of the 78 randomized participants, 60 (n = 30/group) completed 8 weeks. The LS mean change from baseline in weight in the 14:10 group was −8.5% (95% CI −9.6 to −7.4; P < 0.001) and −7.1% (−8.3 to −5.8; P < 0.001) in the 12:12 group (between group difference −1.4%; −2.7 to −0.2; P < 0.05). There was a statistically significant LS mean change from baseline to week 8 in FBG in the 14:10 group of −7.6 mg/dl (95% CI −15.1 to −0.1; P < 0.05) but not in the 12:12 group (−3.1 mg/dl, −10.0 to 3.7; P = NS). Both interventions resulted in a larger reduction in FBG in participants with elevated FBG (≥100 mg/dl) at baseline (both P < 0.05).

Conclusions

In participants with obesity who completed 8 weeks of the 14:10 TRE schedule combined with a commercial weight loss program, there was statistically significant and clinically meaningful weight loss and improvements in FBG.

Time-Restricted Eating and Metabolic Syndrome: Current Status and Future Perspectives

Metabolic syndrome (MetS) occurs in ~30% of adults and is associated with increased risk of cardiovascular disease and diabetes mellitus. MetS reflects the clustering of individual cardiometabolic risk factors including central obesity, elevated fasting plasma glucose, dyslipidemia, and elevated blood pressure. Erratic eating patterns such as eating over a prolonged period per day and irregular meal timing are common in patients with MetS. Misalignment between daily rhythms of food intake and circadian timing system can contribute to circadian rhythm disruption which results in abnormal metabolic regulation and adversely impacts cardiometabolic health. Novel approaches which aim at restoring robust circadian rhythms through modification of timing and duration of daily eating represent a promising strategy for patients with MetS. Restricting eating period during a day (time-restricted eating, TRE) can aid in mitigating circadian disruption and improving cardiometabolic outcomes. Previous pilot TRE study of patients with MetS showed the feasibility of TRE and improvements in body weight and fat, abdominal obesity, atherogenic lipids, and blood pressure, which were observed despite no overt attempt to change diet quantity and quality or physical activity. The present article aims at giving an overview of TRE human studies of individuals with MetS or its components, summarizing current clinical evidence for improving cardiometabolic health through TRE intervention in these populations, and presenting future perspectives for an implementation of TRE to treat and prevent MetS. Previous TRE trials laid the groundwork and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy for reducing long-term cardiometabolic risk, providing tools for sustained lifestyle changes and, ultimately, improving overall health in individuals with MetS.

Alternate Day Fasting Combined with a Low Carbohydrate Diet: Effect on Sleep Quality, Duration, Insomnia Severity and Risk of Obstructive Sleep Apnea in Adults with Obesity

Background: Alternate day fasting combined with a low carbohydrate diet (ADF-LC) is an effective weight loss regimen. Whether the weight loss induced by ADF-LC can improve sleep, remains unknown. Objective: This study examined the effect an ADF-LC diet on sleep quality, duration, insomnia severity and the risk of obstructive sleep apnea. Methods: Adults with obesity (n = 31) participated in ADF (600 kcal “fast day”; ad libitum intake “feast day”) with a low-carbohydrate diet (30% carbohydrates, 35% protein, and 35% fat). The 6-month trial consisted of a 3-month weight loss period followed by a 3-month weight maintenance period. Results: Reductions in body weight (−5 ± 1 kg, p < 0.001) and fat mass (−4 ± 1 kg, p < 0.01) were noted during the weight loss period, and these reductions were sustained during the weight maintenance period. Lean mass and visceral fat remained unchanged. The Pittsburgh Sleep Quality Index (PSQI) score indicated poor sleep quality at baseline (6.4 ± 0.7) with no change by month 3 or 6, versus baseline. ISI score indicated subthreshold insomnia at baseline (8.5 ± 1.0), with no change by month 3 or 6, versus baseline. The percent of subjects with high risk of obstructive sleep apnea at baseline was 45%, with no change by month 3 or 6. Wake time, bedtime, and sleep duration remained unchanged. Conclusion: The ADF-LC diet does not impact sleep quality, duration, insomnia severity or the risk of obstructive sleep apnea in adults with obesity.

Effects of time-restricted feeding in weight loss, metabolic syndrome and cardiovascular risk in obese women

BACKGROUND

The increasing prevalence of overweight and obesity among the worldwide population has been associated with a range of adverse health consequences such as Type 2 diabetes and cardiovascular diseases. The metabolic syndrome (MetS) is a cluster of cardiometabolic abnormalities that occur more commonly in overweight individuals. Time-restricted feeding (TRF) is a dietary approach used for weight loss and overall health. TRF may be an option for those subjects who struggle with extreme restriction diets with foods that generally do not belong to an individual's habits.

OBJECTIVE

The purpose of this study was to determine the effect of TRF on body composition and the association of weight loss with metabolic and cardiovascular risks in obese middle-aged women.

METHODS

A non-randomized controlled clinical trial was performed over 3 months in obese women (TRF group, n = 20, BMI 32.53 ± 1.13 vs. Control n = 12, BMI 34.55 ± 1.20). The TRF protocol adopted was 16 h without any energy intake followed by 8 h of normal food intake.

MAIN OUTCOMES AND MEASURES

Anthropometric measurements, body composition, blood biomarkers, cardiovascular risk in 30 years (CVDRisk30y), and quality of life were evaluated at baseline and after the 3 months.

RESULTS

TRF was effective in reducing weight (~ 4 kg), BMI, % of body fat (%BF), waist circumference from baseline without changes in blood biomarkers associated with MetS. TRF promoted a reduction in CVDRisk30y (12%) wich was moderately correlated with %BF (r = 0.62, n = 64, p < 0.001) and %MM (r = - 0.74, n = 64, p < 0.001).

CONCLUSIONS

TRF protocol reduces body weight without changes in biomarkers related to MetS. In addition, the anthropometric evaluation that predicts %BF and %MM could be used as an approach to follow individuals engaged in the TRF regimen since they correlate with cardiovascular risk.

Current Concepts, Opportunities, and Challenges of Gut Microbiome-Based Personalized Medicine in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NALFD) is now a leading cause of chronic liver disease worldwide, in part, as a consequence of rapidly rising levels of obesity and metabolic syndrome and is a major risk factor for cirrhosis, hepatocellular carcinoma, and liver-related mortality. From NAFLD stems a myriad of clinical challenges related to both diagnosis and management. A growing body of evidence suggests an intricate linkage between the gut microbiome and the pathogenesis of NAFLD. We highlight how our current knowledge of the gut-liver axis in NAFLD may be leveraged to develop gut microbiome-based personalized approaches for disease management, including its use as a non-invasive biomarker for diagnosis and staging, as a target for therapeutic modulation, and as a marker of drug response. We will also discuss current limitations of these microbiome-based approaches. Ultimately, a better understanding of microbiota-host interactions in NAFLD will inform the development of novel preventative strategies and precise therapeutic targets.

Time Restricted Eating: A Dietary Strategy to Prevent and Treat Metabolic Disturbances

Time-restricted eating (TRE), a dietary approach limiting the daily eating window, has attracted increasing attention in media and research. The eating behavior in our modern society is often characterized by prolonged and erratic daily eating patterns, which might be associated with increased risk of obesity, diabetes, and cardiovascular diseases. In contrast, recent evidence suggests that TRE might support weight loss, improve cardiometabolic health, and overall wellbeing, but the data are controversial. The present work reviews how TRE affects glucose and lipid metabolism based on clinical trials published until June 2021. A range of trials demonstrated that TRE intervention lowered fasting and postprandial glucose levels in response to a standard meal or oral glucose tolerance test, as well as mean 24-h glucose and glycemic excursions assessed using continuous glucose monitoring. In addition, fasting insulin decreases and improvement of insulin sensitivity were demonstrated. These changes were often accompanied by the decrease of blood triglyceride and cholesterol levels. However, a number of studies found that TRE had either adverse or no effects on glycemic and lipid traits, which might be explained by the different study designs (i.e., fasting/eating duration, daytime of eating, changes of calorie intake, duration of intervention) and study subject cohorts (metabolic status, age, gender, chronotype, etc.). To summarize, TRE represents an attractive and easy-to-adapt dietary strategy for the prevention and therapy of glucose and lipid metabolic disturbances. However, carefully controlled future TRE studies are needed to confirm these effects to understand the underlying mechanisms and assess the applicability of personalized interventions.

Later Meal and Sleep Timing Predicts Higher Percent Body Fat

Accumulating evidence suggests that later timing of energy intake (EI) is associated with increased risk of obesity. In this study, 83 individuals with overweight and obesity underwent assessment of a 7-day period of data collection, including measures of body weight and body composition (DXA) and 24-h measures of EI (photographic food records), sleep (actigraphy), and physical activity (PA, activity monitors) for 7 days. Relationships between body mass index (BMI) and percent body fat (DXA) with meal timing, sleep, and PA were examined. For every 1 h later start of eating, there was a 1.25 (95% CI: 0.60, 1.91) unit increase in percent body fat (False Discovery Rate (FDR) adjusted p value = 0.010). For every 1 h later midpoint of the eating window, there was a 1.35 (95% CI: 0.51, 2.19) unit increase in percent body fat (FDR p value = 0.029). For every 1 h increase in the end of the sleep period, there was a 1.64 (95% CI: 0.56, 2.72) unit increase in percent body fat (FDR p value = 0.044). Later meal and sleep timing were also associated with lower PA levels. In summary, later timing of EI and sleep are associated with higher body fat and lower levels of PA in people with overweight and obesity.

Effect of Dietary Methionine Deficiency Followed by a Re-Feeding Phase on the Hepatic Antioxidant Activities of Lambs

Our objective was to investigate the effect of methionine restriction and resuming supply on liver antioxidant response in lambs. The concentrations of methionine and its metabolites and the expression of the nuclear factor erythroid 2-related factor 2 (Nrf₂), a redox sensitive factor, were detected after methionine restriction treatment for 50 days and methionine supply recovery for 29 days. The expression of glutathione (GSH) S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were characterized at the level of transcription and translation. Methionine restriction can directly change the content of methionine and its metabolites in plasma and liver, and affect the redox state of lambs by activating the Nrf₂ signaling pathway. Liver tissue can adapt to oxidative environment by upregulating the expression of antioxidant enzymes such as GSH-Px and SOD. Moreover, it was found that there was a lag effect in the recovery of metabolism after methionine supplementation.

Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns

The circadian timing system governs daily biological rhythms, synchronising physiology and behaviour to the temporal world. External time cues, including the light-dark cycle and timing of food intake, provide daily signals for entrainment of the central, master circadian clock in the hypothalamic suprachiasmatic nuclei (SCN), and of metabolic rhythms in peripheral tissues, respectively. Chrono-nutrition is an emerging field building on the relationship between temporal eating patterns, circadian rhythms, and metabolic health. Evidence from both animal and human research demonstrates adverse metabolic consequences of circadian disruption. Conversely, a growing body of evidence indicates that aligning food intake to periods of the day when circadian rhythms in metabolic processes are optimised for nutrition may be effective for improving metabolic health. Circadian rhythms in glucose and lipid homeostasis, insulin responsiveness and sensitivity, energy expenditure, and postprandial metabolism, may favour eating patterns characterised by earlier temporal distribution of energy. This review details the molecular basis for metabolic clocks, the regulation of feeding behaviour, and the evidence for meal timing as an entraining signal for the circadian system in animal models. The epidemiology of temporal eating patterns in humans is examined, together with evidence from human intervention studies investigating the metabolic effects of morning compared to evening energy intake, and emerging chrono-nutrition interventions such as time-restricted feeding. Chrono-nutrition may have therapeutic application for individuals with and at-risk of metabolic disease and convey health benefits within the general population.

Identification of SCARA3 with potential roles in metabolic disorders

Obesity is characterized by the expansion of adipose tissue which is partially modulated by adipogenesis. In the present study, we identified five differentially expressed genes by incorporating two adipogenesis-related datasets from the GEO database and their correlation with adipogenic markers. However, the role of scavenger receptor class A member 3 (SCARA3) in obesity-related disorders has been rarely reported. We found that Scara3 expression in old adipose tissue-derived mesenchymal stem cells (Ad-MSCs) was lower than it in young Ad-MSCs. Obese mice caused by deletion of the leptin receptor gene (db/db) or by a high-fat diet both showed reduced Scara3 expression in inguinal white adipose tissue. Moreover, hypermethylation of SCARA3 was observed in patients with type 2 diabetes and atherosclerosis. Data from the CTD database indicated that SCARA3 is a potential target for metabolic diseases. Mechanistically, JUN was predicted as a transcriptional factor of SCARA3 in different databases which is consistent with our further bioinformatics analysis. Collectively, our study suggested that SCARA3 is potentially associated with age-related metabolic dysfunction, which provided new insights into the pathogenesis and treatment of obesity as well as other obesity-associated metabolic complications.

Intermittent fasting as a nutrition approach against obesity and metabolic disease

PURPOSE OF REVIEW

Intermittent fasting has been proposed as a potential nutrition approach against obesity and metabolic disease. Although data from studies in rodents convincingly support the antiobesity and cardiometabolic benefits of intermittent fasting, its effects in human health are still debatable.

RECENT FINDINGS

Recent studies have examined the effect of two intermittent fasting approaches, that is, alternate day fasting (ADF) and time-restricted eating (TRE), on weight loss and cardiometabolic risk factors. ADF seems to be an equally effective weight loss approach to caloric restriction, but adherence to ADF is more challenging. ADF improves cardiometabolic risk factors, whereas it may have superior metabolic benefits compared to caloric restriction in people with insulin resistance. TRE with ad libitum food intake is well tolerated and induces 2-4% weight loss in approximatively 3 months. Additionally, TRE may have metabolic benefits particularly in people with metabolically abnormal obesity even without weight loss.

SUMMARY

Intermittent fasting is a promising nutritional approach against obesity and its related metabolic diseases. Further research is needed to: i) establish the long-term effectiveness of TRE in weight loss and metabolic health, ii) improve the long-term adherence to ADF and investigate its weight loss independent effects in metabolic health, and iii) determine the mechanisms underlying the potential cardiometabolic benefits of intermittent fasting in humans.

Time-Restricted Eating as a Nutrition Strategy for Individuals with Type 2 Diabetes: A Feasibility Study

Individuals with type 2 diabetes (T2D) require a long-term dietary strategy for blood glucose management and may benefit from time-restricted eating (TRE, where the duration between the first and last energy intake is restricted to 8–10 h/day). We aimed to determine the feasibility of TRE for individuals with T2D. Participants with T2D (HbA1c >6.5 to <9%, eating window >12 h/day) were recruited to a pre-post, non-randomised intervention consisting of a 2-week Habitual period to establish baseline dietary intake, followed by a 4-weeks TRE intervention during which they were instructed to limit all eating occasions to between 10:00 and 19:00 h on as many days of each week as possible. Recruitment, retention, acceptability, and safety were recorded throughout the study as indicators of feasibility. Dietary intake, glycaemic control, psychological well-being, acceptability, cognitive outcomes, and physiological measures were explored as secondary outcomes. From 594 interested persons, and 27 eligible individuals, 24 participants enrolled and 19 participants (mean ± SD; age: 50 ± 9 years, BMI: 34 ± 5 kg/m², HbA1c: 7.6 ± 1.1%) completed the 6-week study. Overall daily dietary intake did not change between Habitual (~8400 kJ/d; 35% carbohydrate, 20% protein, 41% fat, 1% alcohol) and TRE periods (~8500 kJ/d; 35% carbohydrate, 19% protein, 42% fat, 1% alcohol). Compliance to the 9 h TRE period was 72 ± 24% of 28 days (i.e., ~5 days/week), with varied adherence (range: 4–100%). Comparisons of adherent vs. non-adherent TRE days showed that adherence to the 9-h TRE window reduced daily energy intake through lower absolute carbohydrate and alcohol intakes. Overall, TRE did not significantly improve measures of glycaemic control (HbA1c −0.2 ± 0.4%; p = 0.053) or reduce body mass. TRE did not impair or improve psychological well-being, with variable effects on cognitive function. Participants described hunger, daily stressors, and emotions as the main barriers to adherence. We demonstrate that 4-weeks of TRE is feasible and achievable for these individuals with T2D to adhere to for at least 5 days/week. The degree of adherence to TRE strongly influenced daily energy intake. Future trials may benefit from supporting participants to incorporate TRE in regular daily life and to overcome barriers to adherence.

Perturbation of the circadian clock and pathogenesis of NAFLD

All living organisms including humans, experience changes in the light exposure generated by the Earth's rotation. In anticipation of this unavoidable geo-physical variability, and to generate an appropriate biochemical response, species of many phyla, including mammals have evolved a nearly 24-hour endogenous timing device known as the circadian clock (CC), which is self-sustained, cell autonomous and is present in every cell type. At the heart of the 'clock' functioning resides the CC-oscillator, an elegantly designed transcriptional-translational feedback system. Notably, the core components of the CC-oscillator not only drive daily rhythmicity of their own synthesis, but also generate circadian phase-specific variability in the expression levels of thousands of target genes through transcriptional, post-transcriptional and post-translational mechanisms. Thereby, this 'clock'-system provides proper chronological coordination in the functioning of cells, tissues and organs. The CC governs many physiologically critical functions. Among these functions, the key role of the CC in maintaining metabolic homeostasis deserves special emphasis. Indeed, the several features of the modern lifestyle (e.g. travel-induced jet lag, rotating shift work, energy-dense food) which, force disruption of circadian rhythms have recently emerged as a major driver to global health problems like obesity, cardiovascular disease and metabolic liver disease such as non-alcoholic fatty liver disease (NAFLD). Here we review, the CC-dependent pathways in different tissues which play critical roles in mediating several critical metabolic functions under physiological conditions and discuss their impact for the development of metabolic disease with a focus on the liver.

The effect of caloric restriction and fasting on cancer

Cancer is one of the most frequent causes of worldwide death and morbidity and is a major public health problem. Although, there are several widely used treatment methods including chemo-, immune- and radiotherapies, these mostly lack sufficient efficiency and induce toxicities in normal surrounding tissues. Thus, finding new approaches to mitigate side effects and potentially accelerate treatment is paramount. In line with this, increasing preclinical evidence indicates that caloric restriction (CR) and fasting might have anticancer effects by reducing tumor progression, enhancing death of cancer cells, and elevating the effectiveness and tolerability of chemo- and radiotherapies. Nonetheless, clinical studies assessing the potential of CR and fasting in cancer are scarce and inconsistent, and more investigations are still required to clarify their effect in different aspects of cancer treatment. In this review, we have summarized the findings of preclinical and clinical studies of CR and fasting with respect to efficacy and on the adverse effects of standard cancer treatments.