Metabolic impacts of altering meal frequency and timing – Does when we eat matter?

Daily Brain Metabolic Rhythms of Wild Nocturnal Bats

Circadian rhythms are found in a wide range of organisms and have garnered significant research interest in the field of chronobiology. Under normal circadian function, metabolic regulation is temporally coordinated across tissues and behaviors within a 24 h period. Metabolites, as the closest molecular regulation to physiological phenotype, have dynamic patterns and their relationship with circadian regulation remains to be fully elucidated. In this study, untargeted brain metabolomics was employed to investigate the daily rhythms of metabolites at four time points corresponding to four typical physiological states in Vespertilio sinensis. Key brain metabolites and associated physiological processes active at different time points were detected, with 154 metabolites identified as rhythmic. Analyses of both metabolomics and transcriptomics revealed that several important physiological processes, including the pentose phosphate pathway and oxidative phosphorylation, play key roles in regulating rhythmic physiology, particularly in hunting and flying behaviors. This study represents the first exploration of daily metabolic dynamics in the bat brain, providing insights into the complex regulatory network of circadian rhythms in mammals at a metabolic level. These findings serve as a valuable reference for future studies on circadian rhythms in nocturnal mammals.

Maternal Obesity Induces the Meiotic Defects and Epigenetic Alterations During Fetal Oocyte Development

It has been widely reported that obesity adversely impacts reproductive performance of females. However, the effects of maternal obesity on fetal germ cells remain poorly understood. In the present study, by employing a high-fat diet (HFD)-based mouse model, it is discovered that maternal obesity disrupts the chromosomal synapsis and homologous recombination during fetal oogenesis. Moreover, transcriptomic profiling reveales the potential molecular network controlling this process. Of note, the global hypermethylation of genomic DNA in fetal oocytes from obese mouse is detected. Importantly, time-restricted feeding (TRF) of obese mice not only ameliorate the meiotic defects, but also partly restore the epigenetic remodeling in fetal oocytes. In sum, the evidence are provided showing the deficit fetal oogenesis in obese mother, implicating a mechanism underlying the intergenerational effects of environmental insults. TRF may represent a potentially effective approach for mitigating fertility issues in obese patients.

Meal Frequency Does Not Affect Weight Loss in Overweight/Obese Women but Affects the Body Composition: A Randomized Controlled Trial

OBJECTIVES

Studies showing the relationship between meal frequency, weight loss and anthropometric measurements are contradictory. This study aims to determine the effect of meal frequency on weight loss, anthropometric measurements, and body composition.

METHODS

This is a parallel designed randomized control trial that was conducted with 40 female volunteers between the ages of 19-64 years, with a Body Mass Index (BMI) ≥27 who applied to a private clinic. Participants were randomized in two treatment arms (3 meals + 3 snacks/day (n = 20) vs 3 meals/day (n = 20)) and same dietary energy restriction (-500kcal) was applied for 3 months. Food consumption was questioned with 3 day food records, and anthropometric measurements and body composition were measured before the study and repeated each week till the end of the study by the researcher.

RESULTS

All of the participants completed the study period. Body weight (kg), BMI (kg/m2), total body fat (kg), body fat percentage (%), fat free mass (kg) and waist circumference (cm) decreased, while fat free mass percentage (%) increased significantly in both of the groups at the end of the study (p < 0.05). The rate of difference for body weight, BMI (kg/m2) and waist circumference (cm) were similar among the groups. When difference in body composition analyses was examined, the rate of reduction in total body fat (-18.82 ± 4.97% vs -14.87 ± 7.44%) and body fat percentage (%)(-10.79 ± 4.63% vs -7.68 ± 7.04%) and the rate of increase in fat free mass percentage (%)(7.65 ± 3.16% vs 5.04 ± 3.44%) were significantly higher in 3 meals + 3 snacks group (p < 0.05).

CONCLUSION

When energy restricted and balanced weight loss programs are applied, alteration in body weight, BMI and waist circumference is not affected from meal frequency, but body composition does.

CLINICAL TRIAL NUMBER

NCT05581862 (Date of Trial Registration: 13/10/2022).

It's About Timing: Contrasting the Metabolic Effects of Early vs. Late Time-Restricted Eating in Humans

PURPOSE OF REVIEW

Time-restricted eating (TRE), a form of intermittent fasting, restricts feeding time across the day, imposing a daily 'eating window'. The time of day when the eating window occurs could result in differential metabolic effects. Here, we describe recent intervention studies in humans assessing the metabolic consequences of an early- (i.e., eating window starting in the early morning) vs. late (i.e., eating window starting after midday)-TRE protocol.

RECENT FINDINGS

Well-controlled studies indicate that both TRE protocols effectively reduce body weight and improve altered glucose metabolism, lipid profile, inflammation, or blood pressure levels. An early-TRE (e-TRE) might have a further positive impact on improving blood glucose, insulin levels, and insulin resistance. However, the studies directly assessing the metabolic consequences of an early- vs. late-TRE have shown dissimilar findings, and more well-controlled clinical trials are needed on the metabolic benefits of these two types of TRE. Evidence suggests that an e-TRE might have enhanced metabolic results, particularly regarding glucose homeostasis. More long-term studies, including larger sample sizes, are needed to assess the metabolic, circadian, and adherence benefits, together with socio-cultural acceptance of both TRE approaches.

Design and Rationale of Prolonged Nightly Fasting for Multiple Myeloma Prevention (PROFAST): Protocol for a Randomized Controlled Pilot Trial

BACKGROUND

Obesity is an established, modifiable risk factor of multiple myeloma (MM); yet, no lifestyle interventions are routinely recommended for patients with overweight or obesity with MM precursor conditions. Prolonged nightly fasting is a simple, practical dietary regimen supported by research, suggesting that the synchronization of feeding-fasting timing with sleep-wake cycles favorably affects metabolic pathways implicated in MM. We describe the design and rationale of a randomized controlled pilot trial evaluating the efficacy of a regular, prolonged nighttime fasting schedule among individuals with overweight or obesity at high risk for developing MM or a related lymphoid malignancy.

OBJECTIVE

We aim to investigate the effects of 4-month prolonged nightly fasting on body composition and tumor biomarkers among individuals with overweight or obesity with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), or smoldering Waldenström macroglobulinemia (SWM).

METHODS

Individuals with MGUS, SMM, or SWM aged ≥18 years and a BMI of ≥25 kg/m2 are randomized to either a 14-hour nighttime fasting intervention or a healthy lifestyle education control group. Participants' baseline diet and lifestyle patterns are characterized through two 24-hour dietary recalls: questionnaires querying demographic, comorbidity, lifestyle, and quality-of-life information; and wrist actigraphy measurements for 7 days. Fasting intervention participants are supported through one-on-one telephone counseling by a health coach and automated SMS text messaging to support fasting goals. Primary end points of body composition, including visceral and subcutaneous fat (by dual-energy x-ray absorptiometry); bone marrow adiposity (by bone marrow histology); and tumor biomarkers, specifically M-proteins and serum free light-chain concentrations (by gel-based and serum free light-chain assays), are assessed at baseline and after the 4-month study period; changes therein from baseline are evaluated using a repeated measures mixed-effects model that accounts for the correlation between baseline and follow-up measures and is generally robust to missing data. Feasibility is assessed as participant retention (percent dropout in each arm) and percentage of days participants achieved a ≥14-hour fast.

RESULTS

The PROlonged nightly FASTing (PROFAST) study was funded in June 2022. Participant recruitment commenced in April 2023. As of July 2023, six participants consented to the study. The study is expected to be completed by April 2024, and data analysis and results are expected to be published in the first quarter of 2025.

CONCLUSIONS

PROFAST serves as an important first step in exploring the premise that prolonged nightly fasting is a strategy to control obesity and obesity-related mechanisms of myelomagenesis. In evaluating the feasibility and impact of prolonged nightly fasting on body composition, bone marrow adipose tissue, and biomarkers of tumor burden, this pilot study may generate hypotheses regarding metabolic mechanisms underlying MM development and ultimately inform clinical and public health strategies for MM prevention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05565638; http://clinicaltrials.gov/ct2/show/NCT05565638.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51368.

Temporal patterns of energy intake identified by the latent class analysis in relation to prevalence of overweight and obesity in Iranian adults

We aimed to identify temporal patterns of energy intake and investigate their association with adiposity. We performed a cross-sectional study of 775 adults in Iran. Information about eating occasions across the day was collected by three 24-h dietary recalls. Latent class analysis (LCA) was used to identify temporal eating patterns based on whether or not an eating occasion occurred within each hour of the day. We applied binary logistic regression to estimate the OR and 95 % CI of overweight and obesity (defined as BMI of 25-29·9 and ≥ 30 kg/m2, respectively) across temporal eating patterns while controlling for potential confounders. LCA grouped participants into three exclusive sub-groups named 'Conventional', 'Earlier breakfast' and 'Later lunch'. The 'Conventional' class was characterised by high probability of eating occasions at conventional meal times. 'Earlier breakfast' class was characterised by high probability of a breakfast eating occasion 1 h before the conventional pattern and a dinner eating occasion 1 h after the conventional pattern, and the 'Later lunch' class was characterised by a high probability of a lunch eating occasion 1 h after the conventional pattern. Participants in the 'Earlier breakfast' pattern had a lower likelihood of obesity (adjusted OR: 0·56, 95 % CI: 0·35, 0·95) as compared with the 'Conventional' pattern. There was no difference in the prevalence of obesity or overweight between participants in the 'Later lunch' and the 'Conventional' patterns. We found an inverse association between earlier eating pattern and the likelihood of obesity, but reverse causation may be a plausible explanation.

The effects of eating frequency on changes in body composition and cardiometabolic health in adults: a systematic review with meta-analysis of randomized trials

BACKGROUND

Eating frequency may affect body weight and cardiometabolic health. Intervention trials and observational studies have both indicated that high- and low-frequency eating can be associated with better health outcomes. There are currently no guidelines to inform how to advise healthy adults about how frequently to consume food or beverages.

AIM

To establish whether restricted- (≤ three meals per day) frequency had a superior effect on markers of cardiometabolic health (primary outcome: weight change) compared to unrestricted-eating (≥ four meals per day) frequency in adults.

METHODS

We searched Medline (Ovid), Embase, CINAHL (EBSCO), Cochrane Central Register of Controlled Trials (CENTRAL), CAB Direct and Web of Science Core Collection electronic databases from inception to 7 June 2022 for clinical trials (randomised parallel or cross-over trials) reporting on the effect of high or low-frequency eating on cardiometabolic health (primary outcome: weight change). Trial interventions had to last for at least two weeks, and had to have been conducted in human adults. Bias was assessed using the Cochrane Risk of Bias tool 2.0. Standardized mean differences (SMD) and 95% confidence intervals were calculated for all outcomes. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Seventeen reports covering 16 trials were included in the systematic review. Data from five trials were excluded from meta-analysis due to insufficient reporting. 15 of 16 trials were at high risk of bias. There was very low certainty evidence of no difference between high- and low-frequency eating for weight-change (MD: -0.62 kg, CI95: -2.76 to 1.52 kg, p = 0.57).

CONCLUSIONS

There was no discernible advantage to eating in a high- or low-frequency dietary pattern for cardiometabolic health. We cannot advocate for either restricted- or unrestricted eating frequency to change markers of cardiometabolic health in healthy young to middle-aged adults.

PROTOCOL REGISTRATION

CRD42019137938.

Yerba Maté (Ilex paraguariensis) Supplement Exerts Beneficial, Tissue-Specific Effects on Mitochondrial Efficiency and Redox Status in Healthy Adult Mice

Yerba maté, a herbal tea derived from Ilex paraguariensis, has previously been reported to be protective against obesity-related and other cardiometabolic disorders. Using high-resolution respirometry and reverse-phase high-performance liquid chromatography, the effects of four weeks of yerba maté consumption on mitochondrial efficiency and cellular redox status in skeletal muscle, adipose, and liver, tissues highly relevant to whole-body metabolism, were explored in healthy adult mice. Yerba maté treatment increased the mitochondrial oxygen consumption in adipose but not in the other examined tissues. Yerba maté increased the ATP concentration in skeletal muscle and decreased the ATP concentration in adipose. Combined with the observed changes in oxygen consumption, these data yielded a significantly higher ATP:O2, a measure of mitochondrial efficiency, in muscle and a significantly lower ATP:O2 in adipose, which was consistent with yerba maté-induced weight loss. Yerba maté treatment also altered the hepatic glutathione (GSH)/glutathione disulfide (GSSG) redox potential to a more reduced redox state, suggesting the treatment's potential protective effects against oxidative stress and for the preservation of cellular function. Together, these data indicate the beneficial, tissue-specific effects of yerba maté supplementation on mitochondrial bioenergetics and redox states in healthy mice that are protective against obesity.

Association between Meal Frequency and Type 2 Diabetes Mellitus in Rural Adults: A Large-Scale Cross-Sectional Study

Diet frequency may potentially influence metabolic health. However, general population-based evidence on the association between meal frequency and type 2 diabetes mellitus (T2DM) remains limited and inconclusive. Thus, this study aimed to investigate the association between meal frequency and T2DM in resource limited area. A total of 29,405 qualified participants were enrolled from the Henan rural cohort study. Data on meal frequency were collected through a validated face-to-face questionnaire survey. Logistic regression models were utilized to explore the association between meal frequency and T2DM. Compared with 21 times per week meal frequency group, the adjusted odds ratios (ORs) and 95% confidence intervals (95%CIs) were 0.75 (0.58, 0.95) and 0.70 (0.54, 0.90) for 16–20 times/week group and 14–15 times/week group, respectively. For the analysis of the three meals, significant associations were only found between dinner frequency and T2DM. Compared with seven times per week dinner group, the ORs (95%CIs) were 0.66 (0.42, 0.99) and 0.51 (0.29, 0.82) for the group with three to six times/week and zero to two times/week. Reduced meal frequency, especially dinner frequency, was associated with lower prevalence of T2DM, which suggests that an appropriate reduction in meal frequency per week may have a role in decreasing the risk of T2DM.

When should I eat: A circadian view on food intake and metabolic regulation

The circadian clock is a hierarchical timing system regulating most physiological and behavioral functions with a period of approximately 24 h in humans and other mammalian species. The circadian clock drives daily eating rhythms that, in turn, reinforce the circadian clock network itself to anticipate and orchestrate metabolic responses to food intake. Eating is tightly interconnected with the circadian clock and recent evidence shows that the timing of meals is crucial for the control of appetite and metabolic regulation. Obesity results from combined long-term dysregulation in food intake (homeostatic and hedonic circuits), energy expenditure, and energy storage. Increasing evidence supports that the loss of synchrony of daily rhythms significantly impairs metabolic homeostasis and is associated with obesity. This review presents an overview of mechanisms regulating food intake (homeostatic/hedonic) and focuses on the crucial role of the circadian clock on the metabolic response to eating, thus providing a fundamental research axis to maintain a healthy eating behavior.

The Discovery of Data-Driven Temporal Dietary Patterns and a Validation of Their Description Using Energy and Time Cut-Offs

Data-driven temporal dietary patterning (TDP) methods were previously developed. The objectives were to create data-driven temporal dietary patterns and assess concurrent validity of energy and time cut-offs describing the data-driven TDPs by determining their relationships to BMI and waist circumference (WC). The first day 24-h dietary recall timing and amounts of energy for 17,915 U.S. adults of the National Health and Nutrition Examination Survey 2007−2016 were used to create clusters representing four TDPs using dynamic time warping and the kernel k-means clustering algorithm. Energy and time cut-offs were extracted from visualization of the data-derived TDPs and then applied to the data to find cut-off-derived TDPs. The strength of TDP relationships with BMI and WC were assessed using adjusted multivariate regression and compared. Both methods showed a cluster, representing a TDP with proportionally equivalent average energy consumed during three eating events/day, associated with significantly lower BMI and WC compared to the other three clusters that had one energy intake peak/day at 13:00, 18:00, and 19:00 (all p < 0.0001). Participant clusters of the methods were highly overlapped (>83%) and showed similar relationships with obesity. Data-driven TDP was validated using descriptive cut-offs and hold promise for obesity interventions and translation to dietary guidance.

The Effect of Personality on Chrononutrition during the COVID-19 Lockdown in Qatar

The COVID-19 lockdown has had a significant impact on people's lives worldwide. This study aimed to investigate the effect of personality on chrononutrition during the COVID-19 lockdown. Using a cross-sectional design, a convenient sample of 543 adults in Qatar completed an online questionnaire using validated tools to assess personality and chrononutrition behaviors during the first COVID-19 lockdown. Participants scoring high in openness were more likely to eat at night (mean difference (MD) = 0.41, 95% confidence interval (CI): 0.10, 0.72) compared to those scoring high in agreeableness, while those scoring high in extraversion and openness had a shorter eating window (MD = -76.6, 95%CI: -146.3, -6.93 and MD = -29.8, 95%CI: -56.5, -3.01, respectively). Participants high in extraversion had longer evening latency (MD = 66.3, 95%CI: 25.4, 107.3) and evening eating (MD = -62.0, 95%CI: -114.0, -9.0) compared those high in agreeableness. Participants high in conscientiousness showed evidence of first eating event misalignment during the weekend (MD = 22.0, 95%CI: 0.15, 43.9) and last eating event misalignment during weekdays (MD = -27.8, 95%CI: -47.3, -8.41) compared to those high in agreeableness. Lastly, participants high in openness showed evidence of eating window misalignment during the weekend (MD = 30.6, 95%CI: 5.01, 56.2). This study suggests that personality traits can inform personalized nutritional approaches when aiming for healthy habits during unexpected periods, such as the COVID-19 pandemic.

Joint association of meal frequency and diet quality with metabolic syndrome in Iranian adults

BACKGROUND

Metabolic syndrome (MetS) is a common complication that has been shown in various studies to be related to the frequency and timing of eating. We aimed to evaluate the relationship between meal timing and frequency with diet quality and prevalence of MetS.

STUDY DESIGN

Cross-sectional.

METHODS

We analyzed data from 850 adults (20 to 59 years) and divided the participants into different categories in terms of frequency of eating occasions (EO) (5 ≥ , 6-7 and 7 <), meal (2 ≥ and 3) and snack (2 ≥ , 3 and 4 ≤) in a day. Daily food consumption was assessed using the structured three 24-h recalls. The quality of diet we calculated using the food quality score (FQS). Metabolic syndrome was defined based on the guidelines of the national cholesterol education program adult treatment panel III (ATP III). The covariates-adjusted relationships between exposures and outcomes were investigated using a logistic regression test and two-way ANOVA.

RESULTS

The overall prevalence of MetS in participants was 34.2%. The average FQS was 28.0. Increased frequency of EOs and snacks was related to the higher prevalence of MetS ((OR, 1.72; 95% CI, 1.24, 2.37; P < 0.01) and (OR, 1.34; 95% CI, 1.07, 1.68; P, 0.01), respectively). The adjusted mean of FQS was not significantly different between the EO as well as meals and snack categories. The joint association of EO frequency and snack frequency with diet quality showed a higher chance of having MetS ( (OR, 2.36; 95% CI, 1.19, 4.66; P, 0.01 and (OR, 1.68; 95% CI, 1.06, 2.68; P,0.02), respectively). Also, we observed a higher mean of high density level cholesterol in people with the highest FQS and lowest EO frequency (P,0.02).

CONCLUSION

Our findings suggest that the EO and snack frequency may be associated with the higher chance of MetS. We also found when the frequency of EO increases, the beneficial associations of the diet quality were overshadowed. To confirm our findings, well designed randomised clinical trials are needed.

A Time to Rest, a Time to Dine: Sleep, Time-Restricted Eating, and Cardiometabolic Health

Cardiovascular disease (CVD) poses a serious health and economic burden worldwide. Modifiable lifestyle factors are a focus of research into reducing the burden of CVD, with diet as one of the most investigated factors. Specifically, the timing and regularity of food intake is an emerging research area, with approaches such as time-restricted eating (TRE) receiving much attention. TRE involves shortening the time available to eat across the day and is associated with improved CVD outcomes compared with longer eating windows. However, studies that have examined TRE have not considered the impact of sleep on CVD outcomes despite recent evidence showing that sleep duration can influence the timing and amount of food eaten. In this article, we argue that as TRE and sleep influence each other, and influence the same cardiometabolic parameters, experiencing inadequate sleep may attenuate any positive impact TRE has on CVD. We examine the relationship between TRE and CVD, with sleep as a potential mediator in this relationship, and propose a research agenda to investigate this relationship. This will provide necessary evidence to inform future interventions aimed at reducing the burden of CVD.

Face Validity of Observed Meal Patterns Reported with 7-Day Diet Diaries in a Large Population-Based Cohort Using Diurnal Variation in Concentration Biomarkers of Dietary Intake

In a cross-sectional analysis of a population-based cohort (United Kingdom, N = 21,318, 1993-1998), we studied how associations between meal patterns and non-fasting triglyceride and glucose concentrations were influenced by the hour of day at which the blood sample was collected to ascertain face validity of reported meal patterns, as well as the influence of reporting bias (assessed using formula of energy expenditure) on this association. Meal size (i.e., reported energy content), mealtime and meal frequency were reported using pre-structured 7-day diet diaries. In ANCOVA, sex-specific means of biomarker concentrations were calculated by hour of blood sample collection for quartiles of reported energy intake at breakfast, lunch and dinner (meal size). Significant interactions were observed between breakfast size, sampling time and triglyceride concentrations and between lunch size, sampling time and triglyceride, as well as glucose concentrations. Those skipping breakfast had the lowest triglyceride concentrations in the morning and those skipping lunch had the lowest triglyceride and glucose concentrations in the afternoon, especially among acceptable energy reporters. Eating and drinking occasion frequency was weakly associated with glucose concentrations in women and positively associated with triglyceride concentrations in both sexes; stronger associations were observed for larger vs. smaller meals and among acceptable energy reporters. Associations between meal patterns and concentration biomarkers can be observed when accounting for diurnal variation and underreporting. These findings support the use of 7-day diet diaries for studying associations between meal patterns and health.

Plant-Based Diet and IGF-1 Modulation on HER2-Positive Breast Cancer: A Lifestyle Medicine Nutrition Approach in Oncology

Breast cancer is the second most common type of cancer in women worldwide, where nutritional intervention should be part of a multidisciplinary lifestyle approach in oncology, promoting therapeutic success. Insulin-like growth factor 1 (IGF-1), along with estrogen, can promote the development of neoplastic cells in breast tissue. Cancers that develop under IGF-1 stimulation are often resistant to therapy. This case report describes a 47-year-old woman, body mass index 27.4 kg/m2, with HER2-positive breast cancer, as well as elevated blood glucose, total cholesterol, and low-density lipoprotein cholesterol. Soon after her breast cancer diagnosis, she transitioned from a Western pattern diet (WPD) to a predominantly whole-food, plant-based diet (PWFPBD) for 1035 days, followed by 232 days of PWFPBD plus night fasting for 16 hours per day. IGF-1 decreased 22.38%, glycemia and total cholesterol decreased by -55.06% and -36.00% at the end of the first intervention and went up by 6.25%, and 3.87%, respectively, at the end of the second intervention. A PWFPBD, with or without 16-hour overnight fasting, seems to modulate plasma levels of IGF-1 on a 47-year-old woman diagnosed with breast cancer, type HER2-positive. Future research, should explore the physiologic and pathophysiological mechanisms and clarify whether this dietary strategy, may be clinically useful in preventing HER2-positive breast cancer.

Hypocaloric diet with lower meal frequency did not affect weight loss, body composition and insulin responsiveness, but improved lipid profile: a randomized clinical trial

Dietary approaches are essential to control obesity, but the effectiveness of changes in meal frequency (MF) as a strategy for body weight loss or maintenance remain unclear. This study aimed to evaluate the influence of MF of a hypocaloric diet on weight loss, body composition, active ghrelin levels and metabolic indicators of obese women. This is a randomized, parallel clinical trial, including 40 women divided into two groups that received a hypocaloric diet with different MFs: MF6: six meals per day, and MF3: three meals per day. Dietary, laboratory, anthropometric and body composition indicators were assessed, as well as energy expenditure (EE), before and after the 90 days of the intervention. Dietary consumption did not differ between groups, before or after intervention. The two groups reduced their energy intake after intervention, but there were no differences between the groups. Waist circumference (WC) was reduced and resting metabolic rate had increased in the MF3 group at the end compared to baseline. Moreover, there was a significant difference in the triglyceride levels between groups after intervention, with an important reduction in the MF3 group, although changes in body composition, blood glucose, plasma ghrelin levels and EE variables did not differ between the groups at the end. It is concluded that, the hypocaloric diet with different MF each day did not change weight loss, body composition or insulin responsiveness, but there was an improvement of triglyceridemia in the MF3 group. The present study suggests that eating snacks between meals is not an important factor for weight loss and improvement of metabolic health in women with obesity.

Association between daily number of eating occasions with fasting glucose and insulin sensitivity in adults from families at high risk for type 2 diabetes in Europe: the Feel4Diabetes Study

OBJECTIVE

The aim of this study was to examine the association between the number of times one eats daily (termed eating occasions [EO]) with indices of glycemic control and insulin resistance (IR) in a large sample of adults from families at high risk for type 2 diabetes mellitus (T2DM) from six European countries. The study also considered sex and socioeconomic status (SES).

METHODS

Standardized questionnaires and procedures were used to assess sociodemographic characteristics, dietary intake, sedentary behavior, and anthropometric and biochemical indices. Univariate analysis of variance was used to investigate associations of daily EOs with fasting glucose (FG), fasting insulin (FI), and IR.

RESULTS

In 1552 adults (41.6 ± 7.2 y), three to four daily EOs rather than less than three were inversely associated with FG (β = -2.598; 95% confidence interval [CI], -4.521 to -0.675), independent of age, body mass index (BMI), dietary quality, and sedentary time. In women, three to four EOs per day were also associated with FG (β = -3.071; 95% CI to -5.573 to -0.570) independently of the mentioned confounders. In high SES participants, having more than four EOs per day had an inverse association with FI (β = -1.348; 95% CI to -2.583 to -0.114). No such associations were observed in men or in low SES participants.

CONCLUSION

In adults at high risk for T2DM, and especially in women, having three to four daily EOs was inversely associated with FG, whereas in high SES participants, more than four EOs was associated with FI. Future studies should further elucidate the underlying mechanisms and offer insight into the optimum number of daily EOs for the prevention of T2DM especially in men and in adults with low SES where the number of daily EOs was not found to be significantly related to glycemic indices.

Effects of intermittent fasting on liver physiology and metabolism in mice

A broad spectrum of health benefits from intermittent fasting have been reported in studies on animal models and human subjects. However, the underlying mechanisms of these beneficial effects remain largely elusive. The present study aimed to explore the effects and potential mode of action of intermittent fasting in mouse models with a focus on the liver. C57BL/6 mice were subjected to intermittent fasting or ad libitum feeding as controls. It was determined that 12 h of daily intermittent fasting for 30 days significantly reduced the cumulative food intake compared with that in mice with ad libitum feeding. Fasting resulted in a significantly reduced liver mass but only had a minimal effect on bodyweight. The effects on the liver by 30 days of fasting were not reversed by subsequent ad libitum refeeding for 30 days. Among the measured blood biochemical parameters, the levels of blood glucose were decreased, while the levels of alkaline phosphatase were increased in fasting mice. Of note, targeted metabolic profiling revealed global elevation of metabolites in the livers of fasting mice. These metabolic molecules included adenosine triphosphate, nicotinamide adenine dinucleotide phosphate (NADP), reduced NADP and succinate, which are essentially involved in the citric acid cycle and oxidative phosphorylation. Thus, it was concluded that daily 12 h of intermittent fasting for one month significantly reduced the liver weight of mice, which is associated with enhanced liver metabolism.

Assessing Time of Eating in Commensality Research

Commensal meals seem to be related to a better nutritional and metabolic health as well as an improved quality of life. The aim of this paper was to examine to what extent research was performed using the search term commensality related to assessment of timing of meals. A scoping review was performed, where 10 papers were identified as specifically addressing the assessment of timing of commensality of meals. Time use studies, questionnaires, and telephone- and person-to-person interviews were used for assessing meal times in relation to commensality. Four of the studies used a method of time use registration, and six papers used interviews or questionnaires. Common meals with family members were the most common, and dinners late at night were often preferred for commensal activities among the working population. In conclusion, the family meal seemed to be the most important commensal meal. It is clear from the collected papers and from previous systematic reviews that more studies of commensal meals in general and about timing aspects in particular and in relation to nutritional health are essential to provide a solid background of knowledge regarding the importance of timing in relation to commensal meals.

Circadian depression: A mood disorder phenotype

Major mood syndromes are among the most common and disabling mental disorders. However, a lack of clear delineation of their underlying pathophysiological mechanisms is a major barrier to prevention and optimised treatments. Dysfunction of the 24-h circadian system is a candidate mechanism that has genetic, behavioural, and neurobiological links to mood syndromes. Here, we outline evidence for a new clinical phenotype, which we have called 'circadian depression'. We propose that key clinical characteristics of circadian depression include disrupted 24-h sleep-wake cycles, reduced motor activity, low subjective energy, and weight gain. The illness course includes early age-of-onset, phenomena suggestive of bipolarity (defined by bidirectional associations between objective motor and subjective energy/mood states), poor response to conventional antidepressant medications, and concurrent cardiometabolic and inflammatory disturbances. Identifying this phenotype could be clinically valuable, as circadian-targeted strategies show promise for reducing depressive symptoms and stabilising illness course. Further investigation of underlying circadian disturbances in mood syndromes is needed to evaluate the clinical utility of this phenotype and guide the optimal use of circadian-targeted interventions.

Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse models

Accumulating evidence indicates that obesity with its associated metabolic dysregulation, including hyperinsulinemia and aberrant circadian rhythms, increases the risk for a variety of cancers including postmenopausal breast cancer. Caloric restriction can ameliorate the harmful metabolic effects of obesity and inhibit cancer progression but is difficult to implement and maintain outside of the clinic. In this study, we aim to test a time-restricted feeding (TRF) approach on mouse models of obesity-driven postmenopausal breast cancer. We show that TRF abrogates the obesity-enhanced mammary tumor growth in two orthotopic models in the absence of calorie restriction or weight loss. TRF also reduces breast cancer metastasis to the lung. Furthermore, TRF delays tumor initiation in a transgenic model of mammary tumorigenesis prior to the onset of obesity. Notably, TRF increases whole-body insulin sensitivity, reduces hyperinsulinemia, restores diurnal gene expression rhythms in the tumor, and attenuates tumor growth and insulin signaling. Importantly, inhibition of insulin secretion with diazoxide mimics TRF whereas artificial elevation of insulin through insulin pumps implantation reverses the effect of TRF, suggesting that TRF acts through modulating hyperinsulinemia. Our data suggest that TRF is likely to be effective in breast cancer prevention and therapy.

Eating Timing: Associations with Dietary Intake and Metabolic Health

BACKGROUND

Emerging research indicates that eating timing may influence dietary intake and metabolic health. However, studies to date have not examined the association of multiple measures of eating timing with both dietary intake and metabolic health in adults with overweight and obesity.

OBJECTIVE

To examine the association of multiple measures of eating timing with dietary intake (ie, dietary composition, diet quality, and eating frequency) and metabolic health (ie, body composition and cardiometabolic risk).

DESIGN

This is a cross-sectional analysis of baseline data from a weight loss and maintenance intervention collected from May 2015 to January 2018.

PARTICIPANTS/SETTING

Participants were women with overweight or obesity who were dependents of active duty and retired military personnel (N = 229; mean ± standard error, BMI = 34.7 ± 0.4 kg/m², age = 40.9 ± 0.7 years). The study was conducted at military installations in Massachusetts, Connecticut, New York, Colorado, and Kentucky.

MAIN OUTCOME MEASURES

Eating timing variables examined included daily eating interval (time between first and last eating occasion), time-restricted eating (≤11 hours daily eating interval), early energy eaters (eating ≥60% of energy during the first half of time awake), and bedtime eaters (eating within 2 hours of bedtime).

STATISTICAL ANALYSIS

The main analysis was limited to those reporting plausible energy intake (64% of total sample [n = 146]). Linear, quantile, or logistic regression models were used to determine the association of eating timing with measures of dietary intake and metabolic health.

RESULTS

In individuals reporting plausible energy intake, each additional 1 hour in daily eating interval was associated with 53 kcal higher energy intake, higher glycemic load, eating frequency, and waist circumference (P < 0.05 for all). Significant associations were observed for: time-restricted eating and a lower energy intake, glycemic load, and eating frequency; early energy eating and higher carbohydrate intake; bedtime eating and a higher energy intake, glycemic load, and eating frequency.

CONCLUSIONS

These findings lend support for the mechanistic targeting of eating timing in behavioral interventions aimed at improving dietary intake and body composition.

Dietary Protein Intake Patterns and Inadequate Protein Intake in Older Adults from Four Countries

Recent interest in protein intake per meal is observed in studies that have reported the protein intake patterns in different countries; however, comparisons of these data are lacking. We aimed to compare protein intake patterns and the percentage of inadequate protein intake (IPI) per day and meal in older adults from different countries. We acquired data of protein intake in older adults from four countries (Mexico, United States of America, Germany, and United Kingdom). We compared protein intake (per day and meal), IPI per day and meal, and the number of meals with an adequate protein content among countries. The IPI per day significantly differed among countries for <0.8 and <1.0 (both p < 0.001), but not for <1.2 g/kg/d (p = 0.135). IPI per meal (<30 g/meal) did not differ among countries at breakfast (p = 0.287) and lunch (p = 0.076) but did differ at dinner (p < 0.001). Conversely, IPI per meal (<0.4 g/kg/meal) significantly differed among countries at breakfast, lunch, and dinner (all p < 0.001). The percentage of participants that ate ≥30 g/meal or ≥0.4 g/kg/meal at zero, one, and two or three meals per day significantly differed among countries (all p < 0.05). IPI at breakfast and lunch (<30 g/meal) was a common trait in the analyzed samples and might represent an opportunity for nutritional interventions in older adults in different countries.

The effects of COVID-19 quarantine on eating and sleeping behaviors

Abstract

Since the beginning of the pandemic, the population has been exposed to a substantial period of social isolation, which leads to anxiety, fear, and metabolic and immune impairments.

Purpose

Considering that sleep restriction influences eating behavior, we highlight that changes in it may occur during the COVID-19 quarantine. Alterations in feeding time can uncouple the body clocks, leading to circadian misalignment and consequently to a disruption in homeostasis and disturbances in many metabolic functions.

Method

Narrative review.

Results

Do not apply.

Conclusion

The increase of body weight is related to increased food intake in response to mental stress and more time spent at home, increased opportunity to feed, and increased visual and olfactory stimulation to eat, which represents a potential risk of overfeeding nowadays. In this article, we postulate that the unusual lifestyle imposed by the COVID-19 quarantine may induce a circadian misalignment, which is capable to induce alterations on eating and sleep behaviors.

Ramadan Intermittent Fasting Affects Adipokines and Leptin/Adiponectin Ratio in Type 2 Diabetes Mellitus and Their First-Degree Relatives

Background

In view of the association of Ramadan intermittent fasting with profound changes in lifestyle both in nondiabetic and diabetic patients, the aim of this study was to investigate the effect of Ramadan fasting on adiponectin, leptin and leptin to adiponectin ratio (LAR), growth hormone (GH), human-sensitive C-reactive protein (hs-CRP), and diabetic and metabolic syndrome factors in patients with Type 2 Diabetes Mellitus (Type 2 DM), their first-degree relatives (FDRs), and healthy controls.

Methods

This cohort study involved 98 Yemeni male subjects aged 30-70 years old: 30 Type 2 DM, 37 FDRs of Type 2 diabetic patients, and 31 healthy control subjects. Subjects' body mass index (BMI), waist circumference (WC), and blood pressure (BP) were measured, and venous blood samples were collected twice: the first samples were collected a couple of days prior to Ramadan fasting (baseline) and the second samples after 3 weeks of fasting.

Results

Ramadan fasting did not affect BMI, WC, and BP in Type 2 DM and their FDRs with respect to the baseline levels prior to Ramadan, whereas triglyceride and cholesterol were borderline significantly decreased in Type 2 DM with no effect in FDRs. Fasting blood glucose was not affected in Type 2 DM but was significantly increased in FDRs and control groups, whereas glycated haemoglobin (HbA1c) was slightly decreased in Type 2 DM, FDRs, and healthy controls. C-peptide, insulin, and insulin resistance (HOMA-IR) were significantly increased in Type 2 DM and FDRs, with no effect in the control group, whereas β-cell function (HOMA-β) was significantly decreased in FDRs and controls with no change in Type 2 DM. Ramadan fasting significantly decreased GH in both FDRs and control groups, and significantly increased hs-CRP in the control with no effect in Type 2 DM and FDRs. Adiponectin was significantly decreased, and leptin and LAR were significantly increased in Type 2 DM, FDRs, and control groups.

Conclusion

Ramadan intermittent fasting decreased adiponectin and increased leptin, LAR, insulin, and insulin resistance in both Type 2 DM and FDRs as well as decreased GH in both FDRs and healthy controls and increased hs-CRP in healthy controls. Moreover, Ramadan intermittent fasting neither worsens a patient's glycemic parameters nor improves it, with the exception of a slight improvement in HbA1c in Type 2 DM, FDRs, and healthy controls.

Energy, Nutrient and Food Intakes of Male Shift Workers Vary According to the Schedule Type but Not the Number of Nights Worked

Shift work is associated with increased risk of chronic diseases due to circadian rhythm disruptions and behavioral changes such as in eating habits. Impact of type of shifts and number of night shifts on energy, nutrient and food intake is as yet unknown. Our goal was to analyze shift workers’ dietary intake, eating behavior and eating structure, with respect to frequency of nights worked in a given week and seven schedule types. Eating habits and dietary intakes of 65 male shift workers were analyzed in three steps based on 365 24-h food records: (1) according to the number of nights, (2) in a pooled analysis according to schedule type, and (3) in search of an interaction of the schedule and the timing of intake. Mean nutrient and food group intake during the study period did not depend on the number of nights worked. Amount and distribution of energy intake as well as quality of food, in terms of nutrient and food groups, differed depending on the type of schedule, split night shifts and recovery day (day after night shift) being the most impacted. Shift workers’ qualitative and quantitative dietary intakes varied between different schedules, indicating the need for tailored preventive interventions.

Effects of time-restricted feeding on body weight and metabolism. A systematic review and meta-analysis

Restriction in meal timing has emerged as a promising dietary approach for the management of obesity and dysmetabolic diseases. The present systematic review and meta-analysis summarized the most recent evidence on the effect of time-restricted feeding (TRF) on weight-loss and cardiometabolic variables in comparison with unrestricted-time regimens. Studies involving TRF regimen were systematically searched up to January 2019. Effect size was expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). A total of 11 studies, 5 randomized controlled trials and 6 observational, were included. All selected studies had a control group without time restriction; hours of fasting ranged from 12-h until 20-h and study duration from 4 to 8-weeks. Most studies involved the Ramadan fasting. TRF determined a greater weight-loss than control regimens (11 studies, n = 485 subjects) (WMD: -1.07 kg, 95%CI: -1.74 to -0.40; p = 0.002; I² = 56.2%), unrelated to study design. The subgroup analysis showed an inverse association between TRF and fat free mass in observational studies (WMD: -1.33 kg, 95%CI: -2.55 to -0.11; p = 0.03; I² = 0%). An overall significant reduction in fasting glucose concentrations was observed with TRF regimens (7 studies, n = 363 subjects) (WMD: -1.71 mg/dL, 95%CI: -3.20 to -0.21; p = 0.03; I² = 0%), above all in trials (WMD:-2.45 mg/dL, 95%CI: -4.72 to -0.17; p = 0.03; I² = 0%). No between-group differences in the other variables were found. TRF regimens achieved a superior effect in promoting weight-loss and reducing fasting glucose compared to approaches with unrestricted time in meal consumption. However, long-term and well-designed trials are needed to draw definitive conclusions.

Nutritional Recommendations for Physique Athletes

The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and female physique athletes in the contest preparation and recovery period. As optimal protein intake is largely related to one’s skeletal muscle mass, current evidence supports a range of 1.8-2.7 g/kg. Furthermore, as a benefit from having adequate carbohydrate to fuel performance and activity, low-end fat intake during contest preparation of 10-25% of calories allows for what calories remain in the “energy budget” to come from carbohydrate to mitigate the negative impact of energy restriction and weight loss on training performance. For nutrient timing, we recommend consuming four or five protein boluses per day with one consumed near training and one prior to sleep. During competition periods, slower rates of weight loss (≤0.5% of body mass per week) are preferable for attenuating the loss of fat-free mass with the use of intermittent energy restriction strategies, such as diet breaks and refeeds, being possibly beneficial. Additionally, physiological and psychological factors are covered, and potential best-practice guidelines are provided for disordered eating and body image concerns since physique athletes present with higher incidences of these issues, which may be potentially exacerbated by certain traditional physique practices. We also review common peaking practices, and the critical transition to the post-competition period.

Reduction in Glycated Hemoglobin and Daily Insulin Dose Alongside Circadian Clock Upregulation in Patients With Type 2 Diabetes Consuming a Three-Meal Diet: A Randomized Clinical Trial

OBJECTIVE

In type 2 diabetes, insulin resistance and progressive β-cell failure require treatment with high insulin doses, leading to weight gain. Our aim was to study whether a three-meal diet (3Mdiet) with a carbohydrate-rich breakfast may upregulate clock gene expression and, as a result, allow dose reduction of insulin, leading to weight loss and better glycemic control compared with an isocaloric six-meal diet (6Mdiet).

RESEARCH DESIGN AND METHODS

Twenty-eight volunteers with diabetes (BMI 32.4 ± 5.2 kg/m² and HbA_1c 8.1 ± 1.1% [64.5 ± 11.9 mmol/mol]) were randomly assigned to 3Mdiet or 6Mdiet. Body weight, glycemic control, continuous glucose monitoring (CGM), appetite, and clock gene expression were assessed at baseline, after 2 weeks, and after 12 weeks.

RESULTS

3Mdiet, but not 6Mdiet, led to a significant weight loss (-5.4 ± 0.9 kg) (P < 0.01) and decreased HbA_1c (-12 mmol/mol [-1.2%]) (P < 0.0001) after 12 weeks. Fasting glucose and daily and nocturnal glucose levels were significantly lower on the 3Mdiet. CGM showed a significant decrease in the time spent in hyperglycemia only on the 3Mdiet. Total daily insulin dose was significantly reduced by 26 ± 7 units only on the 3Mdiet. There was a significant decrease in the hunger and cravings only in the 3Mdiet group. Clock genes exhibited oscillation, increased expression, and higher amplitude on the 3Mdiet compared with the 6Mdiet.

CONCLUSIONS

A 3Mdiet, in contrast to an isocaloric 6Mdiet, leads to weight loss and significant reduction in HbA_1c, appetite, and overall glycemia, with a decrease in daily insulin. Upregulation of clock genes seen in this diet intervention could contribute to the improved glucose metabolism.

Differential Effects of Alternate-Day Fasting Versus Daily Calorie Restriction on Insulin Resistance

OBJECTIVE

This study compared the effects of alternate-day fasting (ADF) with those of daily calorie restriction (CR) on body weight and glucoregulatory factors in adults with overweight or obesity and insulin resistance.

METHODS

This secondary analysis examined the data of insulin-resistant individuals (n = 43) who participated in a 12-month study that compared ADF (25% energy needs on "fast days"; 125% energy needs on alternating "feast days") with CR (75% energy needs every day) and a control group regimen.

RESULTS

In insulin-resistant participants, weight loss was not different between ADF (-8% ± 2%) and CR (-6% ± 1%) by month 12, relative to controls (P < 0.0001). Fat mass and BMI decreased (P < 0.05) similarly from ADF and CR. ADF produced greater decreases (P < 0.05) in fasting insulin (-52% ± 9%) and insulin resistance (-53% ± 9%) compared with CR (-14% ± 9%; -17% ± 11%) and the control regimen by month 12. Lean mass, visceral fat mass, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, blood pressure, C-reactive protein, tumor necrosis factor α, and interleukin 6 values remained unchanged.

CONCLUSIONS

These findings suggest that ADF may produce greater reductions in fasting insulin and insulin resistance compared with CR in insulin-resistant participants despite similar decreases in body weight.

Chrono-Nutrition: The Relationship between Time-of-Day Energy and Macronutrient Intake and Children’s Body Weight Status

The time of eating has been considered to have an important role in weight regulation. However, it is unknown if there are specific daily patterns of energy and macronutrient distribution that could be more beneficial for metabolic outcomes, especially obesity. This study aimed to assess the effect of time-of-day energy and macronutrient intake at 4 y of age on the weight status at 7 y of age. The study sample included 1961 children from the population-based birth cohort Generation XXI, with data on 3-day food diaries at 4 y and body mass index (BMI) z-scores at 7 y. Dietary patterns based on the collected data were obtained for the distribution of energy and macronutrients across eating occasions. Having a relatively higher energy intake at lunch and supper (OR = 1.19, 95% CI = 1.05 to 1.34) or at mid-afternoon (OR = 1.18, 95% CI = 1.05 to 1.34) at 4 y was associated with higher odds of becoming overweight/obese at 7 y. A relatively higher intake of fat at lunch was positively associated with later children’s odds for being overweight or obese (OR = 1.17, 95% CI = 1.03 to 1.32). These associations were independent of the effect on children’s eating behaviors related to appetite. Our results also show a detrimental relation between skipping breakfast and eating late in the day and children’s body weight. Considering all daily eating occasions, a higher proportion of energy and macronutrient intake at the main meals and a lower proportion during the afternoon and evening seems to be more beneficial for children’s weight. These results emphasize the important role of daily food intake rhythm on excessive weight gain in childhood.

Eating behaviours and dietary intake associations with self-reported sleep duration of free-living Brazilian adults

Sleep duration in modern societies has been decreasing over the past decades and many environmental and behaviour factors contribute with. Evidence have shown that individuals with short sleep duration have worse eating behaviours and dietary intakes than those with adequate sleep. This study aimed to describe eating behaviours and dietary intakes of Brazilian adults and investigate their associations with self-reported sleep duration encompassing aspects of chrono-nutrition. Demographic, socioeconomic, anthropometric, lifestyle, sleep duration and dietary data were obtained from an interviewer-administered structured questionnaire of the cross-sectional population-based study, 2015 ISA-Capital, (n = 1081 adults, ≥20y). The independent associations between sleep duration (categories: ≤6 h, 7-8 h, and ≥9 h) and dietary variables were assessed after adjustment for covariates. Employment status, physical activity, number of chronic diseases and day of recalled intake were significantly associated with sleep duration categories (p < 0.05). Short duration sleepers (≤6 h) showed the largest probabilities of eating breakfast and snacks. Snacks contributed to 23% of total energy intake and provided the largest amounts of total and added sugar than other eating occasions among short duration sleepers. Long duration sleepers (≥9 h) exhibited lower probability of consumption of the three main meals, lower energy and nutrient intakes in the morning, lower eating frequency and shorter eating period. Irrespective of sleep duration, the largest contribution to total energy intake was in the afternoon (43-46%), followed by the evening (30-32%) and morning (22-25%) periods. In conclusion, sleep duration was associated with different dietary intakes and eating behaviours among Brazilian adults. The largest energy intakes in the afternoon and evening periods signalize the relevance to consider the timing of food consumption aside sleep duration as a target to nutritional counseling for prevention of circadian misalignment and related metabolic disturbances.

Intermittent versus continuous energy restriction on weight loss and cardiometabolic outcomes: a systematic review and meta-analysis of randomized controlled trials

Background

This systematic review and meta-analysis summarized the most recent evidence on the efficacy of intermittent energy restriction (IER) versus continuous energy restriction on weight-loss, body composition, blood pressure and other cardiometabolic risk factors.

Methods

Randomized controlled trials were systematically searched from MEDLINE, Cochrane Library, TRIP databases, EMBASE and CINAHL until May 2018. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI).

Results

Eleven trials were included (duration range 8–24 weeks). All selected intermittent regimens provided ≤ 25% of daily energy needs on “fast” days but differed for type of regimen (5:2 or other regimens) and/or dietary instructions given on the “feed” days (ad libitum energy versus balanced energy consumption). The intermittent approach determined a comparable weight-loss (WMD: − 0.61 kg; 95% CI − 1.70 to 0.47; p = 0.87) or percent weight loss (WMD: − 0.38%, − 1.16 to 0.40; p = 0.34) when compared to the continuous approach. A slight reduction in fasting insulin concentrations was evident with IER regimens (WMD = − 0.89 µU/mL; − 1.56 to − 0.22; p = 0.009), but the clinical relevance of this result is uncertain. No between-arms differences in the other variables were found.

Conclusions

Both intermittent and continuous energy restriction achieved a comparable effect in promoting weight-loss and metabolic improvements. Long-term trials are needed to draw definitive conclusions.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1748-4) contains supplementary material, which is available to authorized users.

Eating Frequency Is Not Associated with Obesity in Chinese Adults

The prevalence of overweight and obesity has been increasing globally. Recent studies suggest that eating frequency (EF) might be a factor influencing the development of overweight and obesity. This study aims to explore the association between eating frequency and obesity in Chinese adults. A cross-sectional study was conducted in Wuhan, China, from March to June 2016. A self-administered questionnaire and 24-h dietary recall were used to collect data on sociodemographic variables, lifestyle factors, nutrition knowledge, and eating frequency. Participants were divided into four groups according to eating frequency and meal timing: traditional time pattern (TTP), traditional time plus late snack pattern (TTLSP), irregular time pattern (ITP), and all-day pattern (ADP). We performed the chi-squared test and multiple logistic regression to assess associations among variables using JMP statistical software version 14.0.0 (SAS Institute Inc., Cary, NC, USA). Respondents were Chinese adults (N = 2290; range 29⁻74 years; 1162 men). Lower education level, higher food budget, and lower nutrition knowledge were associated with higher likelihood of irregular EF patterns (TTLSP, ITP, or ADP). Men, non-smokers, and participants with less physical activity, lower education level, or lower nutrition knowledge were more likely to be obese. Body mass index (BMI) categorization was significantly different among EF pattern groups (χ² = 25.40, p = 0.003); however, this association was no longer significant in the regression model after adjustment for age, sex, education, smoking, food budget, nutrition knowledge, and physical activity. Thus, EF is not associated with obesity in Chinese adults.

Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease

The ability to efficiently adapt metabolism by substrate sensing, trafficking, storage, and utilization, dependent on availability and requirement, is known as metabolic flexibility. In this review, we discuss the breadth and depth of metabolic flexibility and its impact on health and disease. Metabolic flexibility is essential to maintain energy homeostasis in times of either caloric excess or caloric restriction, and in times of either low or high energy demand, such as during exercise. The liver, adipose tissue, and muscle govern systemic metabolic flexibility and manage nutrient sensing, uptake, transport, storage, and expenditure by communication via endocrine cues. At a molecular level, metabolic flexibility relies on the configuration of metabolic pathways, which are regulated by key metabolic enzymes and transcription factors, many of which interact closely with the mitochondria. Disrupted metabolic flexibility, or metabolic inflexibility, however, is associated with many pathological conditions including metabolic syndrome, type 2 diabetes mellitus, and cancer. Multiple factors such as dietary composition and feeding frequency, exercise training, and use of pharmacological compounds, influence metabolic flexibility and will be discussed here. Last, we outline important advances in metabolic flexibility research and discuss medical horizons and translational aspects.

Impact of Dietary, Socioeconomic, and Physical Factors on Obese and Overweight Schoolchildren Living in Sidi-Bel-Abbes (West of Algeria) and Ain Defla (Centre)

Background and aims: The aim of the current study was to assess the impact of environmental factors; food, socio-economic, and physical activity, on a group of obese children living in Ain-Defla (Center Algeria) and Sidi-Bel-Abbes (West Algeria).

Material and methods: The protocol was carried out on a cohort of 125 school children aged of 5 to 11 years, including 64 boys and 61 girls, and 139 school children, including 93 boys and 46 girls in Ain Defla and Sidi-Bel-Abbes respectively. Concerning the classification of obesity and overweight, we referred to the International Obesity Task Force and the French References' curves.

Results: Regarding dietary intake our results showed that 34% of students from both regions took their breakfast, compared to 66% who did not take. Furthermore, 73% of students skipped at least one meal, however 23% respected meals frequency i.e. 4 meals a day. Regarding socio-economic factors and physical activity, our findings showed that obesity rates were high (36%) among children whose fathers are workers. However, for mothers who are housewives, obesity increases among their children (88%). The relationship was reversed between the parents' education level and the Body Mass Index. We found an opposite relationship between Body Mass Index and physical activity, and investigated children use screen devices for long time periods.

Conclusions: Our study showed a positive relationship between obesity and overweight and environmental factors.

Temporal eating patterns: associations with nutrient intakes, diet quality, and measures of adiposity

Background: Some evidence suggests that higher energy intake (EI) later in the day is associated with poor diet quality and obesity. However, EI at one eating occasion (EO) is also dependent on EI at surrounding EOs. Studies that examine the distribution of EOs across the day are rare.Objective: The aim of this study was to examine associations between temporal eating patterns, nutrient intakes, diet quality, and measures of adiposity in a representative sample of Australian adults.Design: Dietary data from two 24-h recalls collected during the cross-sectional 2011-2012 Australian National Nutrition and Physical Activity Survey were analyzed (n = 4544 adults, aged ≥19 y). Temporal eating patterns, based on the distribution of EOs across the day, were determined by using latent class analysis. Diet quality estimated adherence to healthy eating recommendations and was assessed by using the 2013 Dietary Guidelines Index (DGI). Multivariate regression models assessed associations between temporal eating patterns, nutrient intakes, diet quality, and adiposity (body mass index, waist circumference, weight status, and central weight status). Models were adjusted for potential confounders and energy misreporting.Results: Three patterns, labeled "conventional," "later lunch," and "grazing," were identified. Compared with a "conventional" or "later lunch" pattern, men and women with a "grazing" pattern had lower DGI scores and higher intakes of discretionary (noncore) foods (P < 0.05). Among women, the "grazing" pattern was associated with overweight or obesity (OR: 1.57; 95% CI: 1.15, 2.13) and central overweight or obesity (OR: 1.73; 95% CI: 1.19, 2.50). These associations were attenuated after the exclusion of energy misreporters and adjustment for total EI.Conclusions: This study found that a "grazing" temporal eating pattern was modestly but significantly associated with poorer diet quality and adiposity among women, after adjustment for covariates and energy misreporting. Future research should consider the impact of energy misreporting on the relation between temporal eating patterns and adiposity. This secondary analysis was registered at anzctr.org.au as ACTRN12617001029381.

Objective quantification of the food proximity effect on grapes, chocolate and cracker consumption in a Swedish high school. A temporal analysis

Close food proximity leads to increased short-term energy intake, potentially contributing to the long-term development of obesity. However, its precise effects on eating behaviour are still unclear, especially with food available for extended periods of time. This study involved two similar high school student groups (15–17 years old), which had ad libitum access to grapes, chocolates and crackers during an hour-long experimental session. In the distal condition the foods were placed 6 meters away from the students (n = 24), in contrast to the proximal condition (n = 17) were the food was placed near the students. The identification of the type and the quantification of the amount of each food selected, for each individual serving, was facilitated through use of food scales and video recording. In the proximal condition individuals served themselves grapes and crackers more often and consumed more chocolate than in the distal condition. In total, participants in the proximal condition ingested significantly more energy (726 kcal vs. 504 kcal; p = 0.029), without reporting higher fullness. Food proximity also affected the temporal distribution of servings, with the first five minutes of the sessions corresponding to 53.1% and 45.6% of the total energy intake for the distal and proximal conditions, respectively. After the first five minutes, the servings in the distal condition were strongly clustered in time, with many students getting food together. In the proximal condition however, students displayed an unstructured pattern of servings over time. In conclusion, this study strengthens past evidence regarding the important role of food proximity on individual energy intake and, for the first time, it associates continuous food proximity to the emergence of unstructured eating over time. These conclusions, expanded upon by future studies, could support the creation of meaningful intervention strategies based on spatially and temporally controlled food availability.

Prolonged Nightly Fasting and Breast Cancer Prognosis

IMPORTANCE

Rodent studies demonstrate that prolonged fasting during the sleep phase positively influences carcinogenesis and metabolic processes that are putatively associated with risk and prognosis of breast cancer. To our knowledge, no studies in humans have examined nightly fasting duration and cancer outcomes.

OBJECTIVE

To investigate whether duration of nightly fasting predicted recurrence and mortality among women with early-stage breast cancer and, if so, whether it was associated with risk factors for poor outcomes, including glucoregulation (hemoglobin A1c), chronic inflammation (C-reactive protein), obesity, and sleep.

DESIGN, SETTING, AND PARTICIPANTS

Data were collected from 2413 women with breast cancer but without diabetes mellitus who were aged 27 to 70 years at diagnosis and participated in the prospective Women's Healthy Eating and Living study between March 1, 1995, and May 3, 2007. Data analysis was conducted from May 18 to October 5, 2015.

EXPOSURES

Nightly fasting duration was estimated from 24-hour dietary recalls collected at baseline, year 1, and year 4.

MAIN OUTCOMES AND MEASURES

Clinical outcomes were invasive breast cancer recurrence and new primary breast tumors during a mean of 7.3 years of study follow-up as well as death from breast cancer or any cause during a mean of 11.4 years of surveillance. Baseline sleep duration was self-reported, and archived blood samples were used to assess concentrations of hemoglobin A1c and C-reactive protein.

RESULTS

The cohort of 2413 women (mean [SD] age, 52.4 [8.9] years) reported a mean (SD) fasting duration of 12.5 (1.7) hours per night. In repeated-measures Cox proportional hazards regression models, fasting less than 13 hours per night (lower 2 tertiles of nightly fasting distribution) was associated with an increase in the risk of breast cancer recurrence compared with fasting 13 or more hours per night (hazard ratio, 1.36; 95% CI, 1.05-1.76). Nightly fasting less than 13 hours was not associated with a statistically significant higher risk of breast cancer mortality (hazard ratio, 1.21; 95% CI, 0.91-1.60) or a statistically significant higher risk of all-cause mortality (hazard ratio, 1.22; 95% CI, 0.95-1.56). In multivariable linear regression models, each 2-hour increase in the nightly fasting duration was associated with significantly lower hemoglobin A1c levels (β = -0.37; 95% CI, -0.72 to -0.01) and a longer duration of nighttime sleep (β = 0.20; 95% CI, 0.14-0.26).

CONCLUSIONS AND RELEVANCE

Prolonging the length of the nightly fasting interval may be a simple, nonpharmacologic strategy for reducing the risk of breast cancer recurrence. Improvements in glucoregulation and sleep may be mechanisms linking nightly fasting with breast cancer prognosis.

Temporal eating patterns: a latent class analysis approach

Background

There is some evidence that large energy intakes towards the end of the day are associated with adverse health outcomes, however, studies of temporal eating patterns across the day are rare. This study examines the temporal eating patterns of Australian adults using latent class analysis (LCA), as a novel approach.

Methods

Dietary data (n = 2402 men and n = 2840 women, ≥19 years) from two 24-h recalls collected during the 2011–12 Australian National Nutrition and Physical Activity Survey were analyzed. LCA was performed to identify distinct temporal eating patterns based on whether or not an eating occasion (EO) occurred within each hour of the day. F and adjusted-chi² tests assessed differences in sociodemographic and eating patterns (e.g., meal, snack and EO frequency) between latent classes.

Results

Three patterns, labelled “Conventional” (men: 43%, women: 41%), “Later lunch” (men: 34%, women: 34%) and “Grazing” (men: 23%, women: 25%) were identified. Men and women with a “Grazing” pattern were significantly younger (P < 0.001) and a higher proportion were from major cities (P < 0.01) and were not married (men only, P = 0.01), compared to the “Conventional” and “Later lunch” patterns. The “Grazing” pattern was also characterized by a higher EO frequency (P < 0.01) and snack frequency (P < 0.001) and consumption of a higher proportion of total energy intake from snacks but a lower proportion of total energy intake from meals (P < 0.001).

Conclusions

This study identified three distinct temporal eating patterns in adults that varied by age, EO frequency, snack frequency and energy intake pattern. LCA is a useful approach to capture differences in EO timing across the day. Future research should examine associations between temporal eating patterns and health.

Maternal Circadian Eating Time and Frequency Are Associated with Blood Glucose Concentrations during Pregnancy

BACKGROUND

Synchronizing eating schedules to daily circadian rhythms may improve metabolic health, but its association with gestational glycemia is unknown.

OBJECTIVE

This study examined the association of maternal night-fasting intervals and eating episodes with blood glucose concentrations during pregnancy.

METHODS

This was a cross-sectional study within a prospective cohort in Singapore. Maternal 24-h dietary recalls, fasting glucose, and 2-h glucose concentrations were ascertained at 26-28 wk gestation for 1061 women (aged 30.7 ± 5.1 y). Night-fasting intervals were based on the longest fasting duration during the night (1900-0659). Eating episodes were defined as events that provided >50 kcal, with a time interval between eating episodes of ≥15 min. Multiple linear regressions with adjustment for confounders were conducted.

RESULTS

Mean ± SD night-fasting intervals and eating episodes per day were 9.9 ± 1.6 h and 4.2 ± 1.3 times/d, respectively; fasting and 2-h glucose concentrations were 4.4 ± 0.5 and 6.6 ± 1.5 mmol/L, respectively. In adjusted models, each hourly increase in night-fasting intervals was associated with a 0.03 mmol/L decrease in fasting glucose (95% CI: -0.06, -0.01 mmol/L), whereas each additional daily eating episode was associated with a 0.15 mmol/L increase in 2-h glucose (95% CI: 0.03, 0.28 mmol/L). Conversely, night-fasting intervals and daily eating episodes were not associated with 2-h and fasting glucose, respectively.

CONCLUSIONS

Increased maternal night-fasting intervals and reduced eating episodes per day were associated with decreased fasting glucose and 2-h glucose, respectively, in the late-second trimester of pregnancy. This points to potential alternative strategies to improve glycemic control in pregnant women. This study was registered at www.clinicaltrials.gov as NCT01174875.

Meal frequency and timing: impact on metabolic disease risk

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of the most recent human intervention trials that have examined the impact of meal frequency or meal timing on metabolic disease risk factors.

RECENT FINDINGS

Findings from intervention studies published over the past 12 months indicate that weight loss may be more pronounced with decreased meal frequency (two meals per day) versus increased meal frequency (six meals per day) under hypocaloric conditions. However, under isocaloric conditions, no effect on body weight was noted. Plasma lipid concentrations and glucoregulatory factors (fasting glucose, insulin, and insulin sensitivity) were not affected by alterations in meal frequency. As for meal timing, delaying the lunchtime meal by 3.5 h (from 1.30 p.m. to 4.30 p.m.) has no impact on body weight, but may impair glucose tolerance in young healthy adults.

SUMMARY

In sum, altering meal frequency has little impact on body weight, plasma lipids, or glucoregulatory factors, whereas eating the majority of calories later in the day may be detrimental for glycemic control. These preliminary findings, however, still require confirmation by longer term, larger scale controlled trials.

Meal patterns across ten European countries - results from the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study

OBJECTIVE

To characterize meal patterns across ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study.

DESIGN

Cross-sectional study utilizing dietary data collected through a standardized 24 h diet recall during 1995-2000. Eleven predefined intake occasions across a 24 h period were assessed during the interview. In the present descriptive report, meal patterns were analysed in terms of daily number of intake occasions, the proportion reporting each intake occasion and the energy contributions from each intake occasion.

SETTING

Twenty-seven centres across ten European countries.

SUBJECTS

Women (64 %) and men (36 %) aged 35-74 years (n 36 020).

RESULTS

Pronounced differences in meal patterns emerged both across centres within the same country and across different countries, with a trend for fewer intake occasions per day in Mediterranean countries compared with central and northern Europe. Differences were also found for daily energy intake provided by lunch, with 38-43 % for women and 41-45 % for men within Mediterranean countries compared with 16-27 % for women and 20-26 % for men in central and northern European countries. Likewise, a south-north gradient was found for daily energy intake from snacks, with 13-20 % (women) and 10-17 % (men) in Mediterranean countries compared with 24-34 % (women) and 23-35 % (men) in central/northern Europe.

CONCLUSIONS

We found distinct differences in meal patterns with marked diversity for intake frequency and lunch and snack consumption between Mediterranean and central/northern European countries. Monitoring of meal patterns across various cultures and populations could provide critical context to the research efforts to characterize relationships between dietary intake and health.

Impact of intermittent fasting on glucose homeostasis

PURPOSE OF REVIEW

This article provides an overview of the most recent human trials that have examined the impact of intermittent fasting on glucose homeostasis.

RECENT FINDINGS

Our literature search retrieved one human trial of alternate day fasting, and three trials of Ramadan fasting published in the past 12 months. Current evidence suggests that 8 weeks of alternate day fasting that produces mild weight loss (4% from baseline) has no effect on glucose homeostasis. As for Ramadan fasting, decreases in fasting glucose, insulin, and insulin resistance have been noted after 4 weeks in healthy normal weight individuals with mild weight loss (1-2% from baseline). However, Ramadan fasting may have little impact on glucoregulatory parameters in women with polycystic ovarian syndrome who failed to observe weight loss.

SUMMARY

Whether intermittent fasting is an effective means of regulating glucose homeostasis remains unclear because of the scarcity of studies in this area. Large-scale, longer-term randomized controlled trials will be required before the use of fasting can be recommended for the prevention and treatment of metabolic diseases.

Free-choice high-fat diet alters circadian oscillation of energy intake in adolescent mice: role of prefrontal cortex

PURPOSE

Our aim was to characterize the effect of an unfamiliar high-fat diet (HFD) on circadian feeding behaviour, plasma parameters, body weight (BW), and gene expression in the prefrontal cortex (PFC) of adolescent male mice. To this end, mice were allowed to consume a HFD during 48 h, but one group was allowed a free choice of HFD or normal chow (FC-HFD), while the other was restricted to a non-optional unfamiliar HFD feeding (NOP-HFD).

METHODS

Energy intake was monitored at 6-h intervals during 48 h. Mice cohorts were killed at 6-h intervals after 48-h dietary treatment, and PFC samples dissected for RT-PCR analysis.

RESULTS

Mice on the FC-HFD protocol avoided eating the standard chow, showed lower energy intake and lower BW increase than NOP-HFD mice. All animals with access to HFD exhibited nocturnal overeating, but diurnal hyperphagia was more prominent in the FC-HFD cohort. A robust increase in tyrosine hydroxylase (Th) gene expression was detected specifically during the light period of the circadian cycle in FC-HFD mice. In contrast, both protocols similarly up-regulated the expression of cytosolic malic enzyme (Me1), which is very sensitive to HFD.

CONCLUSION

Our data show that the PFC participates in driving motivational feeding during HFD-evoked hyperphagia and also suggest that sensory neural pathways might be relevant for the onset of eating disorders and overweight. Moreover, we have observed that animals that had the possibility of choosing between standard chow and HFD were more hyperphagic and specifically displayed an overexpression of the tyrosine hydroxylase gene.