Higher 24-h respiratory quotient and higher spontaneous physical activity in nighttime eaters

Dietary characteristics associated with the risk of non-alcoholic fatty liver disease and metabolic dysfunction-associated steatotic liver disease in non-obese Japanese participants: A cross-sectional study

Background and Aim

Dietary characteristics associated with non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) in non-obese patients remain to be elucidated. This study examined the association of NAFLD and MASLD with dietary characteristics according to obesity status.

Methods

We performed a cross-sectional study of 15 135 participants (n = 7568 men and 7567 women) aged 35-74 years using data of annual health checks between 2008 and 2020. Obesity was defined as BMI ≥ 25 kg/m2. Diagnosis of fatty liver was based on abdominal ultrasonography. Fatty-liver-related dietary characteristics were assessed using a self-administered questionnaire.

Results

For non-obese participants, NAFLD was found in 31.0% of men and 19.4% of women. Non-obese MASLD was found in 27.6% of men and 18.1% of women. Multivariable-adjusted stepwise logistic regression analysis indicated that, in males, both non-obese NAFLD and non-obese MASLD were significantly and negatively associated with "often eat sesame/nuts", and positively associated with "often eat noodles/rice bowl" and "often eat evening meal" (P < 0.05). For non-obese women, both NAFLD and MASLD were significantly and positively associated with "often eat sweet buns/bread with fillings" (P < 0.05). Adjusted analyses showed that all dietary characteristics were not significantly associated with the risk of NAFLD/MASLD in obese men and women.

Conclusion

This cross-sectional study indicates the existence of sex and obesity differences in the association of NAFLD and MASLD with dietary characteristics. Our findings suggest that some dietary characteristics are associated with NAFLD and MASLD prevalence in non-obese Japanese participants.

Night eating habits, sleep quality, and depression, are they associated with vitamin D status?

INTRODUCTION

In addition to the well-established roles of vitamin D on bone health, it also appears to be an effective factor on mental health and circadian behaviors, that include eating and sleeping habits.

OBJECTIVE

This study aimed to assess the association between vitamin D status with night eating habits, sleep quality and depression in female college students.

MATERIALS AND METHODS

This cross-sectional study studied healthy female students from Shiraz University of Medical Sciences, Iran. Demographic and anthropometric information as well as data on sleep quality and depression were recorded and serum levels of 25-hydroxyvitamin D were measured. A 3-day food record questionnaire was completed to assess night eating habits. Data analyses were undertaken using Chi-square, Mann-Whitney U test and logistic regression. A P-value of <0.05 was considered significant.

RESULTS

The study participants comprised of 272 female students with median (Inter Quartile Range) age of 22 (21-24) years. The majority of the participants (82.3 %) were classified as night eaters, who had higher rates of poor sleep quality compared to non-night eaters (P < 0.05). With 1 ng/ml increase in serum levels of 25-hydroxyvitamin D, the odds of being a night eater fell by 3 % (OR = 0.97; 95%CI = 0.95, 0.99), and the odds of having depression or poor sleep quality decreased by 5 % (OR = 0.95; 95%CI = 0.93, 0.97) and 6 % (OR = 0.94; 95%CI = 0.91, 0.97), respectively.

CONCLUSION

There was an inverse association between serum 25-hydroxyvitamin D level with night eating habits, depression and poor sleep quality. This association needs be confirmed using cohort and interventional studies.

Delayed Eating Schedule Raises Mean Glucose Levels in Young Adult Males: a Randomized Controlled Cross-Over Trial

BACKGROUND

Misalignment of meals to the biological clock may cause adverse effects on glucose metabolism. However, the effects of repeated different eating schedules (early compared with late) on glucose concentration throughout the day are poorly understood.

OBJECTIVES

We examined the effects of different eating schedules on the 24-h glucose response using a continuous glucose monitor (CGM).

METHODS

Eight young adult males (age, 20.9 ± 3.4 y; body mass index: 21.3 ± 1.8 kg/m²) each followed 2 different eating schedules (early [08:30, 13:30, and 19:30] and late [12:00, 17:00, and 23:00]) in random order. These diet interventions were conducted for 8 d, with an experimental period of 3 d and 2 nights (from dinner on day 7) after 7 d of free living. The 3 meals in each intervention were nutritionally equivalent (55% carbohydrate, 15% protein, and 30% fat). The 24-h mean interstitial glucose concentration on day 8 was obtained under controlled conditions using the CGM (primary outcome). These concentrations were compared among the following 3 schedules using Dunnett's test, with the early eating schedule as reference (1 compared with 2 and 1 compared with 3): 1) early eating schedule (control), 2) late eating schedule according to the clock time (08:00 on day 8 to 08:00 on day 9), and 3) late eating schedule according to the time elapsed since the first meal for 24 h.

RESULTS

The 24-h mean ± SD interstitial glucose concentrations when participants followed the late eating schedule were higher than those when they followed the early eating schedule in terms of clock time (91.2 ± 2.9 compared with 99.2 ± 4.6 mg/dL, P = 0.003) and time elapsed (91.2 ± 2.9 compared with 98.3 ± 3.8 mg/dL, P < 0.001).

CONCLUSIONS

A late eating schedule increases the mean 24-h interstitial glucose concentration in young adult males. This insight will have useful implications in determining meal timings, especially for those with conditions such as diabetes.

[Sleep quality, emotional and behavioral disturbances, and eating behavior in adolescents with obesity: a network analysis-based model]

OBJECTIVE

To attempt to identify persistent associations between sleep quality, symptoms of emotional and behavioral disturbances, and characteristics of eating behavior in obese adolescents based on a network analysis.

MATERIAL AND METHODS

The study included 194 adolescents, aged 12-17 years (76 girls, 118 boys), with a confirmed diagnosis of obesity due to excess calories (ICD-10 code E66.0). Sleep quality was studied on the basis of the Adolescent Sleep Wake Scale (ASWS), emotional and behavioral disturbances were assessed with the Achenbach Youth Self-Report for Ages 11-18 (YSR), eating behavior - with the Dutch Eating Behavior Questionnaire (DEBQ). Network analysis was used to identify the most significant and stable associations between the studied indicators.

RESULTS

The association of poor sleep quality with manifestations of disinhibited behavior in the form of violations of the rules of behavior, aggressiveness, and impaired attention was revealed. Positive correlations between the manifestations of disinhibited behavior (primarily, rule-breaking behavior) and emotional eating behavior, which, in turn, had a positive relationship with external and a negative relationship with restrictive eating behavior, were noted. The disinhibited adolescent behavior is linked with uncontrolled food intake, which can contribute to the development of obesity.

CONCLUSION

Impaired sleep quality, symptoms of emotional and behavioral disorders, and eating disorders in obese adolescents present a stable and specific clinical pattern that should be taken into account when justifying therapy.

Food insecurity is associated with higher respiratory quotient and lower glucagon-like peptide 1

OBJECTIVE

Food insecurity is known to be associated with obesity, but its association with physiological measures is unclear. Therefore, it was hypothesized that, compared with food-secure individuals, those with food insecurity would have higher 24-hour energy expenditure (EE [kilocalories per day]) and 24-hour respiratory quotient (RQ [ratio]). Subsequently, hormones involved in appetite regulation, substrate oxidation, and EE were explored.

METHODS

A total of 113 healthy participants without diabetes (75 men; mean [SD], age 40 [12] years; BMI 30 [8] kg/m² ) were included in this analysis. Participants completed the Food Security Short Form, underwent a dual-energy x-ray absorptiometry scan, and spent 24 hours in a human respiratory chamber following a weight-maintaining diet.

RESULTS

Compared with individuals with food security, participants with food insecurity had no difference in 24-hour EE. However, they had higher carbohydrate oxidation rates (p = 0.03) and lower lipid oxidation rates (p = 0.02), resulting in higher 24-hour RQ (p < 0.01). They also had lower fasting glucagon-like peptide 1 (p = 0.03) concentrations.

CONCLUSIONS

Food insecurity is associated with higher 24-hour RQ and lower fasting glucagon-like peptide 1 concentrations, metabolic and hormonal differences previously shown to drive greater calorie intake in the setting of unrestricted food availability. These findings therefore provide new insight into the paradoxical link between restricted food access and increased adiposity.

Is chronotype associated with dietary intake and weight gain during pregnancy? A prospective and longitudinal study

OBJECTIVES

The effects of chronotype on dietary intake and weight gain during pregnancy have not been addressed in the literature. The aim of this study was to analyze the effect of chronotype on eating patterns, energy, and macronutrient intake and distribution, as well as weight gain during pregnancy.

METHODS

This was a prospective cohort study carried out with 100 pregnant women in the first, second, and third gestational trimesters. Dietary intake was assessed by three 24-h dietary recalls in each trimester, totaling nine recalls. Energy and macronutrient intake and distribution were evaluated at meals throughout the day. Chronotype was derived from midsleep time on free days, and the scores obtained were categorized into tertiles. Recommendations from the Institute of Medicine were used to assess the adequacy of weight gain. Generalized estimating equation models were used to determine the effects of chronotype and gestational trimester on eating patterns, daily energy, macronutrient distribution, and weight gain.

RESULTS

Pregnant women with values for midsleep time on free days indicative of eveningness have breakfast later and also have higher energy and carbohydrate intake at dinner than "morning" women. Pregnant "morning" women showed better diet quality in terms of milk and dairy and saturated fat. Also, despite the tendency for all tertiles to gain excess weight during pregnancy, we found that pregnant women with a tendency to eveningness had worse adequacy of gestational weight gain in the third trimester than "morning" women (2.24 ± 0.25 versus 1.22 ± 0.14, P < 0.001).

CONCLUSION

Pregnant women with a tendency to eveningness consume breakfast later in the day and exhibit greater consumption of energy and carbohydrates in the evening, as well as a worse standard of gestational weight gain in the third trimester. Our results emphasize the importance of considering chrononutrition variables in prenatal nutritional guidelines to promote maternal and fetal health.

What Is the Impact of Energy Expenditure on Energy Intake?

Coupling energy intake (EI) to increases in energy expenditure (EE) may be adaptively, compensatorily, or maladaptively leading to weight gain. This narrative review examines if functioning of the homeostatic responses depends on the type of physiological perturbations in EE (e.g., due to exercise, sleep, temperature, or growth), or if it is influenced by protein intake, or the extent, duration, timing, and frequency of EE. As different measures to increase EE could convey discrepant neuronal or humoral signals that help to control food intake, the coupling of EI to EE could be tight or loose, which implies that some ways to increase EE may have advantages for body weight regulation. Exercise, physical activity, heat exposure, and a high protein intake favor weight loss, whereas an increase in EE due to cold exposure or sleep loss likely contributes to an overcompensation of EI, especially in vulnerable thrifty phenotypes, as well as under obesogenic environmental conditions, such as energy dense high fat—high carbohydrate diets. Irrespective of the type of EE, transient elevations in the metabolic rate seem to be general risk factors for weight gain, because a subsequent decrease in energy requirement is not compensated by an adequate adaptation of appetite and EI.

Pre-Sleep Casein Supplementation, Metabolism, and Appetite: A Systematic Review

Protein intake is an important factor for augmenting the response to resistance training in healthy individuals. Although food intake can help with anabolism during the day, the period of time during sleep is typically characterized by catabolism and other metabolic shifts. Research on the application of nighttime casein protein supplementation has introduced a new research paradigm related to protein timing. Pre-sleep casein supplementation has been attributed to improved adaptive response by skeletal muscle to resistance training through increases in muscle protein synthesis, muscle mass, and strength. However, it remains unclear what the effect of this nutritional strategy is on non-muscular parameters such as metabolism and appetite in both healthy and unhealthy populations. The purpose of this systematic review is to understand the effects of pre-sleep casein protein on energy expenditure, lipolysis, appetite, and food intake in both healthy and overweight or obese individuals. A systematic review following PRISMA guidelines was conducted in CINAHL, Cochrane, and SPORTDiscus during March 2021, and 11 studies met the inclusion criteria. A summary of the main findings shows limited to no effects on metabolism or appetite when ingesting 24-48 g of casein 30 min before sleep, but data are limited, and future research is needed to clarify the relationships observed.

High carbohydrate diet ingestion increases post-meal lipid synthesis and drives respiratory exchange ratios above 1

Locusts have been reported to elevate metabolic rate in response to high carbohydrate diets; this conclusion was based on metabolic rates calculated from CO₂ production, a common practice for insects. However, respiratory exchange ratio (RER, CO₂ production divided by O₂ consumption) can rise above 1 as a result of de novo lipid synthesis, providing an alternative possible explanation of the prior findings. We studied the relationship between macronutrient ingestion, RER and lipid synthesis using South American locusts (Schistocerca cancellata) reared on artificial diets varying in protein:carbohydrate (p:c) ratio. RER increased and rose above 1 as dietary p:c ratio decreased. Lipid accumulation rates were strongly positively correlated with dietary carbohydrate content and ingestion. RERs above 1 were only observed for animals without food in the respirometry chamber, suggesting that hormonal changes after a meal may drive lipid synthesis. Schistocerca cancellata does not elevate metabolic rate on low p:c diets; in fact, the opposite trend was observed.

Chrononutrition during Pregnancy: A Review on Maternal Night-Time Eating

Evidence from women working night shifts during pregnancy indicates that circadian rhythm disruption has the potential to adversely influence pregnancy outcomes. In the general population, chronodisruption with the potential to affect pregnancy outcomes may also be seen in those with high energy intakes in the evening or at night. However, maternal night eating during pregnancy remains understudied. This narrative review provides an overview of the prevalence, contributing factors, nutritional aspects and health implications of night eating during pregnancy. We derived evidence based on cross-sectional studies and longitudinal cohorts. Overall, night eating is common during pregnancy, with the estimated prevalence in different populations ranging from 15% to 45%. The modern lifestyle and the presence of pregnancy symptoms contribute to night eating during pregnancy, which is likely to coexist and may interact with multiple undesirable lifestyle behaviors. Unfavorable nutritional characteristics associated with night eating have the potential to induce aberrant circadian rhythms in pregnant women, resulting in adverse metabolic and pregnancy outcomes. More research, particularly intervention studies, are needed to provide more definite information on the implications of night eating for mother-offspring health.

Assessing established BMI variants for a role in nighttime eating behavior in robustly phenotyped Southwestern American Indians

BACKGROUND/OBJECTIVES

Nighttime eating (NE) behavior has a genetic component and predicts weight gain. We hypothesized that some genetic variants, which affect NE would also show an effect on body mass index (BMI). We aimed to determine which known BMI variants associate with NE in Southwestern American Indians (SWAIs), who are at elevated risk for obesity.

METHODS

Known BMI variants from the GIANT-UK Biobank meta-analysis (N = 700,000) were analysed in SWAIs characterized for NE during an inpatient 3-day protocol. Variants were analysed for association with NE using whole-genome sequence data from 50 SWAIs (23 cases and 27 controls) and selected variants were genotyped in an additional 32 SWAIs (13 NE cases and 19 controls). Variants associated with NE in a meta-analysis of the two SWAI samples were further analysed for association with nightly caloric intake and functionality in hypothalamus, pituitary, and adrenal tissues.

RESULTS

Variants were identified where the allele that associated with increased BMI in the GIANT-UK Biobank meta-analysis (P ≤ 1 × 10^-8) also had a P < 0.01 for increased NE in the SWAI meta-analysis. These variants were captured by six tagSNPs. Comparison of the nightly calorie intake by genotype and eQTL data from relevant tissues highlighted rs3753612 upstream of HCRTR1.

CONCLUSIONS

Our strategy led to the HCRTR1 locus, which has previously been linked to sleep regulation and feeding. Although this is an intriguing candidate gene for NE, further studies in larger samples and different populations are required to validate the role of HCRTR1 in NE.

Higher energy intake at night effects daily energy distribution and contributes to excessive weight gain during pregnancy

OBJECTIVE

The aim of this study was to analyze the effect of nighttime energy intake on daily energy and macronutrient distribution and weight gain during pregnancy.

METHODS

This was a prospective cohort study carried out with 100 pregnant women and the data collection occurred once per trimester. A dietary intake was assessed by three 24-h dietary recalls in each trimester, totaling nine dietary recalls. The distribution of energy and macronutrient intake was evaluated at meals throughout the day in each trimester and overall pregnancy. Women were classified as having "lower" or "higher" nighttime intake (1900 to 0559) if consumption in this period were below or above the median of the population, respectively, for at least two trimesters. Recommendations from the Institute of Medicine were used to assess the adequacy of weight gain. Generalized estimating equation models were used to determine the effects of nighttime intake and gestational trimesters on daily energy distribution and weight gain.

RESULTS

In overall pregnancy, the higher group consumed a higher percentage of energy and macronutrients in the evening meals, and less energy, proteins, and lipids in morning meals when compared with the lower group. Also, women in the higher group had greater excessive weight gain in the third trimester compared with the lower group.

CONCLUSION

Pregnant women with a higher energy intake at night had a lower percentage of energy, protein, and lipid intake in morning meals and a higher percentage of energy and macronutrient intake in the evening meals during pregnancy. A worse standard of gestational weight gain in the third trimester was also observed in pregnant women with a higher energy intake at night.

Timing of eating in adults across the weight spectrum: Metabolic factors and potential circadian mechanisms

Timing of eating is recognized as a significant contributor to body weight regulation. Disruption of sleep-wake cycles from a predominantly diurnal (daytime) to a delayed (evening) lifestyle leads to altered circadian rhythms and metabolic dysfunction. This article reviews current evidence for timed and delayed eating in individuals of normal weight and those with overweight or obesity: although some findings indicate a benefit of eating earlier in the daytime on weight and/or metabolic outcomes, results have not been uniformly consistent, and more rigorous and longer-duration studies are needed. We also review potential circadian mechanisms underlying the metabolic- and weight-related changes resulting from timed and delayed eating. Further identification of such mechanisms using deep phenotyping is required to determine targets for medical interventions for obesity and for prevention of metabolic syndrome and diabetes, and to inform clinical guidelines regarding eating schedules for management of weight and metabolic disease.

Why I eat at night: A qualitative exploration of the development, maintenance and consequences of Night Eating Syndrome

Night Eating Syndrome (NES), as a diagnosis, presents as a combination of disordered eating, sleep and mood. Patients identified as having both NES and obesity demonstrate poorer outcomes in terms of weight loss compared to those with NES only. However, research focusing on psychological factors associated with NES remains relatively underdeveloped. This study aimed to explore the relationship between NES and the experience of emotion from the perspective of patients accessing a weight management service. Ten adults who met diagnostic criteria for moderate or full NES took part in a semi-structured interview. Data were analysed using a constructivist approach to grounded theory. A core concept to emerge from the analysis was termed 'emotional hunger'; reflecting an urge or need to satiate a set of underlying unmet emotional needs. It was underpinned by the following interrelated themes: (1) Cultivating a dependency on food; (2) Relying on food to regulate emotions; (3) Understanding the significance of night-time; (4) Acknowledging the consequences of night eating. This study provides an in-depth understanding of the relationship between NES and the experience of emotion from the perspective of patients attending a weight management service. Results have potential to inform future service development, particularly around the adoption of a more holistic approach to night eating behaviours.

Deletion of the Cold Thermoreceptor TRPM8 Increases Heat Loss and Food Intake Leading to Reduced Body Temperature and Obesity in Mice

The coupling of energy homeostasis to thermoregulation is essential to maintain homeothermy in changing external environments. We studied the role of the cold thermoreceptor TRPM8 in this interplay in mice of both sexes. We demonstrate that TRPM8 is required for a precise thermoregulation in response to cold, in fed and fasting. Trpm8^-/- mice exhibited a fall of 0.7°C in core body temperature when housed at cold temperatures, and a deep hypothermia (<30°C) during food deprivation. In both situations, TRPM8 deficiency induced an increase in tail heat loss. This, together with the presence of TRPM8-sensory fibers innervating the main tail vessels, unveils a major role of this ion channel in tail vasomotor regulation. Finally, TRPM8 deficiency had a remarkable impact on energy balance. Trpm8^-/- mice raised at mild cold temperatures developed late-onset obesity and metabolic dysfunction, with daytime hyperphagia and reduction of fat oxidation as plausible causal factors. In conclusion, TRPM8 fine-tunes eating behavior and fuel utilization during thermoregulatory adjustments to mild cold. Persistent imbalances in these responses result in obesity.SIGNIFICANCE STATEMENT The thermosensitive ion channel TRPM8 is required for a precise thermoregulatory response to cold and fasting, playing an important role in tail vasoconstriction, and therefore heat conservation, as well as in the regulation of ingestive behavior and metabolic fuel selection upon cooling. Indeed, TRPM8-deficient mice, housed in a mild cold environment, displayed an increase in tail heat loss and lower core body temperature, associated with the development of late-onset obesity with glucose and lipid metabolic dysfunction. A persistent diurnal hyperphagia and reduced fat oxidation constitute plausible underlying mechanisms in the background of a deficient thermoregulatory adjustment to mild cold ambient temperatures.

Are large dinners associated with excess weight, and does eating a smaller dinner achieve greater weight loss? A systematic review and meta-analysis

There are suggestions that large evening meals are associated with greater BMI. This study reviewed systematically the association between evening energy intake and weight in adults and aimed to determine whether reducing evening intake achieves weight loss. Databases searched were MEDLINE, PubMed, Cinahl, Web of Science, Cochrane Library of Clinical Trials, EMBASE and SCOPUS. Eligible observational studies investigated the relationship between BMI and evening energy intake. Eligible intervention trials compared weight change between groups where the proportion of evening intake was manipulated. Evening intake was defined as energy consumed during a certain time - for example 18.00-21.00 hours - or self-defined meal slots - that is 'dinner'. The search yielded 121 full texts that were reviewed for eligibility by two independent reviewers. In all, ten observational studies and eight clinical trials were included in the systematic review with four and five included in the meta-analyses, respectively. Four observational studies showed a positive association between large evening intake and BMI, five showed no association and one showed an inverse relationship. The meta-analysis of observational studies showed a non-significant trend between BMI and evening intake (P=0·06). The meta-analysis of intervention trials showed no difference in weight change between small and large dinner groups (-0·89 kg; 95 % CI -2·52, 0·75, P=0·29). This analysis was limited by significant heterogeneity, and many trials had an unknown or high risk of bias. Recommendations to reduce evening intake for weight loss cannot be substantiated by clinical evidence, and more well-controlled intervention trials are needed.

Nighttime snacking is associated with risk of obesity and hyperglycemia in adults: a cross-sectional survey from Chinese adult teachers

Relationship between nighttime snack and human health conditions remains unclear. In this paper, we analyzed the association of frequency of nighttime snacking with obesity, hyperlipidemia and hyperglycemia using a Chinese teacher cohort. The Chinese teacher study contains 22,176 of the general adult population operated on in 2015. Information of nighttime snacking frequency was acquired by questionnaire. Overweight and obesity outcome were assessed by body mass index (BMI), and hypertension; hyperlipidemia and hyperglycemia were self-reported. Associations between nighttime snacking consumption and outcomes were performed with multivariat regression and further stratification analyses. We found a significant association (OR 2.11, 95% CI 1.24, 3.62;P for trend<0.001) between most frequent nighttime snacking and hyperglycemia. A remarkable association was also observed between most frequent consumption of nighttime snack and obesity (OR 3.10, 95% CI 1.63, 5.89; Pfor trend<0.001). The present results provide epidemiological evidence that consumption of nighttime snack was associated with obesity and hyperglycemia in Chinese adult teachers. However, the underlying mechanisms still need further investigation..

Specific skeletal muscle sphingolipid compounds in energy expenditure regulation and weight gain in Native Americans of Southwestern heritage

BACKGROUND/OBJECTIVES

In animal models, a role in the regulation of energy expenditure (EE) has been ascribed to sphingolipids, active components of cell membranes participating in cellular signaling. In humans, it is unknown whether sphingolipids have a role in the modulation of EE and, consequently, influence weight gain. The present study investigated the putative association of EE and weight gain with sphingolipid levels in the human skeletal muscle, a component of fat-free mass (the strongest determinant of EE), in adipose tissue and plasma.

SUBJECTS/METHODS

Twenty-four-hour EE, sleeping metabolic rate (SMR) and resting metabolic rate (RMR) were assessed in 35 healthy Native Americans of Southwestern heritage (24 male; 30.2±7.73 years). Sphingolipid (ceramide, C; sphingomyelin, SM) concentrations were measured in skeletal muscle tissue, subcutaneous adipose tissue and plasma samples. After 6.68 years (0.26-12.4 years), follow-up weights were determined in 16 participants (4 females).

RESULTS

Concentrations of C24:0, SM18:1/26:1 and SM18:0/24:1 in muscle were associated with 24-h EE (r=-0.47, P=0.01), SMR (r=-0.59, P=0.0008) and RMR (r=-0.44, P=0.01), respectively. Certain muscle sphingomyelins also predicted weight gain (for example, SM18:1/23:1, r=0.74, P=0.004). For specific muscle sphingomyelins that correlated with weight gain and EE (SM18:1/23:0, SM18:1/23:1 and SMR, r=-0.51, r=-0.41, respectively, all P<0.03; SM18:1/24:2 and RMR, r=-0.36, P=0.03), associations could be reproduced with SMR in adipose tissue (all r<-0.46, all P<0.04), though not in plasma.

CONCLUSIONS

This study provides preliminary, novel evidence, that specific muscle and adipose tissue sphingolipid compounds are associated with EE and weight gain in Native Americans of Southwestern heritage. Further studies are warranted to investigate whether sphingolipids of different body compartments act in concert to modulate energy balance in humans.

Ability to adjust nocturnal fat oxidation in response to overfeeding predicts 5-year weight gain in adults

OBJECTIVE

To determine whether metabolic responses to short-term overfeeding predict longitudinal changes in body weight.

METHODS

Twenty-four-hour energy expenditure (EE) and substrate utilization were measured at baseline in a room calorimeter following 3 days of eucaloric and hypercaloric feeding (40% excess) in a sample of lean adults (n: 34; age: 28 ± 2 y; BMI: 22 ± 3 kg/m² ). Body mass and fat mass (dual-energy x-ray absorptiometry) were measured annually for 5 years. Regression analyses examined whether changes in EE and fuel use with overfeeding predicted body weight and composition changes over 5 years.

RESULTS

Overfeeding increased EE and reduced fat oxidation when examined over the 24-hour, waking, and nocturnal periods. Absolute change in body mass over 5 years was 3.0 ± 0.6 kg (average rate of change = 0.7 ± 0.1 kg/y, P < 0.001). Lower nocturnal (but not 24-hour or waking) fat oxidation (r = -0.42, P = 0.01) and EE (r = -0.33, P = 0.05) with overfeeding were the strongest predictors of 5-year weight gain. When adjusted for covariates, changes in nocturnal fat oxidation and EE with overfeeding predicted 41% of the variance in weight change (P = 0.02).

CONCLUSIONS

Failure to maintain fat oxidation at night following a period of overfeeding appears to be associated with a metabolic phenotype favoring weight gain.

Eating behavior by sleep duration in the Hispanic Community Health Study/Study of Latinos

Sleep is an important pillar of health and a modifiable risk factor for diabetes, stroke and obesity. Little is known of diet and sleep patterns of Hispanics/Latinos in the US. Here we examine eating behavior as a function of sleep duration in a sub-sample of 11,888 participants from the Hispanic Community Health Study/Study of Latinos, a community-based cohort study of Hispanics aged 18-74 years in four US cities. Using a cross-sectional probability sample with self-report data on habitual sleep duration and up to two 24-h dietary recalls, we quantified the Alternative Healthy Eating Index (AHEI-2010) score, a measure of diet quality, and intake of selected nutrients related to cardiovascular health. Linear regression models were fit to estimate least-square means of usual nutrient intake of saturated fats, potassium density, fiber, calcium, caffeine and the AHEI-2010 score by sleep duration adjusting for age, sex, Hispanic/Latino background, income, employment status, education, depressive symptomology, and years lived in the US. Distribution of calories over the day and association with sleep duration and BMI were also examined. Short sleepers (≤6 h) had significantly lower intake of potassium, fiber and calcium and long sleepers (≥9 h) had significantly lower intake of caffeine compared to others sleepers after adjusting for covariates. However no difference in the AHEI-2010 score was seen by sleep duration. Significantly more long sleepers, compared to intermediate and short sleepers, reported having ≥30% total daily calories before bedtime. Not consuming a snack or meal within 3 h before bedtime was associated with higher AHEI-2010 scores. These findings identify novel differences in dietary patterns by sleep duration in a Hispanic/Latino cohort in the U.S. CLINICALTRIALS.

GOV IDENTIFIER

NCT02060344.

The health impact of nighttime eating: old and new perspectives

Nighttime eating, particularly before bed, has received considerable attention. Limiting and/or avoiding food before nighttime sleep has been proposed as both a weight loss strategy and approach to improve health and body composition. Indeed, negative outcomes have been demonstrated in response to large mixed meals in populations that consume a majority of their daily food intake during the night. However, data is beginning to mount to suggest that negative outcomes may not be consistent when the food choice is small, nutrient-dense, low energy foods and/or single macronutrients rather than large mixed-meals. From this perspective, it appears that a bedtime supply of nutrients can promote positive physiological changes in healthy populations. In addition, when nighttime feeding is combined with exercise training, any adverse effects appear to be eliminated in obese populations. Lastly, in Type I diabetics and those with glycogen storage disease, eating before bed is essential for survival. Nevertheless, nighttime consumption of small (~150 kcals) single nutrients or mixed-meals does not appear to be harmful and may be beneficial for muscle protein synthesis and cardiometabolic health. Future research is warranted to elucidate potential applications of nighttime feeding alone and in combination with exercise in various populations of health and disease.

Rodent models to study the metabolic effects of shiftwork in humans

Our current 24-h society requires an increasing number of employees to work nightshifts with millions of people worldwide working during the evening or night. Clear associations have been found between shiftwork and the risk to develop metabolic health problems, such as obesity. An increasing number of studies suggest that the underlying mechanism includes disruption of the rhythmically organized body physiology. Normally, daily 24-h rhythms in physiological processes are controlled by the central clock in the brain in close collaboration with peripheral clocks present throughout the body. Working schedules of shiftworkers greatly interfere with these normal daily rhythms by exposing the individual to contrasting inputs, i.e., at the one hand (dim)light exposure at night, nightly activity and eating and at the other hand daytime sleep and reduced light exposure. Several different animal models are being used to mimic shiftwork and study the mechanism responsible for the observed correlation between shiftwork and metabolic diseases. In this review we aim to provide an overview of the available animal studies with a focus on the four most relevant models that are being used to mimic human shiftwork: altered timing of (1) food intake, (2) activity, (3) sleep, or (4) light exposure. For all studies we scored whether and how relevant metabolic parameters, such as bodyweight, adiposity and plasma glucose were affected by the manipulation. In the discussion, we focus on differences between shiftwork models and animal species (i.e., rat and mouse). In addition, we comment on the complexity of shiftwork as an exposure and the subsequent difficulties when using animal models to investigate this condition. In view of the added value of animal models over human cohorts to study the effects and mechanisms of shiftwork, we conclude with recommendations to improve future research protocols to study the causality between shiftwork and metabolic health problems using animal models.

Optimal management of night eating syndrome: challenges and solutions

Night Eating Syndrome (NES) is a unique disorder characterized by a delayed pattern of food intake in which recurrent episodes of nocturnal eating and/or excessive food consumption occur after the evening meal. NES is a clinically important disorder due to its relationship to obesity, its association with other psychiatric disorders, and problems concerning sleep. However, NES often goes unrecognized by both health professionals and patients. The lack of knowledge regarding NES in clinical settings may lead to inadequate diagnoses and inappropriate treatment approaches. Therefore, the proper diagnosis of NES is the most important issue when identifying NES and providing treatment for this disorder. Clinical assessment tools such as the Night Eating Questionnaire may help health professionals working with populations vulnerable to NES. Although NES treatment studies are still in their infancy, antidepressant treatments and psychological therapies can be used for optimal management of patients with NES. Other treatment options such as melatonergic medications, light therapy, and the anticonvulsant topiramate also hold promise as future treatment options. The purpose of this review is to provide a summary of NES, including its diagnosis, comorbidities, and treatment approaches. Possible challenges addressing patients with NES and management options are also discussed.

Consuming more of daily caloric intake at dinner predisposes to obesity. A 6-year population-based prospective cohort study

BACKGROUND/OBJECTIVES

It has been hypothesized that assuming most of the caloric intake later in the day leads to metabolic disadvantages, but few studies are available on this topic. Aim of our study was to prospectively examine whether eating more of the daily caloric intake at dinner leads to an increased risk of obesity, hyperglycemia, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD).

SUBJECTS/METHODS

1245 non-obese, non-diabetic middle-aged adults from a population-based cohort underwent a 3-day food record questionnaire at enrollment. Anthropometric values, blood pressure, blood metabolic variables, and estimated liver fat were measured at baseline and at 6-year follow-up.

DESIGN

Prospective cohort study.

RESULTS

Subjects were divided according to tertiles of percent daily caloric intake at dinner. A significant increase in the incidence rate of obesity (from 4.7 to 11.4%), metabolic syndrome (from 11.1 to 16.1%), and estimated NAFLD (from 16.5 to 23.8%) was observed from the lower to higher tertile. In a multiple logistic regression model adjusted for multiple covariates, subjects in the highest tertile showed an increased risk of developing obesity (OR = 2.33; 95% CI 1.17-4.65; p = 0.02), metabolic syndrome (OR = 1.52; 95% CI 1.01-2.30; p = 0.04), and NAFLD (OR = 1.56; 95% CI 1.10-2.22; p = 0.01).

CONCLUSIONS

Consuming more of the daily energy intake at dinner is associated with an increased risk of obesity, metabolic syndrome, and NAFLD.

Influence of night-time protein and carbohydrate intake on appetite and cardiometabolic risk in sedentary overweight and obese women

The present study investigated whether whey (WH) protein, casein (CAS) protein or a carbohydrate placebo (PLA) consumed 30 min before sleep could acutely alter appetite or cardiometabolic risk the following morning. A total of forty-four sedentary overweight and obese women (BMI: 25·7-54·6 kg/m2) completed this stratified, randomised, double-blind, placebo-controlled study (WH: n 16, age 27·4 (sd 5·0) years; CAS: n 15, age 30·3 (sd 8·1) years; PLA: n 13, age 28·5 (sd 7·2) years). The participants came to the laboratory at baseline (visit 1) and again in the morning after night-time ingestion of either protein or PLA (visit 2). Visit 2 was conducted at least 48 h after visit 1. During visits 1 and 2, the following parameters were measured: appetite (hunger, satiety and desire to eat); resting metabolism; blood lipid and glucose levels; the levels of insulin, leptin, C-reactive protein, insulin-like growth factor-1, cortisol and adiponectin. Data were analysed using repeated-measures ANOVA. No group × time interactions were observed for the measured variables; however, a main effect of time was observed for increased satiety (P= 0·03), reduced desire to eat (P= 0·006), and increased insulin levels (P= 0·004) and homeostatic model assessment of insulin resistance values (P= 0·01) after the consumption of either protein or PLA. The results of the present study reveal that night-time consumption of protein or carbohydrate by sedentary overweight and obese women improves their appetite measures but negatively affects insulin levels. Long-term studies are needed to evaluate the effects of chronic consumption of low-energy snacks at night on body composition and cardiometabolic risk.

Delayed Timing of Eating: Impact on Weight and Metabolism

Animal studies of delayed eating have provided useful information regarding the potential relationship between nighttime eating and increased weight and metabolic dysregulation, which occur in the absence of increased locomotion or increased caloric intake. We first review recent studies detailing these relationships and possible mechanisms in rodents. We then examine human data showing that sleep restriction leads to increased energy intake and weight gain, followed by a review of the human phenotype of delayed eating, night eating syndrome, and its relation to weight and metabolism. Finally, we examine human experimental studies of delayed eating and discuss preliminary data that show slight weight gain, dysfunction in energy expenditure, and abnormalities in the circadian rhythms of appetitive, stress, and sleep hormones. Well-controlled, longer-term experimental studies in humans are warranted to test the effect of delayed eating without sleep restriction to clarify whether limiting or eliminating nighttime eating could lead to weight loss and significantly improve related disorders, such as diabetes and heart disease, over time.

Seasonal variation in basal metabolic rates among the Yakut (Sakha) of Northeastern Siberia

OBJECTIVES

Previous research has shown that indigenous circumpolar populations have elevated basal metabolic rates (BMRs), yet few studies have explored whether metabolic rates increase during the winter. This study addresses this gap by examining seasonal variation in BMR and its associations with thyroid function and lifestyle factors among the Yakut (Sakha) of Siberia.

METHODS

Anthropometric dimensions, BMR, and thyroid hormone levels (free triiodothyronine [fT3], free thyroxine [fT4], thyroid-stimulating hormone [TSH]) were measured on two occasions (July/August, 2009 and January 2011) on a sample of 94 Yakut (Sakha) adults (35 men, 59 women) from the rural village of Berdygestiakh, Sakha Republic, Russia.

RESULTS

Seasonal changes in BMR varied by age. Younger Yakut adults (19-49 years) showed significant elevations in winter-time BMR of 6% (P < 0.05), whereas older individuals (≥50 years) showed modest declines (2%; n.s.). Both younger and older Yakut men and women showed increased respiratory quotients during the winter. FT3 and fT4 levels significantly declined during the winter in both younger and older Yakut men and women (P < 0.05). Lifestyle factors were significant predictors of BMR variation, particularly among older men and women.

CONCLUSIONS

Among the Yakut, increased wintertime BMR was observed among younger but not older adults, whereas all adults showed sharp reductions in free thyroid hormone levels during the winter. Among men, greater participation in subsistence activities was associated with increased BMRs and greater fat oxidation. Among women, variation in food use had the strongest impact on metabolic function.

Daily physical activity patterns of children with delayed eating behaviors

Night eating syndrome (NES) is a delayed pattern of energy intake. It is unknown if symptoms associated with this syndrome are accompanied by a delayed pattern of physical activity. This study examines the relationship between physical activity patterns and delayed eating behaviors in children. Children from the QUALITY cohort (n = 269, 45% female, aged 8-11 y) completed the Night Eating Questionnaire (NEQ), which measures NES symptoms on a continuous scale and identifies single NES symptoms. Daily accelerometer data were transformed into mean counts per wear-time minute for each hour of the day. Children with high NEQ scores had higher levels of daily (p < 0.001) and evening physical activity (p = 0.05) and reached 75% of their total daily physical activity 20 minutes later than children with low NEQ scores (p < 0.05). Excessive evening snacking and a strong urge to eat in the evening or at night were the symptoms most related to these physical activity patterns. Children with delayed eating behaviors had higher levels of physical activity in the late morning and evening and a delayed physical activity pattern compared to children with no or fewer symptoms. Future research is needed to determine if physical activity plays a role in the onset or maintenance of night eating.

Nighttime snacking reduces whole body fat oxidation and increases LDL cholesterol in healthy young women

The increase in obesity and lipid disorders in industrialized countries may be due to irregular eating patterns. Few studies have investigated the effects of nighttime snacking on energy metabolism. We examined the effects of nighttime snacking for 13 days on energy metabolism. Eleven healthy women (means ± SD; age: 23 ± 1 yr; body mass index: 20.6 ± 2.6 kg/m2) participated in this randomized crossover trial for a 13-day intervention period. Subjects consumed a specified snack (192.4 ± 18.3 kcal) either during the daytime (10:00) or the night time (23:00) for 13 days. On day 14, energy metabolism was measured in a respiratory chamber without snack consumption. An oral glucose tolerance test was performed on day 15. Relative to daytime snacking, nighttime snacking significantly decreased fat oxidation (daytime snacking: 52.0 ± 13.6 g/day; nighttime snacking: 45.8 ± 14.0 g/day; P = 0.02) and tended to increase the respiratory quotient (daytime snacking: 0.878 ± 0.022; nighttime snacking: 0.888 ± 0.021; P = 0.09). The frequency of snack intake and energy intake, body weight, and energy expenditure were not affected. Total and low-density lipoprotein (LDL) cholesterol significantly increased after nighttime snacking (152 ± 26 mg/dl and 161 ± 29 mg/dl; P = 0.03 and 76 ± 20 mg/dl and 83 ± 24 mg/dl; P = 0.01, respectively), but glucose and insulin levels after the glucose load were not affected. Nighttime snacking increased total and LDL cholesterol and reduced fat oxidation, suggesting that eating at night changes fat metabolism and increases the risk of obesity.

Update on energy homeostasis and insufficient sleep

Driven by the demands and opportunities of modern life, many people habitually sleep less than 6 h a night. In the sleep clinic, chronic sleep restriction is recognized by the diagnosis of insufficient sleep syndrome (ICSD-9, 307.49-4), which is receiving increased scrutiny as a potential risk to metabolic health. Its relevance for the practicing endocrinologist is highlighted by a stream of epidemiological data that show an association of insufficient sleep with increased incidence of obesity and related morbidities. A central theme of this update is the notion that sleep loss incurs additional metabolic cost, which triggers a set of neuroendocrine, metabolic, and behavioral adaptations aimed at increasing food intake and conserving energy. Although this coordinated response may have evolved to offset the metabolic demands of extended wakefulness in natural habitats with limited food availability, it can be maladaptive in the context of a modern environment that allows many to overeat while maintaining a sedentary lifestyle without sufficient sleep. Importantly, such sleep loss-related metabolic adaptation may undermine the success of behavioral interventions based on reduced caloric intake and increased physical activity to lower metabolic risk in obesity-prone individuals. This emerging perspective is based on data from recently published human interventional studies and requires further experimental support. Nevertheless, it now seems prudent to recommend that overweight and obese individuals attempting to reduce their caloric intake and maintain increased physical activity should obtain adequate sleep and, if needed, seek effective treatment for any coexisting sleep disorders.

Night eating syndrome: a critical review of the literature

Clinical psychologists are increasingly called to participate in the treatment of obesity, a condition that affects about one-third of adults in the United States. A disorder gaining increased recognition for its role in the development and maintenance of obesity is Night Eating Syndrome (NES), a relatively novel disorder involving morning anorexia, evening hyperphagia and/or nocturnal ingestions, and insomnia. NES affects men and women from various racial groups and tends to run in families. NES tends to co-occur with mood, anxiety, eating, sleep, and substance use disorders and may have implications for weight and diabetes management. Relatively little is known about the successful treatment of NES. Limited evidence suggests that serotonergic-based pharmacological treatments may be beneficial. Psychological interventions, such as psychoeducation, eating modification, relaxation strategies, sleep hygiene, cognitive restructuring, physical activity, and social support facilitation may also yield beneficial results. The purpose of the present paper is to provide an introduction to NES, including diagnosis, clinical presentation, assessment, comorbidities, clinical implications, and pharmacological and psychological treatment approaches. Areas for further study and development are discussed. NES is an emerging area for clinical description, evaluation, and intervention.