Can body temperature dysregulation explain the co-occurrence between overweight/obesity, sleep impairment, late-night eating, and a sedentary lifestyle?

Maternal melatonin levels and temporal dietary intake: results from MY-CARE cohort study

Chrononutrition emerges as a novel approach to promote circadian alignment and metabolic health by means of time-of-the-day dietary intake. However, the relationship between maternal circadian rhythm and temporal dietary intake during pregnancy remains understudied. This study aimed to determine the change in melatonin levels in pregnant women across gestation and its association with temporal energy and macronutrient intake. This was a prospective cohort involving 70 healthy primigravidas. During the second and third trimesters, pregnant women provided salivary samples collected at 9:00, 15:00, 21:00, and 3:00 h over a 24 h day for melatonin assay. Data on chrononutrition characteristics were collected using a 3-day food record. Parameters derived from melatonin measurements including mean, amplitude, maximal level, area under the curve with respect to increase (AUC_I), and area under the curve with respect to ground (AUC_G) were computed. A rhythmic melatonin secretion over the day that remained stable across trimesters was observed among the pregnant women. There was no significant elevation in salivary melatonin levels as pregnancy advanced. In the second trimester, higher energy intake during 12:00-15:59 h and 19:00-06:59 h predicted a steeper melatonin AUC_I (β=-0.32, p = 0.034) and higher AUC_G (β = 0.26, p = 0.042), respectively. Macronutrient intake within 12:00-15:59 h was negatively associated with mean melatonin (Fat: β=-0.28, p = 0.041) and AUC_G (Carbohydrate: β=-0.37, p = 0.003; Protein: β=-0.27, p = 0.036; Fat: β=-0.32, p = 0.014). As pregnant women progressed from the second to the third trimester, a flatter AUC_I was associated with a reduced carbohydrate intake during 12:00-15:59 h (β=-0.40, p = 0.026). No significant association was detected during the third trimester. Our findings show that higher energy and macronutrient intakes particularly during 12:00-15:59 h and 19:00-06:59 h are associated with the disparities in maternal melatonin levels. Findings suggest the potential of time-based dietary approaches to entrain circadian rhythm in pregnant women.

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.

Eating habits are associated with subjective sleep quality outcomes among university students: findings of a cross-sectional study

PURPOSE

This study investigated the relationships between eating habits and sleep quality among university students.

METHODS

In a cross-sectional study, university students completed a self-report questionnaire to assess eating habits and meal timing. We assessed subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and examined the associations between eating habits and overall sleep quality and its components.

RESULTS

Four hundred ninety-eight students participated in the study. Students who used to skip breakfast, ate late-night snacks, and replaced meals with snacks were at 1.20 times, 1.24 times, and 1.25 times higher likelihood of having poor overall sleep quality, respectively. Multiple logistic regression analysis showed that skipping breakfast (r =  - 0.111, P = 0.007), late-night snacks (r =  - 0.109, P = 0.007), replacing meals with snacks (r =  - 0.126, P = 0.002), and irregular mealtimes (r =  - 0.094, P = 0.018) were the best correlates with poor sleep quality. After adjustment to demographic variables, replacing meals with snacks followed by skipping breakfast were the best independent associations with poor sleep quality by the PSQI.

CONCLUSIONS

Eating habits and meal timing were significantly associated with sleep quality. We speculate that healthy eating habits may lead to improved sleep quality and sleep components among university students.

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.

The efficacy of add-on ramelteon and subsequent dose reduction in benzodiazepine derivatives/Z-drugs for the treatment of sleep-related eating disorder and night eating syndrome: a retrospective analysis of consecutive patients

STUDY OBJECTIVES

The objective of this study was to determine the efficacy of ramelteon in treating abnormal eating behavior in patients with sleep-related eating disorder and/or night eating syndrome.

METHODS

We retrospectively reviewed the medical records of patients with sleep-related eating disorder/night eating syndrome at the Yoyogi Sleep Disorder Center from November 2013 to November 2018. We categorized patients as ramelteon treatment responders when the frequency of nighttime eating per week decreased to less than half of that before treatment.

RESULTS

Forty-nine patients were included in the analysis. The mean frequency of eating behavior (per week) (standard deviation) at baseline and post-ramelteon treatment was significantly different, at 5.3 (2.2) and 3.2 (3.0), respectively (P < .001). Twenty-one patients (42.9%) were classified as responders. Adverse events, all of which were mild daytime somnolence, were observed in 5 patients. There were significantly more individuals using benzodiazepine derivatives and Z-drugs before treatment and those with coexisting delayed sleep-wake phase disorder in the responder group than in the nonresponder group (P < .001 and P < .05, respectively). The mean benzodiazepine derivatives and Z-drugs dose significantly decreased from baseline to post-ramelteon treatment within the responder group (P < .05). This trend was not observed in the nonresponder group. Meanwhile, the sleep midpoint of patients with sleep-related eating disorder/night eating syndrome and delayed sleep-wake phase disorder did not significantly change after treatment.

CONCLUSIONS

Our results indicate that ramelteon is a candidate treatment for sleep-related eating disorder/night eating syndrome. The effects of ramelteon might have occurred primarily through the reduction in benzodiazepine derivatives and Z-drugs rather than through the improvement in sleep-wake rhythm dysregulation.

Exploring Therapeutic Targets to Reverse or Prevent the Transition from Metabolically Healthy to Unhealthy Obesity

The prevalence of obesity and obesity-related metabolic comorbidities are rapidly increasing worldwide, placing a huge economic burden on health systems. Excessive nutrient supply combined with reduced physical exercise results in positive energy balance that promotes adipose tissue expansion. However, the metabolic response and pattern of fat accumulation is variable, depending on the individual’s genetic and acquired susceptibility factors. Some develop metabolically healthy obesity (MHO) and are resistant to obesity-associated metabolic diseases for some time, whereas others readily develop metabolically unhealthy obesity (MUO). An unhealthy response to excess fat accumulation could be due to susceptibility intrinsic factors (e.g., increased likelihood of dedifferentiation and/or inflammation), or by pathogenic drivers extrinsic to the adipose tissue (e.g., hyperinsulinemia), or a combination of both. This review outlines the major transcriptional factors and genes associated with adipogenesis and regulation of adipose tissue homeostasis and describes which of these are disrupted in MUO compared to MHO individuals. It also examines the potential role of pathogenic insulin hypersecretion as an extrinsic factor capable of driving the changes in adipose tissue which cause transition from MHO to MUO. On this basis, therapeutic approaches currently available and emerging to prevent and reverse the transition from MHO to MUO transition are reviewed.

Unhealthy eating habits around sleep and sleep duration: To eat or fast?

Traditionally, breakfast skipping (BS), and recently late-night dinner eating (LNDE), have attracted attention in public health because they can predispose to cardiometabolic conditions such as obesity and type 2 diabetes. Intriguingly, it has become evident that short duration of sleep elicits similar health risks. As LNDE, BS, and short sleep can be closely related and can aggravate each other, these three should not be considered separately. In this context, LNDE (or its equivalents, snacking or heavy alcohol consumption after dinner) and BS may be representative unhealthy eating habits around sleep (UEHAS). While it is important to take energy in the early morning for physical and intellectual activities, attaining a fasting state is essential for metabolic homeostasis. Our previous UEHAS studies have shown that BS without LNDE, i.e., BS alone, is not associated with obesity and diabetes, suggesting the possibility that BS or taking a very low energy breakfast, which could yield fasting for a while, may prevent obesity and diabetes in people with inevitable LNDE. Further studies considering UEHAS and short sleep simultaneously are needed to elucidate the effects of these unhealthy lifestyles on cardiometabolic diseases.

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.