Chrono-nutrition for the prevention and treatment of obesity and type 2 diabetes: from mice to men

The impact of eating behaviors during COVID-19 in health-care workers: A conditional process analysis of eating, affective disorders, and PTSD

Objective

The incidence of post-traumatic stress disorder (PTSD) increased among healthcare workers (HCWs) during the outbreak of COVID-19. The purpose of this study was to examine the relationship between eating behavior and PTSD, considering the mediation effect of anxiety, depression and sleep.

Methods

A total of 101 HCWs completed a survey. The Food-Frequency Questionnaires (FFQ) were used to evaluate the diet. A special survey was conducted on the eating time of each shift mode. The PTSD Checklist-Civilian Version (PCL-C), Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), Pittsburgh Sleep Quality Index (PSQI), and Morning-Evening Questionnaire (MEQ) were utilized to assess clinical symptoms.

Results

There was a statistically significant correlation between the night shift eat midpoint (NEMP) and PTSD symptoms, anxiety and depression as significant mediators. The last meal jet lag between night shift and day shift (NDLM) was related to PTSD symptoms significantly, and sleep and anxiety were significant mediators. The relationship between animal-based protein pattern and PTSD symptoms was statistically significant, and anxiety was the significant mediator.

Conclusions

The earlier the HCWs eat in the night shift, the lighter the symptoms of PTSD. This is mediated by improving anxiety, depression and sleep disorder. Furthermore, the consumption of animal protein could reduce symptoms of PTSD by improving anxiety.

Time-restricted eating and exercise training improve HbA1c and body composition in women with overweight/obesity: A randomized controlled trial

Diet modification and exercise training are primary lifestyle strategies for obesity management, but poor adherence rates limit their effectiveness. Time-restricted eating (TRE) and high-intensity interval training (HIIT) improve cardiometabolic health in at-risk individuals, but whether these two interventions combined induce superior improvements in glycemic control than each individual intervention is not known. In this four-armed randomized controlled trial (ClinicalTrials.gov NCT04019860), we determined the isolated and combined effects of 7 weeks of TRE (≤10-h daily eating window, with ad libitum energy intake) and HIIT (three exercise sessions per week), compared with a non-intervention control group, on glycemic control and secondary cardiometabolic outcomes in 131 women (36.2 ± 6.2 years) with overweight/obesity. There were no statistically significant effects after isolated TRE, HIIT, or a combination (TREHIIT) on glucose area under the curve during an oral glucose tolerance test (the primary outcome) compared with the control group (TRE, -26.3 mmol/L; 95% confidence interval [CI], -82.3 to 29.7, p = 0.36; HIIT, -53.8 mmol/L; 95% CI, -109.2 to 1.6, p = 0.057; TREHIIT, -41.3 mmol/L; 95% CI, -96.4 to 13.8, p = 0.14). However, TREHIIT improved HbA1c and induced superior reductions in total and visceral fat mass compared with TRE and HIIT alone. High participant adherence rates suggest that TRE, HIIT, and a combination thereof may be realistic diet-exercise strategies for improving markers of metabolic health in women at risk of cardiometabolic disease.

Linking Depressive and Anxiety Symptoms with Diet Quality of University Students: A Cross-Sectional Study during the COVID-19 Pandemic in India

This study examines the association of depressive and anxiety symptoms with diet quality among university students while controlling for different demographic and other health and lifestyle factors. This cross-sectional study was carried out between April 2021 and June 2021 among a total of 440 (unweighted) university students. Diet quality was assessed using a 10-item mini-dietary assessment index tool. The depressive and anxiety symptoms of participants were measured using the validated Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder (GAD-7) scale, respectively. Multivariable logistic regression and mediation analyses were performed. In this study, 61.1% (95% CI: 56.6% to 65.7%) of university students' diet quality was good during the COVID-19 pandemic. Being a post-graduate student, an urban resident, having no depressive (AOR = 2.15, 95% CI: 1.20 to 3.84) and anxiety symptoms (AOR = 1.96, 95% CI: 1.07 to 3.59), no changes or improvement in appetite, and no changes in sleep duration were significantly associated with good diet quality among our study participants. Depressive and anxiety symptoms during COVID-19 had a significant effect on the diet quality of university students. Future public health policies need to be focused on improving the mental health and well-being of students particularly during pandemic situations to enhance their diet quality.

Timed restricted feeding cycles drive daily rhythms in female rats maintained in constant light but only partially restore the estrous cycle

Light at night is an emergent problem for modern society. Rodents exposed to light at night develop a loss of circadian rhythms, which leads to increased adiposity, altered immune response, and increased growth of tumors. In female rats, constant light (LL) eliminates the estrous cycle leading to a state of persistent estrus. The suprachiasmatic nucleus (SCN) drives circadian rhythms, and it interacts with the neuroendocrine network necessary for reproductive function. Timed restricted feeding (RF) exerts a powerful entraining influence on the circadian system, and it can influence the SCN activity and can restore rhythmicity or accelerate re-entrainment in experimental conditions of shift work or jet lag. The present study explored RF in female rats exposed to LL, with the hypothesis that this cyclic condition can rescue or prevent the loss of daily rhythms and benefit the expression of the estrous cycle. Two different feeding schedules were explored: 1. A 12-h food/12-h fasting schedule applied to arrhythmic rats after 3 weeks in LL, visualized as a rescue strategy (LL + RFR, 3 weeks), or applied simultaneously with the first day of LL as a preventive strategy (LL + RFP, 6 weeks). 2. A 12-h window of food intake with food given in four distributed pulses (every 3 h), applied after 3 weeks in LL, as a rescue strategy (LL + PR, 3 weeks) or applied simultaneously with the first day of LL as a preventive strategy (LL + PP, 6 weeks). Here, we present evidence that scheduled feeding can drive daily rhythms of activity and temperature in rats exposed to LL. However, the protocol of distributed feeding pulses was more efficient to restore the day–night activity and core temperature as well as the c-Fos day–night change in the SCN. Likewise, the distributed feeding partially restored the estrous cycle and the ovary morphology under LL condition. Data here provided indicate that the 12-h feeding/12-h fasting window determines the rest-activity cycle and can benefit directly the circadian and reproductive function. Moreover, this effect is stronger when food is distributed along the 12 h of subjective night.

Is time-restricted eating a robust eating regimen during periods of disruptions in daily life? A qualitative study of perspectives of people with overweight during COVID-19

Background

Time-restricted eating (TRE) has been suggested as a feasible dietary strategy in individuals with overweight. Disruptions in daily life e.g., severe illness can affect engagement in lifestyle interventions to obtain healthier body weight. This study examined if and how the engagement with TRE among people with overweight was affected by the Danish COVID-19 lockdowns as an example of disruptions in daily life.

Methods

Fifteen participants with overweight enrolled in a TRE intervention, i.e. restricting all eating and drinking except water to the same daily ten-hour window, were interviewed about their experiences and engagement with TRE during COVID-19 lockdowns. Interviews were semi-structured and conducted by phone or face-to-face with safe social distancing. Data analysis was grounded in a reflexive thematic analysis approach.

Results

Daily life rhythms were disrupted by lockdowns by preventing participants from performing ordinary daily activities such as going to work, socialising, eating out or exercising. For some, this challenged their TRE engagement, while most were able to undertake the TRE eating window but reported increased snacking and consumption of take-away food within their eating window. For all, exercise habits became unhealthier. The negative impact on TRE engagement primarily occurred during daytime, as social distancing made it easier to engage with TRE during evenings.

Conclusions

This study showed that even people highly motivated to obtain healthier lifestyles practices struggled to maintain engagement with healthy behaviours, whereas sticking to the TRE window was manageable during COVID-19. TRE as a weight loss strategy was challenged which calls for more attention to supporting people in daily life to obtain healthier practices, also in case of periods of other disruptions such as divorce, serious illness etc.

Chronotype, chrononutrition and glucose tolerance among prediabetic individuals: research protocol for a prospective longitudinal study Chrono-DM™

BACKGROUND

Chronotype and chrononutrition, both are emerging research interests in nutritional epidemiology. However, its association with glycemic control in the Asia population is less clear. A better understanding of how activity/eating time can influence glucose levels in Asian prediabetic individuals may improve strategies for blood glucose control in Asian countries. The present paper describes the research protocol which aims to determine the associations of chronotype and chrononutrition with glucose tolerance among Malaysian prediabetic individuals.

METHODS

This is a prospective longitudinal study named Chrono-DM™, that targets to recruit 166 newly diagnosed prediabetic individuals from the community clinics in Malacca, Malaysia. Respondents will be followed-up for 6 months: (1) baseline (1^st oral glucose tolerance test (OGTT)); (2) second visit (at 3^rd month); and (3) third visit (2^nd OGTT at 6^th month). Data collection includes sociodemographic and anthropometry measurements (weight, height, body fat, visceral fat, waist and hip circumference). Dietary intake and meal timing are collected using the 3-day dietary record while data on sleep pattern, light exposure, chronotype and chrononutrition will be collected using validated questionnaires. Physical activity will be recorded using a validated IPAQ questionnaire and pedometer during periods of using continuous glucose monitoring (CGM) sensor. CGM, fasting blood sugar (FBS), OGTT and HbA1c are performed to assess glycemic outcomes.

DISCUSSION

The Chrono-DM™ study represents a novel approach to determining the association of chronotype and chrononutrition with glycemic control. We anticipate that this study will not only review the association of chronotype with glycemia measure but also provide greater insight into optimal meal time for glycemic control among prediabetic individuals in the Asian population.

TRIAL REGISTRATION

NCT05163964 (Clinicaltrial.gov). Trial registration date:  20 December 2021.

Nutrition for precision health: The time is now

Precision nutrition has emerged as a boiling area of nutrition research, with a particular focus on revealing the individual variability in response to diets that is determined mainly by the complex interactions of dietary factors with the multi-tiered "omics" makeups. Reproducible findings from the observational studies and diet intervention trials have lent preliminary but consistent evidence to support the fundamental role of gene-diet interactions in determining the individual variability in health outcomes including obesity and weight loss. Recent investigations suggest that the abundance and diversity of the gut microbiome may also modify the dietary effects; however, considerable instability in the results from the microbiome research has been noted. In addition, growing studies suggest that a complicated multiomics algorithm would be developed by incorporating the genome, epigenome, metabolome, proteome, and microbiome in predicting the individual variability in response to diets. Moreover, precision nutrition would also scrutinize the role of biological (circadian) rhythm in determining the individual variability of dietary effects. The evidence gathered from precision nutrition research will be the basis for constructing precision health dietary recommendations, which hold great promise to help individuals and their health care providers create precise and effective diet plans for precision health in the future.

The Association of Consumption Time for Food With Cardiovascular Disease and All-Cause Mortality Among Diabetic Patients

AIMS

This study aims to investigate whether food intake time across 3 meals is associated with long-term survival among the people with diabetes.

MATERIALS AND METHODS

This study included 4642 diabetic patients participating in the National Health and Nutrition Examination Survey from 2003 to 2014. Food consumed across a day including the forenoon, afternoon, and evening was divided into quantiles based on their distribution. Cox proportional hazards regression models were used to analyze the survival relationship between food intakes time and mortality.

RESULTS

In the forenoon, compared to the participants in the lowest quantile of potato and starchy vegetable, participants in the highest quantile had lower mortality risk of cardiovascular disease (CVD) [hazard ratio (HR)potato = 0.46, 95% CI 0.24-0.89; HRstarchy-vegetable = 0.32, 95% CI 0.15-0.72]. In the afternoon, participants who consumed whole grain had lower mortality of CVD (HRwhole grain = 0.67, 95% CI 0.48-0.95). In the evening, the highest quantile of dark vegetable and milk intake is related to lower mortality risk of CVD (HRdark vegetable = 0.55, 95% CI 0.35-0.87; HRmilk = 0.56, 95% CI 0.36-0.88) and all-cause mortality (HRmilk = 0.71, 95% CI 0.54-0.92), whereas participants in the highest quantile of intakes of processed meat are more likely to die due to CVD (HRprocessed-meat = 1.74, 95% CI 1.07-2.82). Isocalorically switching 0.1 serving potato or starchy vegetable consumed in the afternoon or evening to the forenoon, 0.1 serving dark vegetable consumed in the afternoon to the evening, and 0.1 serving whole grain consumed in the forenoon to the afternoon reduced the risk of CVD mortality.

CONCLUSIONS

Higher intake of potato or starchy vegetable in forenoon, whole grain in the afternoon, and dark vegetable and milk in the evening and lower intake of processed meat in the evening was associated with better long-term survival in people with diabetes.

Is Time-Restricted Eating Safe in the Treatment of Type 2 Diabetes?-A Review of Intervention Studies

Time-restricted eating (TRE) has been shown to improve body weight and glucose metabolism in people at high risk of type 2 diabetes. However, the safety of TRE in the treatment of type 2 diabetes is unclear. We investigated the safety of TRE interventions in people with type 2 diabetes by identifying published and ongoing studies. Moreover, we identified the commonly used antidiabetic drugs and discussed the safety of TRE in people with type 2 diabetes considering the use of these drugs. In addition, we addressed the research needed before TRE can be recommended in the treatment of type 2 diabetes. A literature search was conducted to identify published (MEDLINE PubMed) and ongoing studies (ClinicalTrials.gov) on TRE in people with type 2 diabetes. To assess the usage of antidiabetic drugs and to discuss pharmacodynamics and pharmacokinetics in a TRE context, the most used antidiabetic drugs were identified and analysed. Statistics regarding sale of pharmaceuticals were obtained from MEDSTAT.DK which are based on data from the national Register of Medicinal Product Statistics, and from published studies on medication use in different countries. Four published studies investigating TRE in people with type 2 diabetes were identified as well as 14 ongoing studies. The completed studies suggested that TRE is safe among people with type 2 diabetes. Common antidiabetic drugs between 2010 and 2019 were metformin, insulin, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, sulfonylureas, and sodium-glucose cotransporter-2 inhibitors. Existing studies suggest that TRE is not associated with major safety issues in people with type 2 diabetes as long as medication is monitored and adjusted. However, because of low generalisability of the few studies available, more studies are needed to make concrete recommendations regarding efficacy and safety of TRE in people with type 2 diabetes.

The effects of macronutrients composition on hormones and substrates during a meal tolerance test in drugnaive and sitagliptin-treated individuals with type 2 diabetes: a randomized crossover study

Objective

To evaluate the effect of sitagliptin treatment in early type 2 diabetes mellitus (T2DM) and the impact of different macronutrient compositions on hormones and substrates during meal tolerance tests (MTT).

Methods

Half of the drug-naive patients with T2DM were randomly assigned for treatment with 100 mg of sitagliptin, q.d., or placebo for 4 weeks and then submitted to 3 consecutive MTT intercalated every 48 h. The MTTs differed in terms of macronutrient composition, with 70% of total energy from carbohydrates, proteins, or lipids. After 4 weeks of washout, a crossover treatment design was repeated. Both patients and researchers were blinded, and a repeated-measures ANOVA was employed for statistical analysis.

Results

Sitagliptin treatment reduced but did not normalize fasting and post-meal glucose values in the three MTTs, with lowered area-under-glucose-curve values varying from 7% to 15%. The sitagliptin treatment also improved the insulinogenic index (+86%) and the insulin/glucose (+25%), glucagon-like peptide-1/glucose (+46%) incremental area under the curves. Patients with early T2DM maintained the lowest glucose excursion after a protein- or lipid-rich meal without any major change in insulin, C-peptide, glucagon, or NEFA levels.

Conclusion

We conclude that sitagliptin treatment is tolerable and contributes to better control of glucose homeostasis in early T2DM, irrespective of macronutrient composition. The blood glucose excursion during meal ingestion is minimal in protein- or fat-rich meals, which can be a positive ally for the management of T2DM. Clinical trial no: NCT00881543.

The combined therapy of mesenchymal stem cell transplantation and resveratrol for diabetes: Future applications and challenges

Diabetes mellitus (DM) is a worldwide chronic epidemic disease of impaired glucose metabolism. Transplantation of mesenchymal stem cells (MSCs) is considered a promising emerging treatment strategy for diabetes. However, the harsh internal environment of DM patients can inhibit the treatment effects of transplanted MSCs. Fortunately, this adverse effect can be reversed by resveratrol (Res). Therefore, we investigated and summarized relevant studies on the combined treatment of diabetes with MSCs and resveratrol. This review presents the therapeutic effects of this combination therapy strategy on DM in glycemic control, anti-inflammatory, anti-oxidative stress and anti-fibrotic. Moreover, this review explained the mechanisms of MSCs and resveratrol in diabetes treatment from 3 aspects, including promoting cell survival and inhibiting apoptosis, inhibiting histiocyte fibrosis, and improving glucose metabolism. These findings help to understand in-depth mechanisms of the treatment of DM and help to propose a potential treatment strategy for DM and its complications.

What happens after a weight loss intervention? A qualitative study of drivers and challenges of maintaining time-restricted eating among people with overweight at high risk of type 2 diabetes

Time-restricted eating (TRE)¹ has been conceptualised as a strategy for achieving weight loss and improving metabolic health, but limited knowledge exists about how people can maintain TRE in daily life. This study examined how TRE was maintainable in daily life after a three-month intervention (the RESET study) in which participants were encouraged to consume all food and beverages except water within a 10-hour daily window. Specifically, we examined TRE maintenance patterns across participants, including drivers and challenges for maintenance success. A qualitative longitudinal study was conducted, and twenty participants with overweight at high risk of type 2 diabetes were interviewed using a semi-structured interview guide at the end of the intervention and after a three-month follow-up period. Data were analysed longitudinally in two steps inspired by a pattern-oriented longitudinal analysis approach. Seven participants maintained a strict 10-hour window, ten maintained an adjusted TRE regimen (e.g., taking days off), and three did not attempt maintenance. Maintenance drivers included consistent daily rhythms and regular meal patterns, subjective experiences (e.g., feeling healthier), making flexible adjustments to the TRE regimen, family support and avoiding feelings of guilt. Maintenance challenges included social evening events, inconsistent daily rhythms and eating patterns, preoccupation with losing weight, lack of family support and self-blame. TRE was manageable for most participants; however, personalised support for adjusting TRE to daily life is needed to ensure long-term maintenance. Future studies should explore the effectiveness of a personalised TRE concept to determine the usefulness of TRE in real-life settings.

Perspective: Time-Restricted Eating-Integrating the What with the When

Time-restricted eating (TRE) is a popular dietary strategy that emphasizes the timing of meals in alignment with diurnal circadian rhythms, permitting ad libitum energy intake during a restricted (∼8-10 h) eating window each day. Unlike energy-restricted diets or intermittent fasting interventions that focus on weight loss, many of the health-related benefits of TRE are independent of reductions in body weight. However, TRE research to date has largely ignored what food is consumed (i.e., macronutrient composition and energy density), overlooking a plethora of past epidemiological and interventional dietary research. To determine some of the potential mechanisms underpinning the benefits of TRE on metabolic health, future studies need to increase the rigor of dietary data collected, assessed, and reported to ensure a consistent and standardized approach in TRE research. This Perspective article provides an overview of studies investigating TRE interventions in humans and considers dietary intake (both what and when food is eaten) and their impact on selected health outcomes (i.e., weight loss, glycemic control). Integrating existing dietary knowledge about what food is eaten with our recent understanding on when food should be consumed is essential to optimize the impact of dietary strategies aimed at improving metabolic health outcomes.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7-10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Atlas of exercise metabolism reveals time-dependent signatures of metabolic homeostasis

Tissue sensitivity and response to exercise vary according to the time of day and alignment of circadian clocks, but the optimal exercise time to elicit a desired metabolic outcome is not fully defined. To understand how tissues independently and collectively respond to timed exercise, we applied a systems biology approach. We mapped and compared global metabolite responses of seven different mouse tissues and serum after an acute exercise bout performed at different times of the day. Comparative analyses of intra- and inter-tissue metabolite dynamics, including temporal profiling and blood sampling across liver and hindlimb muscles, uncovered an unbiased view of local and systemic metabolic responses to exercise unique to time of day. This comprehensive atlas of exercise metabolism provides clarity and physiological context regarding the production and distribution of canonical and novel time-dependent exerkine metabolites, such as 2-hydroxybutyrate (2-HB), and reveals insight into the health-promoting benefits of exercise on metabolism.

Chrononutrition in Cardiometabolic Health

In recent years, a healthy balanced diet together with weight reduction has risen to the forefront of minimizing the impact of cardiovascular disease. There is evidence that metabolic processes present circadian rhythmicity. Moreover, the timing of food consumption exerts a powerful influence on circadian rhythms. In this context, the subject of chrononutrition, described as the alignment of timing of food intake to the rhythms imposed by the circadian clock, has attracted considerable interest for possible beneficial effects on cardiovascular health. Current human studies suggest that chrononutrition-based dietary interventions could reduce the risk for cardiovascular disease by improving weight control, hypertension, dyslipidemia, and diabetes. However, meta-analysis of randomized control trials in this topic present varying and somehow conflicting results. Even the traditional association of breakfast skipping with adverse cardiovascular outcomes is nowadays controversial. Therefore, long-term and fairly consistent studies on the effect of chrononutrition on cardiovascular outcomes are needed. The purpose of this review is to provide concise evidence of the most recent literature involving the effects of chrononutrition and the specific chrononutrition-based dietary interventions, in particular time-restricted eating, on body weight and other cardiovascular disease risk factors.

Perspective: A Framework for Addressing Dynamic Food Consumption Processes

The study of food consumption, diet, and related concepts is motivated by diverse goals, including understanding why food consumption impacts our health, and why we eat the foods we do. These varied motivations can make it challenging to define and measure consumption, as it can be specified across nearly infinite dimensions-from micronutrients to carbon footprint to food preparation. This challenge is amplified by the dynamic nature of food consumption processes, with the underlying phenomena of interest often based on the nature of repeated interactions with food occurring over time. This complexity underscores a need to not only improve how we measure food consumption but is also a call to support theoreticians in better specifying what, how, and why food consumption occurs as part of processes, as a prerequisite step to rigorous measurement. The purpose of this Perspective article is to offer a framework, the consumption process framework, as a tool that researchers in a theoretician role can use to support these more robust definitions of consumption processes. In doing so, the framework invites theoreticians to be a bridge between practitioners who wish to measure various aspects of food consumption and methodologists who can develop measurement protocols and technologies that can support measurement when consumption processes are clearly defined. In the paper we justify the need for such a framework, introduce the consumption process framework, illustrate the framework via a use case, and discuss existing technologies that enable the use of this framework and, by extension, more rigorous study of consumption. This consumption process framework demonstrates how theoreticians could fundamentally shift how food consumption is defined and measured towards more rigorous study of what, how, and why food is eaten as part of dynamic processes and a deeper understanding of linkages between behavior, food, and health.

A Growing Link between Circadian Rhythms, Type 2 Diabetes Mellitus and Alzheimer's Disease

Type 2 diabetes mellitus (T2DM) patients are at a higher risk of developing Alzheimer's disease (AD). Mounting evidence suggests the emerging important role of circadian rhythms in many diseases. Circadian rhythm disruption is considered to contribute to both T2DM and AD. Here, we review the relationship among circadian rhythm disruption, T2DM and AD, and suggest that the occurrence and progression of T2DM and AD may in part be associated with circadian disruption. Then, we summarize the promising therapeutic strategies targeting circadian dysfunction for T2DM and AD, including pharmacological treatment such as melatonin, orexin, and circadian molecules, as well as non-pharmacological treatments like light therapy, feeding behavior, and exercise.

Effects of Early vs. Late Time-Restricted Eating on Cardiometabolic Health, Inflammation, and Sleep in Overweight and Obese Women: A Study Protocol for the ChronoFast Trial

Background: Time-restricted eating is a promising dietary strategy for weight loss, glucose and lipid metabolism improvements, and overall well-being. However, human studies demonstrated contradictory results for the restriction of food intake to the beginning (early TRE, eTRE) or to the end of the day (late TRE, lTRE) suggesting that more carefully controlled studies are needed.

Objective: The aim of the ChronoFast trial study is to determine whether eTRE or lTRE is a better dietary approach to improve cardiometabolic health upon minimized calorie deficits and nearly stable body weight.

Methods: Here, we present the study protocol of the randomized cross-over ChronoFast clinical trial comparing effects of 2 week eTRE (8:00 to 16:00 h) and lTRE (13:00 to 21:00 h) on insulin sensitivity and other glycemic traits, blood lipids, inflammation, and sleep quality in 30 women with overweight or obesity and increased risk of type 2 diabetes. To ensure timely compliance and unchanged dietary composition, and to minimize possible calorie deficits, real-time monitoring of dietary intake and body weight using a smartphone application, and extensive nutritional counseling are performed. Continuous glucose monitoring, oral glucose tolerance test, 24 h activity tracking, questionnaires, and gene expression analysis in adipose tissue and blood monocytes will be used for assessment of study outcomes.

Discussion: The trial will determine whether eTRE or lTRE is more effective to improve cardiometabolic health, elucidate underlying mechanisms, and contribute to the development of recommendations for medical practice and the wider population.

Clinical Trial Registration:www.ClinicalTrials.gov, Identifier [NCT04351672]

Daytime eating prevents internal circadian misalignment and glucose intolerance in night work

Night work increases diabetes risk. Misalignment between the central circadian “clock” and daily behaviors, typical in night workers, impairs glucose tolerance, likely due to internal misalignment between central and peripheral circadian rhythms. Whether appropriate circadian alignment of eating can prevent internal circadian misalignment and glucose intolerance is unknown. In a 14-day circadian paradigm, we assessed glycemic control during simulated night work with either nighttime or daytime eating. Assessment of central (body temperature) and peripheral (glucose and insulin) endogenous circadian rhythms happened during constant routine protocols before and after simulated night work. Nighttime eating led to misalignment between central and peripheral (glucose) endogenous circadian rhythms and impaired glucose tolerance, whereas restricting meals to daytime prevented it. These findings offer a behavioral approach to preventing glucose intolerance in shift workers.

Circadian Rhythms, Disease and Chronotherapy

Circadian clocks are biological timing mechanisms that generate 24-h rhythms of physiology and behavior, exemplified by cycles of sleep/wake, hormone release, and metabolism. The adaptive value of clocks is evident when internal body clocks and daily environmental cycles are mismatched, such as in the case of shift work and jet lag or even mistimed eating, all of which are associated with physiological disruption and disease. Studies with animal and human models have also unraveled an important role of functional circadian clocks in modulating cellular and organismal responses to physiological cues (ex., food intake, exercise), pathological insults (e.g. virus and parasite infections), and medical interventions (e.g. medication). With growing knowledge of the molecular and cellular mechanisms underlying circadian physiology and pathophysiology, it is becoming possible to target circadian rhythms for disease prevention and treatment. In this review, we discuss recent advances in circadian research and the potential for therapeutic applications that take patient circadian rhythms into account in treating disease.

Ritmi circadiani e variabili metaboliche

I ritmi circadiani sono influenzati da numerose variabili correlate allo stile di vita, soprattutto in relazione ai ritmi imposti dalla società moderna, e vengono profondamente alterati da diverse condizioni patologiche. La fisiologia circadiana è organizzata in modo complesso e integrato; molti dei fattori che sincronizzano il sistema sono a loro volta influenzati e regolati da diversi assi ormonali. Parallelamente, i disturbi del ritmo circadiano derivano da input non ottimali dei fattori sincronizzanti o da condizioni patologiche, e le conseguenze determinano un impatto significativo in diverse condizioni, quali l’obesità e i disturbi del sonno. Durante l’attuale emergenza COVID-19 sono stati registrati crescenti tassi di alterazioni del sonno, complici la preoccupazione diffusa, un comportamento alimentare alterato e la difficoltà per molti, durante il lockdown, nel mantenere ritmi di vita regolari (Barrea et al. in J Transl Med 18:1–11, 2020). Le misure di intervento che si sono mostrate più promettenti contro la desincronizzazione circadiana sono quelle che agiscono sullo stile di vita, basate sul recupero di un corretto ritmo del sonno, la corretta esposizione alla luce solare, l’idonea distribuzione dei pasti e del timing alimentare e lo svolgimento di un’adeguata attività fisica.

Do Temporal Eating Patterns Differ in Healthy versus Unhealthy Overweight/Obese Individuals?

This study examined whether the temporal patterns of energy and macronutrient intake in early and late eating windows were associated with metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) among non-shift workers. A total of 299 overweight/obese non-shift workers (Age: 40.3 ± 6.9 years; 73.6% women; BMI: 31.7 ± 5.0 kg/m²) were recruited in the Klang Valley area of Malaysia. The biochemical parameters were determined from fasting blood samples, whereas information on dietary intake and timing was obtained from a 7-day diet history questionnaire. The midpoint of eating was used to determine the early and late windows. Compared to MHO non-shift workers (n = 173), MUO non-shift workers (n = 126) had lower energy intake from carbohydrates and protein during the early window. In contrast, MUO participants had greater energy intake from carbohydrates and fat during the late window. Participants with unhealthy metabolic status (regardless of their chronotypes) had similar temporal patterns of energy intake characterized by smaller energy intake during the early window and greater energy intake during the late window compared with participants with healthier metabolic status. Overall, the lowest percentile of energy intake during the early window was associated with an increased risk of MUO, after adjustment for potential confounders [odds ratio (OR) = 4.30, 95% confidence interval (CI) 1.41-13.11]. The greater the energy intake during the late window, the greater the risk of MUO (OR = 2.38, 95% CI 1.11-5.13) (OR = 2.33, 95% CI 1.03-5.32) (OR = 4.45, 95% CI 1.71-11.56). In summary, consuming less energy earlier in the day and more energy and carbohydrate later in the day was associated with a greater risk of MUO. Thus, a prospective study is needed to explore the potential role of chrono-nutrition practices in modifying risk factors to delay the transition of MHO to MUO.

Time-Restricted Feeding during Puberty Ameliorates Adiposity and Prevents Hepatic Steatosis in a Mouse Model of Childhood Obesity

BACKGROUND

Time restricted feeding (TRF) refers to dietary interventions in which food access is limited during a specific timeframe of the day. TRFs have proven useful in improving metabolic health in adult subjects with obesity. Their beneficial effects are mediated, in part, through modulating the circadian rhythm. Nevertheless, the translation of these dietary interventions onto obese/overweight children and adolescents remains uncharacterized. The objective of this study is to explore the feasibility of temporal dietary interventions for improving metabolic health in the context of childhood obesity.

METHODS

We have previously developed a mouse model of early adiposity (i.e., childhood obesity) through litter size reduction. Mice raised in small litters (SL) became obese as early as by two weeks of age, and as adults, they developed several obesity-related co-morbidities, including insulin resistance, glucose intolerance and hepatic steatosis. Here, we explored whether two independent short-term chrono-nutritional interventions might improve metabolic health in 1-month-old pre-pubertal SL mice. Both TRFs comprised 8 h feeding/14 h fasting. In the first one (TRF1) Control and SL mice had access to the diet for 8 h during the dark phase. In the second intervention (TRF2) food was available during the light:dark transitions.

RESULTS

TRF1 did not alter food intake nor ameliorate adiposity in SL-TRF1. In contrast, SL-TRF2 mice showed unintentional reduction of caloric intake, which was accompanied by reduced total body weight and adiposity. Strikingly, hepatic triglyceride content was completely normalized in SL-TRF1 and SL-TRF2 mice, when compared to the ad lib-fed SL mice. These effects were partially mediated by (i) clock-dependent signals, which might modulate the expression of Pparg or Cpt1a, and (ii) clock-independent signals, such as fasting itself, which could influence Fasn expression.

CONCLUSIONS

Time-restricted feeding is an effective and feasible nutritional intervention to improve metabolic health, namely hepatic steatosis, in a model of childhood obesity. These data open new avenues for future safe and efficient chrono-nutritional interventions aimed to improve metabolic health in children with overweight/obesity.

Energy Balance and Control of Body Weight: Possible Effects of Meal Timing and Circadian Rhythm Dysregulation

Conservation of the energy equilibrium can be considered a dynamic process and variations of one component (energy intake or energy expenditure) cause biological and/or behavioral compensatory changes in the other part of the system. The interplay between energy demand and caloric intake appears designed to guarantee an adequate food supply in variable life contexts. The circadian rhythm plays a major role in systemic homeostasis by acting as “timekeeper” of the human body, under the control of central and peripheral clocks that regulate many physiological functions such as sleep, hunger and body temperature. Clock-associated biological processes anticipate the daily demands imposed by the environment, being synchronized under ideal physiologic conditions. Factors that interfere with the expected demand, including daily distribution of macronutrients, physical activity and light exposure, may disrupt the physiologic harmony between predicted and actual behavior. Such a desynchronization may favor the development of a wide range of disease-related processes, including obesity and its comorbidities. Evidence has been provided that the main components of 24-h EE may be affected by disruption of the circadian rhythm. The sleep pattern, meal timing and meal composition could mediate these effects. An increased understanding of the crosstalk between disruption of the circadian rhythm and energy balance may shed light on the pathophysiologic mechanisms underlying weight gain, which may eventually lead to design effective strategies to fight the obesity pandemic.

Intermittent Fasting and the Possible Benefits in Obesity, Diabetes, and Multiple Sclerosis: A Systematic Review of Randomized Clinical Trials

Intermittent fasting has become popular in recent years and is controversially presented as a possible therapeutic adjunct. A bibliographic review of the literature on intermittent fasting and obesity, diabetes, and multiple sclerosis was carried out. The scientific quality of the methodology and the results obtained were evaluated in pairs. Intermittent fasting has beneficial effects on the lipid profile, and it is associated with weight loss and a modification of the distribution of abdominal fat in people with obesity and type 2 diabetes as well as an improvement in the control of glycemic levels. In patients with multiple sclerosis, the data available are too scarce to draw any firm conclusions, but it does appear that intermittent fasting may be a safe and feasible intervention. However, it is necessary to continue investigating its long-term effects since so far, the studies carried out are small and of short duration.

The effect of morning vs evening exercise training on glycaemic control and serum metabolites in overweight/obese men: a randomised trial

AIMS/HYPOTHESIS

We determined whether the time of day of exercise training (morning vs evening) would modulate the effects of consumption of a high-fat diet (HFD) on glycaemic control, whole-body health markers and serum metabolomics.

METHODS

In this three-armed parallel-group randomised trial undertaken at a university in Melbourne, Australia, overweight/obese men consumed an HFD (65% of energy from fat) for 11 consecutive days. Participants were recruited via social media and community advertisements. Eligibility criteria for participation were male sex, age 30-45 years, BMI 27.0-35.0 kg/m² and sedentary lifestyle. The main exclusion criteria were known CVD or type 2 diabetes, taking prescription medications, and shift-work. After 5 days, participants were allocated using a computer random generator to either exercise in the morning (06:30 hours), exercise in the evening (18:30 hours) or no exercise for the subsequent 5 days. Participants and researchers were not blinded to group assignment. Changes in serum metabolites, circulating lipids, cardiorespiratory fitness, BP, and glycaemic control (from continuous glucose monitoring) were compared between groups.

RESULTS

Twenty-five participants were randomised (morning exercise n = 9; evening exercise n = 8; no exercise n = 8) and 24 participants completed the study and were included in analyses (n = 8 per group). Five days of HFD induced marked perturbations in serum metabolites related to lipid and amino acid metabolism. Exercise training had a smaller impact than the HFD on changes in circulating metabolites, and only exercise undertaken in the evening was able to partly reverse some of the HFD-induced changes in metabolomic profiles. Twenty-four-hour glucose concentrations were lower after 5 days of HFD compared with the participants' habitual diet (5.3 ± 0.4 vs 5.6 ± 0.4 mmol/l, p = 0.001). There were no significant changes in 24 h glucose concentrations for either exercise group but lower nocturnal glucose levels were observed in participants who trained in the evening, compared with when they consumed the HFD alone (4.9 ± 0.4 vs 5.3 ± 0.3 mmol/l, p = 0.04). Compared with the no-exercise group, peak oxygen uptake improved after both morning (estimated effect 1.3 ml min^-1 kg^-1 [95% CI 0.5, 2.0], p = 0.003) and evening exercise (estimated effect 1.4 ml min^-1 kg^-1 [95% CI 0.6, 2.2], p = 0.001). Fasting blood glucose, insulin, cholesterol, triacylglycerol and LDL-cholesterol concentrations decreased only in participants allocated to evening exercise training. There were no unintended or adverse effects.

CONCLUSIONS/INTERPRETATION

A short-term HFD in overweight/obese men induced substantial alterations in lipid- and amino acid-related serum metabolites. Improvements in cardiorespiratory fitness were similar regardless of the time of day of exercise training. However, improvements in glycaemic control and partial reversal of HFD-induced changes in metabolic profiles were only observed when participants exercise trained in the evening.

TRIAL REGISTRATION

anzctr.org.au registration no. ACTRN12617000304336.

FUNDING

This study was funded by the Novo Nordisk Foundation (NNF14OC0011493).

Glycemic control by umbilical cord-derived mesenchymal stem cells promotes effects of fasting-mimicking diet on type 2 diabetic mice

BACKGROUND

Hepatic steatosis is a big hurdle to treat type 2 diabetes (T2D). Fasting-mimicking diet (FMD) has been shown to be an effective intervention in dyslipidemia of T2D. However, fasting may impair the normal glucose metabolism. Human umbilical cord-derived mesenchymal stem cell (UC-MSC) transplantation has been discovered to regulate immune reactions and reduce hyperglycemia in diabetes. However, the effect of UC-MSCs on improving the lipid metabolism disorder is not quite satisfactory. We have investigated the efficacy comparison and interaction between FMD and UC-MSC infusion, aiming to establish effective T2D therapies and explore its mechanism.

METHODS

C57/BL6 mice were fed with high-fat diet (HFD) to induce a diet-induced obese (DIO) mouse model. Leptin receptor-deficient (db/db) mice were used for follow-up experiments. DIO or db/db mice were divided into 4 groups: phosphate buffer saline (PBS), UC-MSCs, FMD, and UC-MSCs + FMD. At the end of the study period, mice were fasted and sacrificed, with the measurement of physiological and biochemical indexes. In addition, the fresh liver, skin, and white adipose tissue were analyzed by histology.

RESULTS

FMD restored the lipid metabolism in DIO mice, whereas its capacity to rescue hyperglycemia was uncertain. Infusion of UC-MSCs was effective in T2D glycemic control but the impact on dyslipidemia was insufficient. Furthermore, both the glucose and the lipid alterations of DIO and db/db mice recovered after UC-MSCs combined with FMD. It was proved that UC-MSCs promoted FMD effects on ameliorating hyperglycemia and restoring the lipid metabolism in T2D mice, while FMD had little promotion effect on UC-MSCs. Mechanistically, we discovered that UC-MSC infusion significantly modulated systematic inflammatory microenvironment, which contributed to concerted actions with FMD.

CONCLUSIONS

We established a strategy that combined UC-MSC infusion and FMD and was effective in treating T2D, which provided potential approaches for developing novel clinical T2D therapies.

Brain on food: The neuroepigenetics of nutrition

Humans have known for millennia that nutrition has a profound influence on health and disease, but it is only recently that we have begun mapping the mechanisms via which the dietary environment impacts brain physiology and behavior. Here we review recent evidence on the effects of energy-dense and methionine diets on neural epigenetic marks, gene expression, and behavior in invertebrate and vertebrate model organisms. We also discuss limitations, open questions, and future directions in the emerging field of the neuroepigenetics of nutrition.

Eating Habits and Sleep Quality during the COVID-19 Pandemic in Adult Population of Ecuador

Confinement due to COVID-19 has brought important changes in people’s lives as well as in their eating and resting habits. In this study we aimed at exploring the eating habits and sleep quality of the adult population of Ecuador during the mandatory confinement due to the COVID-19 pandemic. This is a cross-sectional study, which used an online survey that included questions about eating habits and sleeping habits in adults (n = 9522) between 18–69 years old. The Pittsburg sleep quality questionnaire validated for the Hispanic population was used, and questions about dietary habits. The statistical test Chi-square statistical test was used to analyze the data. The results show that sleep quality differs according to sex, being worse in women, both in all components of sleep quality and in the total score (p < 0.001). Women had greater changes in the habitual consumption of food compared to men (24.24% vs. 22.53%), and people between 18 and 40 years of age decreased their food consumption in relation to people >40 years (24.06% vs. 17.73%). Our results indicate that mandatory confinement due to the COVID-19 pandemic in Ecuador has generated changes in the eating habits and sleep quality in the adult population sampled, and these changes are more noticeable in women and young adults. These changes offer an important alert for the health system and further, advice for the implementation of future public health policies.

Chronological Age Interacts with the Circadian Melatonin Receptor 1B Gene Variation, Determining Fasting Glucose Concentrations in Mediterranean Populations. Additional Analyses on Type-2 Diabetes Risk

Gene-age interactions have not been systematically investigated on metabolic phenotypes and this modulation will be key for a better understanding of the temporal regulation in nutrigenomics. Taking into account that aging is typically associated with both impairment of the circadian system and a decrease in melatonin secretion, we focused on the melatonin receptor 1B (MTNR1B)-rs10830963 C>G variant that has been associated with fasting glucose concentrations, gestational diabetes, and type-2 diabetes. Therefore, our main aim was to investigate whether the association between the MTNR1B-rs10830963 polymorphism and fasting glucose is age dependent. Our secondary aims were to analyze the polymorphism association with type-2 diabetes and explore the gene-pregnancies interactions on the later type-2 diabetes risk. Three Mediterranean cohorts (n = 2823) were analyzed. First, a cross-sectional study in the discovery cohort consisting of 1378 participants (aged 18 to 80 years; mean age 41 years) from the general population was carried out. To validate and extend the results, two replication cohorts consisting of elderly individuals were studied. In the discovery cohort, we observed a strong gene-age interaction (p = 0.001), determining fasting glucose in such a way that the increasing effect of the risk G-allele was much greater in young (p = 5.9 × 10^-10) than in elderly participants (p = 0.805). Consistently, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose concentrations in the two replication cohorts (mean age over 65 years) did not reach statistical significance (p > 0.05 for both). However, in the elderly cohorts, significant associations between the polymorphism and type-2 diabetes at baseline were found. Moreover, in one of the cohorts, we obtained a statistically significant interaction between the MTNR1B polymorphism and the number of pregnancies, retrospectively assessed, on the type-2 diabetes risk. In conclusion, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose is age-dependent, having a greater effect in younger people. However, in elderly subjects, associations of the polymorphism with type-2 diabetes were observed and our exploratory analysis suggested a modulatory effect of the number of past pregnancies on the future type-2 diabetes genetic risk.

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.

Approaching Gravity as a Continuum Using the Rat Partial Weight-Bearing Model

For decades, scientists have relied on animals to understand the risks and consequences of space travel. Animals remain key to study the physiological alterations during spaceflight and provide crucial information about microgravity-induced changes. While spaceflights may appear common, they remain costly and, coupled with limited cargo areas, do not allow for large sample sizes onboard. In 1979, a model of hindlimb unloading (HU) was successfully created to mimic microgravity and has been used extensively since its creation. Four decades later, the first model of mouse partial weight-bearing (PWB) was developed, aiming at mimicking partial gravity environments. Return to the Lunar surface for astronauts is now imminent and prompted the need for an animal model closer to human physiology; hence in 2018, our laboratory created a new model of PWB for adult rats. In this review, we will focus on the rat model of PWB, from its conception to the current state of knowledge. Additionally, we will address how this new model, used in conjunction with HU, will help implement new paradigms allowing scientists to anticipate the physiological alterations and needs of astronauts. Finally, we will discuss the outstanding questions and future perspectives in space research and propose potential solutions using the rat PWB model.