The night-eating syndrome and obesity

Associations of meal timing and sleep duration with incidence of obesity: a prospective cohort study

OBJECTIVES

Late mealtime and short sleep are known to be associated with obesity risk due to a misaligned circadian rhythm. This study aimed to investigate the relationship between obesity and mealtime and sleep duration using the Korean Genome and Epidemiology Study (KoGES) data.

DESIGN

Longitudinally prospective cohort study.

SETTING

Population-based.

PARTICIPANTS

KoGES analysed data from 9,474 Korean adults with an average age of 54- years old at baseline.

MEASUREMENTS

Meal timing was defined as the eating occasions of the day reported by the participant eating a 24-h dietary recall method. Sleep duration was categorized as <6, 6-7, 7-8, and ≥8 h. The Cox proportional hazard model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident obesity according to meal timing, sleep duration, and nightly fasting duration.

RESULTS

During a mean follow-up of 3.5 years, 826 participants developed obesity. In the multivariable-adjusted analysis, midnight snack eating (HR, 1.20; 95% CI, 1.02-1.41) and higher energy intake from midnight snacks (HR, 1.26; 95% CI, 1.06-1.49) were associated with a higher risk of obesity. Sleeping 8 h or more (HR, 0.67; 95% CI, 0.53-0.85) was associated with a lower risk of obesity.

CONCLUSIONS

Our findings highlight the importance of meal and sleep times and suggest that healthy eating habits related to the time of day.

Association between sleep duration and quality with food intake, chrononutrition patterns, and weight gain during pregnancy

To analyse the association between sleep duration and quality with food intake, chrononutrition patterns, and weight gain during pregnancy. A prospective cohort study was conducted with 100 pregnant women. Data collection occurred once during each gestational trimester. The assessment of sleep quality and duration was performed using the Pittsburgh Sleep Quality Index. Food intake was assessed using three 24-h recalls in each trimester. Body weight was measured during the three trimesters, and height was measured only once to calculate the BMI. Linear regression analyses were performed to associate sleep duration and quality with food consumption and weight gain variables. Longer sleep duration was associated with a later dinner in the first trimester (β = 0·228, P = 0·025) and earlier in the third trimester (β = -0·223, P = 0·026), in addition to a later morning snack in the second trimester (β = 0·315, P = 0·026). Worse sleep quality was associated with higher total energy intake (β = 0·243, P = 0·044), total fat (β = 0·291, P = 0·015) and the chrononutrition variables such as a higher number of meals (β = 0·252, P = 0·037), higher energetic midpoint (β = 0·243, P = 0·044) and shorter fasting time (β = -0·255, P = 0·034) in the third trimester. Sleep quality was also associated with a higher BMI in the first trimester of pregnancy (β = 0·420, P = < 0·001). Most of the associations found in the present study show that poor sleep is associated with higher energy and fat intake and higher BMI. Longer sleep duration was associated with a later dinner in early pregnancy and an earlier dinner in late pregnancy, as well as with a later morning snack in the second trimester of pregnancy.

Temporal Dietary Pattern Cluster Membership Varies on Weekdays and Weekends but Both Link to Health

BACKGROUND

Energy and dietary quality are known to differ between weekdays and weekends. Data-driven approaches that incorporate time, amount, and duration of dietary intake have previously been used to partition participants' daily weekday dietary intake time series into clusters representing weekday temporal dietary patterns (TDPs) linked to health indicators in United States adults. Yet, neither the relationship of weekend day TDPs to health indicators nor how the TDP membership may change from weekday to weekend is known.

OBJECTIVES

This study was conducted to determine the association between TDPs on weekdays and weekend days and health indicators [diet quality, waist circumference (WC), body mass index (BMI), and obesity] and their overlap among participants.

METHODS

A weekday and weekend day 24-hour dietary recall of 9494 nonpregnant United States adults aged 20-65 years from the cross-sectional National Health and Nutrition Examination Survey 2007-2018 was used to determine the timing and amount of energy intake. Modified dynamic time warping and kernel k-means algorithm clustered participants into 4 TDPs on weekdays and weekend days. Multivariate regression models determined the associations between TDPs and health indicators, controlling for potential confounders and adjusting for the survey design and multiple comparisons. The percentages of overlap in cluster membership between TDPs on weekdays and weekend days were also determined.

RESULTS

United States adults with a TDP of evenly spaced, energy-balanced eating occasions, representing the TDP of more than one-third of all adults on weekdays and weekends, had significantly higher diet quality, lower BMI, WC, and odds of obesity when compared to those with other TDPs. Membership of most United States adults to TDPs varied from weekdays to weekends.

CONCLUSIONS

Both weekday and weekend TDPs were significantly associated with health indicators. TDP membership of most United States adults was not consistent on weekdays and weekends.

Associations between food consumption/dietary habits and the risks of obesity, type 2 diabetes, and hypertension: a cross-sectional study in Jakarta, Indonesia

BACKGROUND/OBJECTIVES

This study aimed to assess the current mean daily intake of 10 food groups, analyze the sociodemographic factors associated with food consumption, and determine the associations between food consumption/dietary intake and the prevalence rates of obesity, type 2 diabetes (T2D), and hypertension (HTN) in Jakarta, Indonesia.

SUBJECTS/METHODS

A total of 600 participants aged 20-85 yrs were included in this cross-sectional study. Food consumption and dietary habits were assessed using a food frequency questionnaire. To determine the association between food consumption/dietary habits and the abovementioned diseases, logistic regression analysis was performed.

RESULTS

The average vegetable and fruit intake was lower, while sugar and salt consumption were higher than that recommended by Indonesia's national dietary guidelines. A high intake of ultra-processed foods (UPFs) was associated with young age, men, "single" status, a high education level, and employment with a high monthly income. Obesity and T2D were positively correlated with high intakes of cereals and tubers, UPFs, sugars, fats, and oils. Conversely, an inverse association was found between legume, vegetable, and fruit consumption and obesity risk. An inverse correlation was also observed between vegetable consumption and T2D risk. Moreover, a high salt intake was inversely correlated with fruit consumption in terms of HTN risk. Non-indulgence in habitual late-night snacking and refrainment from consuming more than one dish at each meal were also negatively related to the prevalence of obesity, T2D, and HTN. Inverse correlations were also observed between the prevalence rates of T2D and HTN and abstaining from adding sugar to beverages.

CONCLUSION

Foods high in fat, sugar, and sodium were strongly associated with the risks of obesity, T2D, and HTN. Additionally, poor eating habits were also associated with disease development.

Beat the Clock: Assessment of Night Eating Syndrome and Circadian Rhythm in a Sample of Greek Adults

The night eating syndrome (NES) is characterized by excessive food intake during the evening and night hours, with 25% of the daily intake being consumed post-dinner, paired with ep-isodes of nocturnal food intake, at a frequency of more than twice weekly. The NES has been associated with a misaligned circadian rhythm related to a delay in overall food intake, increased energy and fat consumption. The present cross-sectional study aimed to assess NES in a Greek population and evaluate possible links between NES and chronotype. NES was assessed using the Night Eating Questionnaire (NEQ), and circadian rhythm, sleep and mood were evaluated with the Sleep, Circadian Rhythms, and Mood (SCRAM) questionnaire. A total of 533 adults participated in the study. A relatively high prevalence of NES was revealed, with more than 8.1% (NEQ ≥ 30) of the participants reporting experiencing NES symptoms, depending on the NEQ threshold used. Most participants had the intermediate chronotype. NEQ score was positively associated with the morning chronotype, and SCRAM was negatively related to "Good Sleep". Each point increment in the depression score was associated with 6% higher odds of NES. The early identification of NES gains importance in clinical practice, in a collective effort aiming to reduce NES symptomatology and its detrimental health effects.

Tyrosine Hydroxylase Knockdown at the Hypothalamic Supramammillary Nucleus Area Induces Obesity and Glucose Intolerance

INTRODUCTION

The supramammillary nucleus (SuMN) exerts influences on a wide range of brain functions including feeding and feeding-independent fuel metabolism. However, which specific neuronal type(s) within the SuMN manifest this influence has not been delineated. This study investigated the effect of SuMN tyrosine hydroxylase (TH) (rate-limiting enzyme in dopamine synthesis) knockdown (THx) on peripheral fuel metabolism.

METHODS

SuMN-THx was accomplished using a virus-mediated shRNA to locally knockdown TH gene expression at the SuMN. The impact of SuMN-THx was examined over 35-72 days in rats least prone to developing metabolic syndrome (MS) - female Sprague-Dawley rats resistant to the obesogenic effect of high fat diet (HFDr) and fed regular chow (RC) - upon body weight/fat, feeding, glucose tolerance, and insulin sensitivity. The influence of HFD, gender, and long-term response of SuMN-THx was subsequently investigated in female HFDr rats fed HFD, male HFDr rats fed RC, and female HFD-sensitive rats fed RC over 1 year, respectively.

RESULTS

SuMN-THx induced obesity and glucose intolerance, elevated plasma leptin and triglycerides, increased hepatic mRNA levels of gluconeogenic, lipogenic, and pro-inflammatory genes, reduced white adipose fatty acid oxidation rate, and altered plasma corticosterone level and hepatic circadian gene expression. Moreover, SuMN-THx increased feeding during the natural resting/fasting period and altered ghrelin feeding response suggesting ghrelin resistance. This MS-inducing effect was enhanced by HFD feeding, similarly observed in male rats and persisted over 1 year.

DISCUSSION/CONCLUSION

SuMN-THx induced long-term, gender-nonspecific, multiple pathophysiological changes leading to MS suggesting SuMN dopaminergic circuits communicating with other brain metabolism and behavior control centers modulate peripheral fuel metabolism.

Hepatic Vagal Afferents Convey Clock-Dependent Signals to Regulate Circadian Food Intake

Circadian desynchrony induced by shiftwork or jetlag is detrimental to metabolic health, but how synchronous/desynchronous signals are transmitted among tissues is unknown. Here we report that liver molecular clock dysfunction is signaled to the brain via the hepatic vagal afferent nerve (HVAN), leading to altered food intake patterns that are corrected by ablation of the HVAN. Hepatic branch vagotomy also prevents food intake disruptions induced by high-fat diet feeding and reduces body weight gain. Our findings reveal a previously unrecognized homeostatic feedback signal that relies on synchrony between the liver and the brain to control circadian food intake patterns. This identifies the hepatic vagus nerve as a therapeutic target for obesity in the setting of chrono-disruption.

One Sentence Summary

The hepatic vagal afferent nerve signals internal circadian desynchrony between the brain and liver to induce maladaptive food intake patterns.

Comprehensive assessment of chrononutrition behaviors among nationally representative adults: Insights from National Health and Nutrition Examination Survey (NHANES) data

BACKGROUND

Aligning the time of food intake, i.e., chrononutrition, with the body's circadian clock can have a significant impact on overall health, particularly cardiometabolic health. However, there is a lack of population-based information on various chrononutrition behaviors in the United States, where the prevalence of obesity is high.

OBJECTIVE

Our primary aim was to characterize chrononutrition behaviors and their 15-year trends among US adults. We also explored the temporal associations between trends in chrononutrition behaviors and trends in obesity.

DESIGN

We utilized data from 8 cycles (2003-2018) of the National Health and Nutrition Examination Survey (NHANES) on 34,470 adults (age >19 years). The clock time of food/beverage consumption was extracted from two 24-h food recalls. The following chrononutrition behaviors were defined: 1) The clock time of the first, last, and midpoint (when 50% of total daily energy was consumed) of food/beverage intake; 2) Eating window (the time elapsed between the first and last intake); 3) Late-night eating (food intake between 21:00-23:59); and 4) Eating frequency. Survey-weighted % or mean ± standard error (SE) was used to demonstrate chrononutrition behaviors and survey-weighted regression models were utilized to evaluate trends in chrononutrition behaviors, BMI, and obesity over a 15-year period.

RESULTS

Thirty five percent of US adults had long eating windows lasting 13 h or more, with 59% of individuals consuming calories after 9 PM. The patterns of food intake among American adults were skewed, with the highest proportion of their daily energy intake (36%) being consumed during dinner meals. Notable differences in chrononutrition behaviors observed among different population subgroups. Young adults and men had longer eating windows with a higher prevalence of late-night eating compared to their age- and sex-counterparts. Black individuals had shorter eating periods due to delayed breakfast, the highest proportion (68%) of late-night eating, and obtained a greater amount of energy intake from snacks compared to other racial/ethnic groups. Over the 15-year span, there were only minor changes in a few aspects of chrononutrition behaviors, including 2% reduction in the time of eating window, while most other meal timing behaviors remained unchanged. Trends in chrononutrition behaviors were disproportionately smaller than the trends in obesity rates.

CONCLUSIONS

US adults persistently consume higher amounts of daily energy intake later in the day. Despite calls for Americans to shift intake to earlier parts of the day, this study shows that there is little change in the overall population over the 15-year period reviewed.

Eating Disorders and Diabetes: Facing the Dual Challenge

Eating disorders and diabetes mellitus are distinct yet closely linked health conditions, presenting distinct challenges in terms of care and management. Eating disorders encompass a spectrum of mental health disorders characterized by abnormal eating behaviors and disruptions in weight regulation. Research indicates that individuals with diabetes might be at an elevated risk of developing eating disorders. The necessity to adhere to specific dietary guidelines, monitor blood sugar levels vigilantly, and manage drug administration can collectively contribute to the emergence of detrimental attitudes toward food and body image. On the other hand, incorrect eating behaviors such as binge eating and purging can disrupt blood sugar control, significantly impacting the development and management of diabetes. This intricate relationship emphasizes the crucial necessity for a comprehensive understanding and specialized care to effectively address the dual challenges faced by individuals dealing with both diabetes and eating disorders. This paper represents the inaugural comprehensive review delving into the intricate connection between eating disorders and diabetes, thereby illuminating previously under-researched areas. The insights gleaned from this review may contribute to developing integrated interventions that aim to improve the overall well-being and quality of life for individuals grappling with the complexities of eating disorders and diabetes.

Peripheral clock disruption and metabolic disease: moving beyond the anatomy to a functional approach

Sleep and circadian disruption are associated with an increased risk of metabolic disease, including obesity and diabetes. Mounting evidence indicates that misaligned and/or non-functional clock proteins in peripheral tissues critically contribute to the presentation of metabolic disease. Many of the foundational studies which led to this conclusion have focused on specific tissues such as the adipose, pancreas, muscle, and liver. While these studies have greatly advanced the field, the use of anatomical markers to manipulate tissue-specific molecular clocks may not be representative of the circadian disruption that occurs within the clinical population. In this manuscript, we argue that investigators can gain a better understanding of the consequences of sleep and circadian disruption by targeting groups of cells with a functional relationship, even if those cells go beyond anatomical boundaries. This approach is especially important when considering metabolic outcomes which rely on endocrine signaling molecules, such as leptin, that have multiple sites of action. Through the review of several studies, as well as our own work, this article reframes peripheral clock disruption from a functional approach. We additionally present new evidence that disruption of the molecular clock within all cells expressing the leptin receptor affects leptin sensitivity in a time-dependent manner. Taken together, this perspective aims to provide new insight into the mechanisms leading to metabolic disease associated with circadian disruption and various sleep disorders.

Emotional Eating and Binge Eating Disorders and Night Eating Syndrome in Polycystic Ovary Syndrome-A Vicious Circle of Disease: A Systematic Review

Obesity is an established risk factor for the development of polycystic ovary syndrome (PCOS), especially phenotype A. PCOS is an important cause of fertility disorders in a large group of women of reproductive age. For many years, effective methods of treating hormonal disorders associated with PCOS have been sought in order to restore ovulation with regular menstrual cycles. Numerous studies support obesity treatment as an effective therapeutic method for many women. A seemingly simple method of treatment may prove to be particularly difficult in this group of women. The reason for this may be the lack of recognition the primary cause of obesity development or the occurrence of a vicious circle of disease. Primary causes of developing obesity may be emotional eating (EE) and eating disorders (EDs), such as binge eating disorder (BED) and its extreme form, addictive eating, as well as night eating syndrome (NES). All of these are caused by impaired function of the reward system. Consequently, these disorders can develop or be exacerbated in women with obesity and PCOS as a result of depression and anxiety related to hirsutism and fertility disturbances. Therefore, for the effective treatment of obesity, it is very important to recognize and treat EE, BED, and NES, including the appropriate selection of pharmacotherapy and psychotherapy. Therefore, the aim of our manuscript is to analyze the available data on the relationships between EE, BED, NES, obesity, and PCOS and their impact on the treatment of obesity in women with PCOS.

An Updated Review of Night Eating Syndrome: An Under-Represented Eating Disorder

PURPOSE OF REVIEW

Night eating syndrome (NES) is an eating disorder that has historically been under-studied. The current review aims to summarize the most up-to-date research on NES to support better awareness.

RECENT FINDINGS

Since NES was recently included as a formal diagnosis, research on the prevalence of NES is ever evolving. Current studies underscore the high comorbidity between NES and other eating disorders, with additional complexities for patient with comorbid eating disorders. Recent findings also support the association between NES and sleep correlates, a relationship that has remained during the COVID-19 pandemic. Emerging research confirms correlates of distress in NES across cultures. There remain mixed findings between NES and BMI. There is also debate around whether age is a risk factor. Bariatric surgery research has focused on the re-emergence of NES post-operatively. Our understanding of the correlates of NES is increasing. However, research on the treatment for NES remains particularly under-studied and requires further attention.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Obesity, cancer risk, and time-restricted eating

Obesity and the associated metabolic syndrome is considered a pandemic whose prevalence is steadily increasing in many countries worldwide. It is a complex, dynamic, and multifactorial disorder that presages the development of several metabolic, cardiovascular, and neurodegenerative diseases, and increases the risk of cancer. In patients with newly diagnosed cancer, obesity worsens prognosis, increasing the risk of recurrence and decreasing survival. The multiple negative effects of obesity on cancer outcomes are substantial, and of great clinical importance. Strategies for weight control have potential utility for both prevention efforts and enhancing cancer outcomes. Presently, time-restricted eating (TRE) is a popular dietary intervention that involves limiting the consumption of calories to a specific window of time without any proscribed caloric restriction or alteration in dietary composition. As such, TRE is a sustainable long-term behavioral modification, when compared to other dietary interventions, and has shown many health benefits in animals and humans. The preliminary data regarding the effects of time-restricted feeding on cancer development and growth in animal models are promising but studies in humans are lacking. Interestingly, several short-term randomized clinical trials of TRE have shown favorable effects to reduce cancer risk factors; however, long-term trials of TRE have yet to investigate reductions in cancer incidence or outcomes in the general population. Few studies have been conducted in cancer populations, but a number are underway to examine the effect of TRE on cancer biology and recurrence. Given the simplicity, feasibility, and favorable metabolic improvements elicited by TRE in obese men and women, TRE may be useful in obese cancer patients and cancer survivors; however, the clinical implementation of TRE in the cancer setting will require greater in-depth investigation.

Behavior, motivational interviewing, eating disorders, and obesity management technologies: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of "Behavior, Motivational Interviewing, Eating Disorders, and Obesity Management Technologies."

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS outlines important components of behavior, motivational interviewing, eating disorders, and obesity management technologies as they relate to pre-obesity and obesity. Topics include eating behavior disorder evaluation, the motivations behind eating and physical activity behaviors (including underlying neurophysiology, eating disorders, environmental factors, and personal prioritization), motivational interviewing techniques, and technologies that may assist with pre-obesity/obesity management.

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on "Behavior, Motivational Interviewing, Eating Disorders, and Obesity Management Technologies" is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of pre-obesity/obesity. Implementation of appropriate clinical practices in these areas may improve the health of patients, especially those with adverse fat mass and adiposopathic metabolic consequences.

Patterns of perceived parenting styles and associations with night eating syndrome symptoms and correlates among Chinese adolescents: a latent profile analysis

PURPOSE

This paper aimed to explore the association between the patterns of perceived parenting styles and adolescents' night eating syndrome symptoms and correlates, including sleep quality, weight status, loss of control over eating, and psychological distress.

METHODS

A sample of 455 Chinese adolescents (54.5% females, aged 12-15 years) were included in the current study. Latent Profile Analysis (LPA) was adopted to examine the patterns of perceived parenting styles. The three-step approach was used to explore the differences in night eating syndrome symptoms and correlates between different profiles.

RESULTS

A four-profile solution was found to fit the data best, and the four profiles were labeled as positive parenting, negative parenting, highly engaged parenting, and lowly engaged parenting. Subsequent analyses showed that adolescents across profiles exhibited significant differences in night eating syndrome symptoms and correlates. Specifically, adolescents in the positive parenting profile generally had the lowest scores in night eating and its correlates, while those in the negative parenting group reported the highest scores in night eating and its correlates.

CONCLUSION

Using a person-centered approach (i.e., LPA), the present study identified four distinct patterns of perceived parenting styles in a sample of Chinese adolescents, with night eating and related symptomatology differing across each profile. Future interventions targeting night eating among adolescents may consider the potential influence from the patterns of perceived parenting styles to have a better intervention outcome.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Night eating, weight, and health behaviors in adults participating in the Daily24 study

BACKGROUND

Night eating syndrome (NES) is associated with adverse health outcomes. This study evaluated the relationship between night eating severity, weight, and health behaviors.

METHODS

Participants (N = 1017; 77.6% female, mean Body Mass Index (BMI) = 30.5, SD = 7.8 kg/m², age = 51.1, SD = 15.0 years) were recruited from three health systems. Participants completed the Night Eating Questionnaire (NEQ) and questionnaires assessing sleep, chronotype, physical activity, diet, weight, and napping.

RESULTS

In the overall sample, higher NEQ scores were associated with higher BMI (p < .001) and consumption of sugar-sweetened beverages (p < .001), as well as lower fruit/vegetable consumption (p = .001). Higher NEQ scores were associated with increased odds of having overweight/obesity (p < .001), eating fast food (p < .001), moderate-vigorous physical activity (p = .005), and smoking (p = .004). Participants who exceeded the screening threshold for NES (n = 48, 4.7%) reported elevated BMI (p = .014), an increased likelihood of overweight/obesity (p = .004), greater sugar-sweetened beverages consumption (p < .001), napping less than twice per week (p = .029), shorter sleep duration (p = .012), and a later chronotype (M = 4:55, SD = 2:45).

CONCLUSION

Night eating severity was associated with obesity and intake of fast food and sugar-sweetened beverages. Interventions to address night eating and associated behaviors may enhance the efficacy of weight management interventions and promote engagement in positive health behaviors.

'In the night kitchen': A scoping review on the night eating syndrome

BACKGROUND

First described in 1955, night eating syndrome refers to an abnormal eating behavior clinically defined by the presence of evening hyperphagia (>25% of daily caloric intake) and/or nocturnal awaking with food ingestion occurring ⩾ 2 times per week.

AIMS

Although the syndrome is frequently comorbid with obesity, metabolic and psychiatric disorders, its etiopathogenesis, diagnosis, assessment and treatment still remain not fully understood.

METHODS

This review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines; PubMed database was searched until 31 October 2020, using the key terms: 'Night Eating Syndrome' AND 'complications' OR 'diagnosis' OR 'drug therapy' OR 'epidemiology' OR 'etiology' OR 'physiology' OR 'physiopathology' OR 'psychology' OR 'therapy'.

RESULTS

From a total of 239 citations, 120 studies assessing night eating syndrome met the inclusion criteria to be included in the review.

CONCLUSION

The inclusion of night eating syndrome into the Diagnostic and Statistical Manual of Mental Disorders-5 'Other Specified Feeding or Eating Disorders' category should drive the attention of clinician and researchers toward this syndrome that is still defined by evolving diagnostic criteria. The correct identification and assessment of NES could facilitate the detection and the diagnosis of this disorder, whose bio-psycho-social roots support its multifactorial nature. The significant rates of comorbid illnesses associated with NES and the overlapping symptoms with other eating disorders require a focused clinical attention. Treatment options for night eating syndrome include both pharmacological (selective serotonin reuptake inhibitors, topiramate and melatonergic drugs) and non-pharmachological approaches; the combination of such strategies within a multidisciplinary approach should be addressed in future, well-sized and long-term studies.

Effects of night eating and binge eating disorders on general health in university students in Lebanon

BACKGROUND

Eating disorders (EDs) have an important impact on both physical and mental wellbeing, especially in a young population. There is a lack in research about EDs in the Middle East, and especially in Lebanon, where the co-occurring obesity is a widespread health problem.

AIM

Our study aims to assess the relation between night eating syndrome (NES) with binge eating disease (BED) and obesity (BMI) on one hand, and between NES and general health on the other hand, in university students.

MATERIALS AND METHODS

An observational cross-sectional study was conducted on 460 university students in Lebanon. Data collection was carried out using an online questionnaire. Socio-demographic and general health characteristics, BMI, Arabic validated General Health Questionnaire (GHQ-12), Arabic validated Binge Eating Scale (BES) and the Night Eating Diagnostic Questionnaire (NEDQ). Statistical analysis was accomplished on SPSS.

RESULTS

Participants having highest income showed highest NEDQ score. Females and participants with a history of eating disorders were more likely to have BED. A significant correlation was also found between having an ED history and negative impact on general health. BMI was correlated with both NEDQ and BES. Having NES was associated with also having BED. Furthermore, those with NES showed higher scores regarding GHQ-12.

CONCLUSION

Relatively high prevalence of NES and BED was noted in university students in Lebanon. This was correlated to a household income, general health, and BMI. The repercussion on both physical and mental morbidities highlights the importance for stepping up of the Lebanese organizational system to perform periodic screening.

A Cross-Sectional Study of Evening Hyperphagia and Nocturnal Ingestion: Core Constituents of Night Eating Syndrome with Different Background Factors

This web-based cross-sectional survey aimed to elucidate the differences between the two core symptoms of night eating syndrome (NES): evening hyperphagia and nocturnal ingestion in the general Japanese population aged 16–79 years. Participants who consumed at least 25% of daily calories after dinner were defined as having evening hyperphagia. Those who consumed food after sleep initiation at least twice a week were determined to have nocturnal ingestion. Of the 8348 participants, 119 (1.5%) were categorized in the evening hyperphagia group, 208 (2.6%) in the nocturnal ingestion group, and 8024 in the non-NES group. Participants with evening hyperphagia and nocturnal ingestion had significantly higher anxiety scores (p < 0.05 and p < 0.001, respectively) and depression (p < 0.001 for both) than those without NES. Multiple logistic regression analysis revealed that evening hyperphagia was significantly and independently associated with higher body mass index, shorter sleep duration, later sleep-wake schedule, and higher insomnia score, while nocturnal ingestion was significantly and independently associated with younger age, smoking habit, living alone, earlier sleep-wake schedule, and higher insomnia score. Sleep duration and sleep-wake schedule characteristics in the two groups were opposite, suggesting differences in the sleep pathophysiology mechanisms.

Chronobiological evaluation and an intervention study on timing of food intake in the treatment of obesity

BACKGROUND

The chronotype of patients who cannot reach their ideal weight despite diet and exercise may play a role in this resistance. In this study, the relationship between BMI and chronobiological preferences was examined and a weight loss programme was applied to refractory obese patients with evening type (ET).

METHOD

The study included 50 obese (BMI ≥ 30 kg/m² ), 50 overweight (BMI = 25-29 kg/m² ) and 50 normal weight (BMI < 25 kg/m² ). The patients were asked to fill out a questionnaire including questions about sociodemographic characteristics, breakfast and night eating habits, as well as the morningness-eveningness quastionnaire (MEQ). In the second stage of the study, awareness interviews were held with ET obese patients in terms of eating time and habits.

RESULTS

A statistically significant difference was observed between the BMI averages and the MEQ scores of ET, intermediate type (IT) and morning type (MT) groups (P = .0001). There was a statistically significant difference between the ET, IT and MT groups in terms of the distribution of late-night eating habits (P = .0001). The habit of skipping breakfast and taking more calories at dinner was found to be high in the ET patients (respectively; P = .021, P < .001). According to the results of the 3-month follow-up and intervention, the ET patients lost an average of 9.07±4.30 kg and a significant decrease was observed in the BMI scores (P < .001).

CONCLUSIONS

The study results support the idea that an individualised weight loss programme according to the patient's chronotype preferences may increase the success rate of obesity treatment. A weight loss programme that includes the timing of food intake and regulation of eating habits in evening-type obese patients can be used in the treatment of obesity.

Effects of late-night eating of easily-or slowly-digestible meals on sleep, hypothalamo-pituitary-adrenal axis, and autonomic nervous system in healthy young males

Aim of the current study was to assess the effects of the digestibility of late-night high calorie meal on sleep and the activities of the hypothalamo-pituitary-adrenal (HPA) and autonomous nervous system (ANS) in healthy young males. For that purpose, effects of an easily digestible meal (starch + sugar-rich meal, SSR, i.e., dessert) or a slowly digestible meal (protein + fat-rich, PFR, i.e. kebab) were investigated in a crossover design in 16 participants (20-26 year old). They did not eat anything after 07:00 PM on Day 0; had an SSR meal on Day 1 and a PFR meal on Day 2 at 10:00 PM. HPA and ANS activities were measured by cortisol awakening response (CAR) and heart rate variability (HRV), respectively. The participants provided salivary samples for CAR; had a 5-min continuous electrocardiogram recording for HRV; and filled in sleep questionnaires. Late-night eating of SSR and PFR diets increased the area under the curve of CAR (p < 0.05) but did not affect HRV parameters (p > 0.05). PFR meal significantly disturbed sleep (p < 0.05). The data suggests that increased activity of HPA, but not ANS, might be involved in pathophysiology of late-night eating and that this might be due to disturbed sleep if slowly-digestible meal is consumed.

Circadian Rhythm Disruption Influenced Hepatic Lipid Metabolism, Gut Microbiota and Promoted Cholesterol Gallstone Formation in Mice

BACKGROUND

Hepatic lipid metabolism regulates biliary composition and influences the formation of cholesterol gallstones. The genes Hmgcr and Cyp7a1, which encode key liver enzymes, are regulated by circadian rhythm-related transcription factors. We aimed to investigate the effect of circadian rhythm disruption on hepatic cholesterol and bile acid metabolism and the incidence of cholesterol stone formation.

METHODS

Adult male C57BL/6J mice were fed either a lithogenic diet (LD) only during the sleep phase (time-restricted lithogenic diet feeding, TRF) or an LD ad libitum (non-time-restricted lithogenic diet feeding, nTRF) for 4 weeks. Food consumption, body mass gain, and the incidence of gallstones were assessed. Circulating metabolic parameters, lipid accumulation in the liver, the circadian expression of hepatic clock and metabolic genes, and the gut microbiota were analyzed.

RESULTS

TRF caused a dysregulation of the circadian rhythm in the mice, characterized by significant differences in the circadian expression patterns of clock-related genes. In TRF mice, the circadian rhythms in the expression of genes involved in bile acid and cholesterol metabolism were disrupted, as was the circadian rhythm of the gut microbiota. These changes were associated with high biliary cholesterol content, which promoted gallstone formation in the TRF mice.

CONCLUSION

Disordered circadian rhythm is associated with abnormal hepatic bile acid and cholesterol metabolism in mice, which promotes gallstone formation.

Depression symptoms and night eating in young adulthood

PURPOSE

We estimated cross-sectional and longitudinal associations between depression symptoms and night eating in young adults.

METHODS

Data were drawn from a longitudinal investigation of students age 12-13 years at inception in 1999-2000, in Montreal, Canada. Depression symptoms were measured with the Depressive Symptoms Scale (DSS) 20 times from age 12 to 17, and with the Major Depression Inventory (MDI) post-high school at ages 20 and 24. Night eating was measured at age 24. The association between depression symptoms and night eating was estimated in multivariable logistic regression models adjusted for sex, age and mother university-educated.

RESULTS

9% of 829 participants (n = 77) reported night eating. In cross-sectional analysis, the adjusted odds ratio (OR) estimate for MDI scores (range 0-50) was 1.04 (1.01, 1.07). In longitudinal analyses, the OR estimates were 1.75 (1.20, 2.55) for DSS scores (range 1-4) and 1.03 (1.002, 1.06) for the MDI.

CONCLUSIONS

Depression symptoms are associated with night eating in young adults cross-sectionally and possibly longitudinally. Treatment of depression symptoms may be important in preventing night eating, a core symptom of the Night Eating Syndrome.

LEVEL OF EVIDENCE

Level III, cohort analytic study.

Prolonged, Controlled Daytime versus Delayed Eating Impacts Weight and Metabolism

A delayed eating schedule is associated with increased risk of obesity and metabolic dysfunction in humans.^1-9 However, there are no prolonged, highly controlled experimental studies testing the effects of meal timing on weight and metabolism in adults with a body mass index (BMI) of 19-27 kg/m².^10-18 Twelve healthy adults (age: 26.3 ± 3.4 years; BMI: 21.9 ± 1.7 kg/m²; 5 females) participated in a randomized crossover study in free-living conditions. Three meals and two snacks with comparable energy and macronutrient contents were provided during two, 8-week, counterbalanced conditions separated by a 2-week washout period: (1) daytime (intake limited to 0800 h-1900 h) and (2) delayed (intake limited to 1200 h-2300 h). Sleep-wake cycles and exercise levels were held constant. Weight, adiposity, energy expenditure, and circadian profiles of hormones and metabolites were assessed during four inpatient visits occurring before and after each condition. Body weight, insulin resistance (homeostatic model assessment of insulin resistance [HOMA-IR]), trunk-to-leg fat ratio, resting energy expenditure, respiratory quotient, and fasting glucose, insulin, total and high-density lipoprotein (dHDL) cholesterol, and adiponectin decreased on the daytime compared to the delayed schedule. These measures, as well as triglycerides, increased on the delayed compared to the daytime schedule (effect size range: d = 0.397-1.019). Circadian phase and amplitude of melatonin, cortisol, ghrelin, leptin, and glucose were not differentially altered by the eating schedules. Overall, an 8-week daytime eating schedule, compared to a delayed eating schedule, promotes weight loss and improvements in energy metabolism and insulin in adults with BMI 19-27 kg/m², underscoring the efficacy and feasibility of daytime eating as a behavioral modification for real-world conditions.

Eating Disorders and Overweight/Obesity in Veterans: Prevalence, Risk Factors, and Treatment Considerations

PURPOSE OF REVIEW

Eating disorders (EDs) and overweight/obesity (OW/OB) have a significant impact on veterans. This review highlights current research on EDs and OW/OB in this population.

RECENT FINDINGS

Prevalence estimates for both EDs and OW/OB among veterans remain consistent with and possibly higher than those in the general population. Both diagnoses share multiple risk factors, including trauma history, and mental health comorbidities. Although weight loss treatments have been fairly well studied among veteran samples, there are no published investigations on psychotherapies for EDs in this population. The Veterans Healthcare Administration is working to train providers in ED treatments. VHA treatments for OW/OB show some benefits and areas for improvement. Areas for future research include structured assessments for EDs and disordered eating behaviors in veterans to clarify prevalence estimates. There is a need for interventions that consider common mechanisms for ED and OW/OB, and there is a need for more research on the associations between different types of trauma and ED/OW/OB in veterans.

Feeding Rhythms and the Circadian Regulation of Metabolism

The molecular circadian clock regulates metabolic processes within the cell, and the alignment of these clocks between tissues is essential for the maintenance of metabolic homeostasis. The possibility of misalignment arises from the differential responsiveness of tissues to the environmental cues that synchronize the clock (zeitgebers). Although light is the dominant environmental cue for the master clock of the suprachiasmatic nucleus, many other tissues are sensitive to feeding and fasting. When rhythms of feeding behavior are altered, for example by shift work or the constant availability of highly palatable foods, strong feedback is sent to the peripheral molecular clocks. Varying degrees of phase shift can cause the systemic misalignment of metabolic processes. Moreover, when there is a misalignment between the endogenous rhythms in physiology and environmental inputs, such as feeding during the inactive phase, the body's ability to maintain homeostasis is impaired. The loss of phase coordination between the organism and environment, as well as internal misalignment between tissues, can produce cardiometabolic disease as a consequence. The aim of this review is to synthesize the work on the mechanisms and metabolic effects of circadian misalignment. The timing of food intake is highlighted as a powerful environmental cue with the potential to destroy or restore the synchrony of circadian rhythms in metabolism.

DSM-5 full syndrome, other specified, and unspecified eating disorders in Australian adolescents: prevalence and clinical significance

BACKGROUND

Little information is available on the prevalence of Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 eating disorders in adolescence, and eating disorders remain unique in the DSM for not systematically including a criterion for clinical significance. This study aimed to provide the first prevalence report of the full suite of DSM-5 eating disorders in adolescence, and to examine the impact of applying a criterion for clinical significance.

METHODS

In total, 5191 (participation rate: 70%) Australian adolescents completed a survey measuring 1-month prevalence of eating disorder symptoms for all criterial, 'other specified' and unspecified eating disorders, as well as health-related quality of life and psychological distress.

RESULTS

The point prevalence of any eating disorder was 22.2% (12.8% in boys, 32.9% in girls), and 'other specified' disorders (11.2%) were more common than full criterial disorders (6.2%). Probable bulimia nervosa and binge eating disorder, but not anorexia nervosa (AN), were more likely to be experienced by older adolescents. Most disorders were associated with an increased odds for being at a higher weight. The prevalence of eating disorders was reduced by 40% (to 13.6%) when a criterion for clinical significance was applied.

CONCLUSIONS

Eating disorders, particularly 'other specified' syndromes, are common in adolescence, and are experienced across age, weight, socioeconomic and migrant status. The merit of adding a criterion for clinical significance to the eating disorders, similar to other DSM-5 disorders, warrants consideration. At the least, screening tools should measure distress and impairment associated with eating disorder symptoms in order to capture adolescents in greatest need for intervention.

Circadian Misalignment of the 24-hour Profile of Endocannabinoid 2-Arachidonoylglycerol (2-AG) in Obese Adults

CONTEXT

The endocannabinoid (eCB) system partly controls hedonic eating, a major cause of obesity. While some studies suggested an overactivation of the eCB system in obesity, peripheral levels of eCBs across the 24-hour cycle have not been characterized in obese individuals despite the fact that in lean adults, levels of the eCB 2-arachidonoylglycerol (2-AG) vary across the day.

OBJECTIVE

We sought to examine 24-hour profiles of serum concentrations of 2-AG in healthy obese and nonobese adults, under well-controlled laboratory conditions. We also simultaneously assessed 24-hour profiles of 2-oleoylglycerol (2-OG), leptin, and cortisol in each participant.

DESIGN

With fixed light-dark and sleep-wake cycles, blood sampling was performed over an entire 24-hour period, including identical meals at 0900, 1400, and 1900.

PARTICIPANTS

Twelve obese (8 women, mean body mass index [BMI]: 39.1 kg/m2) and 15 nonobese (6 women; mean BMI: 23.6 kg/m2) healthy adults were studied.

RESULTS

We observed a 24-hour variation of 2-AG levels in obese individuals but, relative to nonobese adults, the amplitude was dampened and the timings of the nadir and peak were delayed by 4 to 5 hours. The profile of 2-OG was similarly misaligned. In contrast, when expressed relative to the 24-hour mean level, the 24-hour rhythm of cortisol and leptin were similar in obese and nonobese participants.

CONCLUSIONS

Obesity appears to be associated with a dampening and delay of the 24-hour variation of eCB activity relative to the central circadian signal as well as to the daily leptin rhythm. This misalignment may play a role in the pathophysiology of obesity.

Time-of-Day-Dependent Physiological Responses to Meal and Exercise

The mammalian circadian clock drives the temporal coordination in cellular homeostasis and it leads the day-night fluctuation of physiological functions, such as sleep/wake cycle, hormonal secretion, and body temperature. The mammalian circadian clock system in the body is classified hierarchically into two classes, the central clock in the suprachiasmatic nucleus (SCN) of the hypothalamus and the peripheral clocks in peripheral tissues such as the intestine and liver, as well as other brain areas outside the SCN. The circadian rhythm of various tissue-specific functions is mainly controlled by each peripheral clock and partially by the central clock as well. The digestive, absorptive, and metabolic capacities of nutrients also show the day-night variations in several peripheral tissues such as small intestine and liver. It is therefore indicated that the bioavailability or metabolic capacity of nutrients depends on the time of day. In fact, the postprandial response of blood triacylglycerol to a specific diet and glucose tolerance exhibit clear time-of-day effects. Meal frequency and distribution within a day are highly related to metabolic functions, and optimal time-restricted feeding has the potential to prevent several metabolic dysfunctions. In this review, we summarize the time-of-day-dependent postprandial response of macronutrients to each meal and the involvement of circadian clock system in the time-of-day effect. Furthermore, the chronic beneficial and adverse effects of meal time and eating pattern on metabolism and its related diseases are discussed. Finally, we discuss the timing-dependent effects of exercise on the day-night variation of exercise performance and therapeutic potential of time-controlled-exercise for promoting general health.

The association between sleep chronotype and obesity among black and white participants of the Bogalusa Heart Study

Research indicates that sleep duration and quality are inter-related factors that contribute to obesity, but few studies have focused on sleep chronotype, representing an individual's circadian proclivity, nor assessed these factors in racially diverse middle-aged samples. We examined the associations between chronotype and obesity among black and white men and women participating in the Bogalusa Heart Study (BHS).Body mass index (BMI) and sleep data were available for 1,197 middle-aged men and women (mean age 48.2 ± 5.3 years) who participated in the BHS 2013-2016. Based on the reduced Morningness-Eveningness Questionnaire's cutoff values for chronotypes, we combined 'definitely morning' and 'moderately morning' types into 'morning' type, 'definitely evening' and 'moderately evening' types into 'evening' type and kept those who were "neither" type in a separate group. We used 'morning' type as the referent group. Obesity was defined as a BMI ≥ 30. Multivariable logistic regression models were used to examine associations adjusting for sex, age, education, smoking, alcohol use and drug use, depression, shift work, physical activity and sleep duration.Evening chronotype, reported by 11.1% of participants, was associated with obesity after multi-variable adjustment, including shift work, physical activity and sleep duration (OR 1.67, 95% CI: 1.08-2.56). However, once stratified by race (black/white), this association was found only among white participants (OR = 1.91, 95% CI = 1.12-3.25) after full adjustment.In our biracial, community-based population, evening chronotype was independently associated with obesity, specifically among white participants. Further research is needed to identify behavioral, endocrine, nutritional and genetic pathways which underlie these associations.

Night eating syndrome: a psychiatric disease, a sleep disorder, a delayed circadian eating rhythm, and/or a metabolic condition?

Introduction: Night Eating Syndrome (NES) refers to an abnormal eating behavior which presents as evening hyperphagia consuming >25% calorie intake and/or nocturnal awaking with food ingestion which occurs ≥2 times per week. Although the syndrome has been described more than seven decades ago, the literature has been growing slowly on its etiology, diagnosis, and treatment. Areas covered: The proposed treatment options for NES are all at a case-study level. Moreover, our understanding of its etiology, comorbidities, and diagnosis is still premature. We performed a literature review in Medline/PubMed to identify all the studies proposing a management plan for NES and summarized all the existing data on its diagnosis and treatment. Expert opinion: To date, none of the proposed treatment options for NES have been promising and long-term data on its efficacy is lacking. The slow growth of evidence on this debilitating but underreported condition may be due to unawareness among clinicians, under-reporting by patients, and unrecognized diagnostic criteria. Objective screening of symptoms during office visits especially for patients at a high-risk for NES will identify more patients suffering from the syndrome.

Dysfunctional eating in type 2 diabetes mellitus: A multicenter Italian study of socio-demographic and clinical associations

BACKGROUND AND AIMS

Dysfunctional eating might impact on the management and metabolic control of type 2 diabetes (T2DM), modifying adherence to healthy diet and food choices.

METHODS AND RESULTS

In a multicenter study, we assessed the prevalence of dysfunctional eating in 895 adult outpatients with T2DM (51% males, median age 67, median BMI 30.3 kg/m²). Socio-demographic and clinical characteristics were recorded; dysfunctional eating was tested by validated questionnaires (Eating Attitude Test-EAT-26, Binge Eating Scale-BES; Night Eating Questionnaire-NEQ); food intake and adherence to Mediterranean diet were also measured (in-house developed questionnaire and Mediterranean Diet Score-MDS). Obesity was present in 52% of cases (10% obesity class III), with higher rates in women; 22% had HbA1c ≥ 8%. The EAT-26 was positive in 19.6% of women vs. 10.2% of men; BES scores outside the normal range were recorded in 9.4% of women and 4.4% of men, with 3.0% and 1.5% suggestive of binge eating disorder, respectively. Night eating (NEQ) was only present in 3.2% of women and 0.4% of men. Critical EAT and BES values were associated with higher BMI, and all NEQ + ve cases, but one, were clustered among BES + ve individuals. Calorie intake increased with BES, NEQ, and BMI, and decreased with age and with higher adherence to Mediterranean diet. In multivariable logistic regression analysis, female sex, and younger age were associated with increase risk of dysfunctional eating.

CONCLUSION

Dysfunctional eating is present across the whole spectrum of T2DM and significantly impacts on adherence to dietary restriction and food choices.

Relationship between Night Eating Syndrome and Self-esteem: A Cross-sectional Population-based Study in Karachi, Pakistan

Background

The amount of literature shedding light upon eating disorders in developing countries, such as Pakistan, is scarce. This is partially because talking about such matters is considered taboo in the general population. Night Eating Syndrome’s (NES) link with depression and obesity has been established; however, presently, no study has been conducted which solely focuses on NES’s correlation with self-esteem. Therefore, to bridge this knowledge gap, we conducted this study to assess the prevalence of NES in Karachi and its association with self-esteem.

Methods

We conducted a cross-sectional study in August 2018 using convenience sampling in 395 individuals, out of which 197 belonged to the age group 18-24 and 198 to 25-30. The participants were interviewed for their gender, body mass index (BMI), and their level of education. The participants were asked to complete a structured, standardized questionnaire assessment, which comprised of questions from the Night Eating Questionnaire (NEQ) and Rosenberg Self-Esteem scale (RSE). The eating habits of the participants and the level of self-esteem were assessed using four- and five-point Likert scales. Kruskal-Wallis and chi-square tests were used as the primary statistical tests.

Results

Out of the 395 respondents, more than half of the respondents were females (n = 235/395, 59.5%). About one-fourth (n = 92/395, 23.3%) of the participants had a BMI of greater than 25.0 kg/m². More than one-third of the underweight (n = 20/55, 36.4%) and overweight population (n = 33/92, 35.9%) had low self-esteem, while more than one-fourth (n = 25/92, 27.2%) of the overweight participants fulfilled the criteria of NES. The final outcomes showed that 14.4% of the participants had NES, and 4.6% of the participants had low self-esteem.

Conclusion

Our results pointed out to a significant relationship between NES and self-esteem. Furthermore, NES and self-esteem also had a significant association with age, gender, and BMI. Additionally, awareness regarding eating and mental disorders should be done in countries like Pakistan, where talking in regard to such matters is considered taboo. Given the various factors that further strengthen the positive relationship between NES and low self-esteem, these factors can be the targets on which the treatment can be focused.

A Review of the Relationship between Night Eating Syndrome and Body Mass Index

PURPOSE OF THE REVIEW

To review literature on night eating syndrome (NES) and body mass index (BMI, kg/m²) published in the last 5 years.

RECENT FINDINGS

Since December, 2013, 11 studies examined the association between NES and BMI. Five of these studies reported a positive relationship, five showed no relationship, and one produced mixed findings. Emotional eating and age were moderators. Twelve studies examined whether there was a difference in BMI between those with and without NES with only five of these finding differences. A primary weakness of the recent literature base is that it is almost entirely cross-sectional. Recent findings regarding the relationship between NES and BMI are mixed. Future research should examine the relationship between these variables longitudinally and continue to examine moderating variables that explain why some individuals manifest excess weight with NES and others do not.

Night-time eating and body weight status among US adults, 2007-2016

BACKGROUND

The present study assessed the relationship between night-time eating and body weight status among US adults, using in-person 24-h dietary recall data from a nationally representative survey.

METHODS

Individual-level data (n = 23 003) came from the 2007-2016 National Health and Nutrition Examination Survey (NHANES) (five waves). Multivariate linear and logistic regressions were performed to estimate the effect of energy, sugar, fat and saturated fat intake during night-time on body mass index (BMI), obesity (BMI ≥30 kg m^-2 ), waist circumference (WC) and abdominal obesity (WC ≥88 cm in women; WC ≥102 cm in men), adjusting for daily total energy intake, physical activity, sleeping and other individual characteristics.

RESULTS

Approximately 36.5% and 56.7% of the NHANES adult participants had obesity and abdominal obesity, respectively. The proportion of energy, total fat, saturated fat and total sugar intake within the time window of 00.00 h to 05.59 h and 22.00 h to 23.59 h averaged 5.7%, 5.3%, 5.7% and 6.8%, respectively. Energy intake within the time window was not found to be associated with BMI, WC, obesity or abdominal obesity in the regression analyses. Sensitivity analyses applying alternative time windows to capture night-time eating found night-time intakes of energy, total fat, saturated fat and total sugar not to be associated BMI, WC, obesity or abdominal obesity.

CONCLUSIONS

Night-time eating was not found to be associated with body weight status in a US nationally representative adult sample. Restricting night-time food consumption alone without an overall reduction in daily caloric intake may not prevent obesity. The findings of the present study warrant replication in a future experimental study with habitual dietary behaviour measures.

Timing and Duration of Sleep in Hospitalized Children: An Observational Study

BACKGROUND AND OBJECTIVES

Sleep during hospitalization is important, but data on children's sleep quality during hospitalization are lacking. We sought to document sleep duration and awakenings in hospitalized children and explore associations between sleep and chronic care complexity, home sleep quality, and late-night food consumption.

METHODS

Children aged 2 to 17 years admitted to a hospitalist service for at least 24 hours were approached for participation. Children were video recorded from 20:00 to 08:00. Paired investigators reviewed recordings and extracted data. Investigators blinded to sleep data separately extracted clinical and demographic information. Analyses included Spearman correlations and linear and generalized linear regression models with t and Wald χ² tests.

RESULTS

The mean time subjects (n = 57) initiated sleep was 22:35 (range: 20:00-02:47), with a mean sleep duration of 475 minutes (89-719 minutes). Subjects awakened 2.2 times (0-7 times, SD: 1.9) per night, on average, with the average total time awake during those awakenings of 55.7 minutes (2-352 minutes, SD: 75 minutes). In multivariate analysis, children with private insurance had longer sleep duration. Additionally, subjects who ate a snack after 21:00 went to sleep much later (odds ratio: 9.5; confidence interval: 2.6 to 34.9) and had 64 minutes less total sleep time and spent less time in bed than patients who did not eat late (P = .007).

CONCLUSIONS

Hospitalized children sleep less than recommended and experience frequent awakenings. Some demographic variables are related to sleep. Many hospitalized children also consume food at night, which is associated with later bedtime and less sleep. Future efforts to improve sleep in hospitalized children are needed.

Meal Timing, Aging, and Metabolic Health

A growing body of evidence suggests that meal timing is an important factor for metabolic regulation and that the circadian clock tightly interacts with metabolic functions. The proper functioning of the circadian clock is critical for maintaining metabolic health. Therefore, chrononutrition, a novel discipline which investigates the relation between circadian rhythms, nutrition, and metabolism, has attracted increasing attention in recent years. Circadian rhythms are strongly affected by obesity, type 2 diabetes, and other dietary-induced metabolic diseases. With increasing age, the circadian system also undergoes significant changes which contribute to the dysregulation of metabolic rhythms. Metabolic diseases are a major health concern, particularly in light of a growing aging population, and effective approaches for their prevention and treatment are urgently needed. Recently, animal studies have impressively shown beneficial effects of several dietary patterns (e.g., caloric restriction or time-restricted feeding) on circadian rhythms and metabolic outcomes upon nutritional challenges. Whether these dietary patterns show the same beneficial effects in humans is, however, less well studied. As indicated by recent studies, dietary approaches might represent a promising, attractive, and easy-to-adapt strategy for the prevention and therapy of circadian and metabolic disturbances in humans of different age.

Hours of work and health in Japan

PURPOSE

This article aimed to examine the causal relationships of hours of work with health behaviors and health outcomes.

METHOD

The data were derived from Japan Household Panel Survey/Keio Household Panel Survey. In total, data from 2677 men and 2170 women were analyzed to show the effects of hours of work on body mass index, smoking, and sleeping hours. To deal with the potential endogeneity of decisions about hours of work, the instrumental variable approach was used.

RESULTS

Hours of work had a negative impact on hours of sleep among men (coefficient [coef.], -0.371; 95% confidence interval [CI], -0.519 to -0.223). Longer hours of work also increased the probability of men being obese (coef., 1.108; 95% CI, 0.234-1.981) and the number of cigarettes they smoked each day (coef., 1.007; 95% CI, 0.037-1.978). For women, longer hours of work increased the probability of being obese (coef., 0.029; 95% CI, 0.009-0.050) and decreased the hours of sleep (coef., -0.416; 95% CI, -0.618 to -0.214).

CONCLUSIONS

This article suggests that the health consequences of long hours of work include health behaviors and health outcomes that can lead to higher risks of morbidity and mortality.

Association of night eating habits with metabolic syndrome and its components: a longitudinal study

Background

Night time eating is a risk factor for metabolic syndrome and obesity. The aim of this study was to investigate whether dinner immediately before bed, snacks after dinner, or combinations of both were associated with metabolic syndrome and its components in a large Japanese cohort.

Methods

We enrolled 8153 adults aged 40–54 years who participated in specific medical checkups in an Okayama facility from 2009 to 2010 and from 2013 to 2014. Age-adjusted and multivariable-adjusted odds ratios of metabolic syndrome and its components in participants with both night eating habits for an average of 3.9 years were evaluated. The relative excess risk due to interaction (RERI) was utilized to determine the supra-additive interaction of both eating habits on metabolic syndrome and its components.

Results

The multivariable-adjusted odds ratio for obesity for those with both eating habits compared to those with neither habit was 2.11 (95% confidence interval [CI], 1.42–3.15) for men and 3.02 (95%CI, 1.72–5.29) for women. Both habits had a supra-additive interaction effect on obesity development in women (RERI, 1.67; RERI%, 85.0; p = 0.058), although this result was not significant. In women, there was an association between eating habits at night and metabolic syndrome, but in men it was unrelated. Both night eating habits were associated with dyslipidemia in men and women.

Conclusions

These findings suggest the need for intervention and awareness among individuals with night eating habits to mitigate further complications.

Role of the Circadian Clock in the Metabolic Syndrome and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized nations and is strongly associated with the metabolic syndrome. The prevalence of NAFLD continues to rise along with the epidemic of the metabolic syndrome. Metabolic homeostasis is linked to the circadian clock (rhythm), with multiple signaling pathways in organs regulated by circadian clock genes, and recent studies of circadian clock gene functions suggest that disruption of the circadian rhythm is associated with significant morbidity and mortality, including the metabolic syndrome. In the industrialized world, various human behaviors and activities such as work and eating patterns, jet lag, and sleep deprivation interfere with the circadian rhythm, leading to perturbations in metabolism and development of the metabolic syndrome. In this review, we discuss how disruption of the circadian rhythm is associated with various metabolic conditions that comprise the metabolic syndrome and NAFLD.

Hypothalamic Dysfunction in Obesity and Metabolic Disorders

The hypothalamus is the brain region responsible for the maintenance of energetic homeostasis. The regulation of this process arises from the ability of the hypothalamus to orchestrate complex physiological responses such as food intake and energy expenditure, circadian rhythm, stress response, and fertility. Metabolic alterations such as obesity can compromise these hypothalamic regulatory functions. Alterations in circadian rhythm, stress response, and fertility further contribute to aggravate the metabolic dysfunction of obesity and contribute to the development of chronic disorders such as depression and infertility.At cellular level, obesity caused by overnutrition can damage the hypothalamus promoting inflammation and impairing hypothalamic neurogenesis. Furthermore, hypothalamic neurons suffer apoptosis and impairment in synaptic plasticity that can compromise the proper functioning of the hypothalamus. Several factors contribute to these phenomena such as ER stress, oxidative stress, and impairments in autophagy. All these observations occur at the same time and it is still difficult to discern whether inflammatory processes are the main drivers of these cellular dysfunctions or if the hypothalamic hormone resistance (insulin, leptin, and ghrelin) can be pinpointed as the source of several of these events.Understanding the mechanisms that underlie the pathophysiology of obesity in the hypothalamus is crucial for the development of strategies that can prevent or attenuate the deleterious effects of obesity.

Short-term time-restricted feeding during the resting phase is sufficient to induce leptin resistance that contributes to development of obesity and metabolic disorders in mice

Feeding at unusual times of the day is thought to be associated with obesity and metabolic disorders in both experimental animals and humans. We previously reported that time-imposed feeding during the sleep phase (daytime feeding, DF) induces obesity and metabolic disorders compared with mice fed only during the active phase (nighttime feeding, NF). The present study aimed to determine whether leptin resistance is caused by DF, and whether it is involved in the underlying mechanisms of DF-induced obesity in mice, since leptin plays an essential role in regulating energy expenditure and adiposity in addition to food intake. We compared leptin sensitivity by evaluating the effects of exogenous injected leptin on food intake and body weight in wild-type C57BL/6J mice under NF and DF. The mice were fed with a high-fat high-sucrose diet throughout the study. To determine whether leptin resistance is a cause or a result of DF-induced obesity with metabolic disorders, we restricted the feeding times of leptin resistant db/db mice. We also examined leptin sensitivity in leptin deficient ob/ob mice under NF and DF to elucidate the underlying mechanisms of DF-induced leptin resistance. C57BL/6J mice under DF gained more weight and adiposity compared with mice under NF, and developed hyperleptinemia and hypothermia. We found that six days of DF abolished exogenous leptin-induced hypophagia and reduction in body weight in mice. We also found that the leptin injection significantly suppressed the mRNA expression of lipogenic genes in the liver of NF, but not in DF mice, suggesting that short-term DF was sufficient to induce metabolic leptin resistance. The DF-induced increases in body weight gain, food efficiency, adipose tissue mass, lipogenic gene expression in metabolic tissues, and hepatic lipid accumulation were abolished in db/db mice, suggesting that the leptin resistance is a cause of DF-induced metabolic disorders. DF resulted in deep hypothermia in db/db, as well as in wild-type mice, suggesting that a decrease in energy expenditure was not the main cause of DF-induced obesity. Exogenous leptin reduced the body weight of ob/ob mice under both NF and DF, and the effect was significantly higher in DF- than in NF-ob/ob mice. Therefore, the development of DF-induced leptin resistance requires endogenous leptin, and central leptin sensitivity fluctuates in a circadian manner. The present findings suggest that leptin resistance is responsible for DF-induced obesity and metabolic disorders, and that the circadian fluctuation of central leptin sensitivity might be involved in leptin resistance induced by DF, although further studies are needed to elucidate the mechanisms of metabolic disorders that depend on the time of feeding. Abbreviations: AMPK, adenosine monophosphate-activated protein kinase; ANOVA, analysis of variance; DF, daytime feeding; FFA, free fatty acid; HOMA-IR, homeostasis model assessment of insulin resistance; NEAT, non-exercise activity thermogenesis; NF, nighttime feeding; PI3, phosphatidylinositol 3; RF, restricted feeding; RW, running-wheel; SCN, suprachiasmatic nucleus; SEM, standard error of the mean; STAT3, signal transducer and activator of transcription 3; T-Cho, total cholesterol; TG, triglyceride; WAT, white adipose tissues.

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.

Night eating in bipolar disorder

OBJECTIVE

Night eating syndrome (NES) involves reduced feeding during the day and evening hyperphagia sometimes accompanied by frequent nocturnal awakenings with conscious episodes of compulsive ingestion of food. Previously, NES has not been evaluated in bipolar disorder (BD). The objective of this study was to identify NES in euthymic BD patients.

PATIENTS/METHODS

Eighty BD patients and 40 controls were examined using the Night Eating Questionnaire, Hamilton Rating Scale for Depression and Anxiety, Young Mania Rating Scale, Functioning Assessment Short-Test and International Physical Activity Questionnaire. Sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness Scale), severity of insomnia (Insomnia Severity Index) and morning-evening preference (Morningness-Eveningness Questionnaire) were also evaluated.

RESULTS

BD patients presented NES in 8.8% while the controls showed no NES. Patients with and without NES were not different with respect to gender, disease duration, smoking, heavy drinking, body mass index, waist-to-hip ratio and neck circumference. BD patients with NES scored higher for functioning as well as for the following specific components: occupational functioning, financial issues, interpersonal relationships and leisure time. They also had more anxiety, higher insomnia severity and worse sleep quality. Furthermore, BD patients with NES were more evening type.

CONCLUSION

NES occurs more frequently in BD patients than in controls. BD patients with NES present more disease-related manifestations such as more anxiety, poorer functioning and worse sleep parameters. Patients with NES were more evening type. We speculate whether changing circadian preference in these patients can reduce NES.