Night eating syndrome is associated with depression, low self-esteem, reduced daytime hunger, and less weight loss in obese outpatients

OBJECTIVE: The objective of this study was to assess the relationship between the night eating syndrome (NES), measures of depression and self-esteem, test meal intake, and weight loss in obese participants. RESEARCH METHODS AND PROCEDURES: The study included 76 overweight (body mass index = 36.7 +/- 6.5 SD) outpatients (53 women and 23 men; aged 43.5 +/- 9.5 years) entering a weight loss program. They completed a Night Eating Questionnaire, the Zung Depression Inventory, and the Rosenberg Self-Esteem SCALE: Based on criteria by Stunkard et al. (Stunkard A, Berkowitz R, Wadden T, Tanrikut C, Reiss E, Young L. Binge eating disorder and the night eating syndrome. Int J Obes Relat Metab DISORD: 1996;20:1-6), participants had NES if they reported: (1) skipping breakfast > or =4 d/wk, interpreted as morning anorexia; (2) consuming more than 50% of total daily calories after 7 PM; and (3) difficulty falling asleep or staying asleep > or =4 d/wk. Eleven (14%) participants met the criteria for NES. After an 8-hour fast, all participants ingested a nutritionally complete liquid meal through a straw from a large opaque cooler until extremely full. They also completed ratings of hunger and fullness before and after this meal. RESULTS: Night eaters had higher depression (p = 0.04), lower self-esteem (p = 0.003), and less hunger (p = 0.005), and a trend for more fullness (p = 0.06) before the daytime test meal than the others. However, there were no significant differences in test-meal intake between groups. Nevertheless, test-meal intake was greater later in the day only for the night eaters (p = 0.01). Over a 1-month period, the night eaters lost less weight (4.4 +/- 3.2 kg) than the others (7.3 +/- 3.2 kg; p = 0.04), after controlling for body mass index. DISCUSSION: NES is a syndrome with distinct psychopathology and increased food intake later in the day, both of which may contribute to poorer weight loss outcome. NES criteria need to be better quantified and NES deserves consideration as a diagnostic eating disorder.     

Disordered eating and food cravings among urban obese African American women

OBJECTIVE: The prevalence of night eating syndrome (NES), binge eating disorder (BED), and bulimia nervosa (BN) and the general experience of food cravings were examined in 88 obese urban African American women. METHOD: Participants were administered The Questionnaire on Eating and Weight Patterns-R, the Night Eating Syndrome Questionnaire, and the State and Trait Food Cravings Questionnaire, Trait version (FCQ-T). RESULTS: Twenty-eight percent reported symptoms of eating disorders (18.9% NES, 6.4% recurrent binge eating, 2.2% both NES and recurrent binge eating). Those reporting disordered eating had significantly higher total FCQ-T scores than those not reporting disordered eating. Persons endorsing recurrent binge eating had the highest mean score, followed by those reporting NES. Those who identified themselves as binge eaters and night eaters were not significantly different from each other, but both groups were significantly different than the no eating disorder symptoms group on various subscales of the FCQ-T. DISCUSSION: Obese African American women report significant levels of NES and binge eating which may contribute to the development and/ or maintenance of obesity.     

A descriptive study of non-obese persons with night eating syndrome and a weight-matched comparison group

The purpose of this study was to characterize the Night Eating Syndrome (NES) and its correlates among non-obese persons with NES, and to compare them to non-obese healthy controls. Nineteen non-obese persons with NES were compared to 22 non-obese controls on seven-day, 24-hour prospective food and sleep diaries, the Eating Disorder Examination and the Structured Clinical Interview for DSM-IV Diagnoses interviews, and measures of disordered eating attitudes and behavior, mood, sleep, stress, and quality of life. Compared to controls, persons with NES reported significantly different circadian distribution of food intake, greater depressed mood, sleep disturbance, disordered eating and body image concerns, perceived stress, decreased quality of life, and more frequent Axis I comorbidity, specifically anxiety, mood, and substance use disorders. These findings are the first to describe the clinical significance of night eating syndrome among non-obese individuals in comparison to a non-obese control group, and they suggest that NES has negative health implications beyond that associated with obesity.     

The night eating syndrome: a progress report

The night eating syndrome (NES) is an eating disorder marked by a delay in the circadian pattern of eating that disrupts sleep. Studies have shown that those with NES eat a significant proportion of their calories after their evening meal and wake up during the night to eat. However, the timing of the sleep cycles are phase appropriate, with similar bedtimes and morning wake up times as control subjects, suggesting that the delayed eating rhythm may secondarily disrupt sleep. A case study and an open-label trial with SSRIs suggest that they may treat NES effectively. Randomized controlled trials are needed.     

Binge eating disorder and night eating syndrome: psychological and behavioral characteristics.

OBJECTIVE: The present study was designed to examine the psychological and behavioral characteristics associated with both night eating syndrome (NES) and binge eating disorder (BED) in 42 males and 41 females who were enrolled in a university-based weight loss center. METHOD: Individuals were classified into one of four groups: NES only (N = 23), BED only (N = 13), both NES and BED (N = 13), or no diagnoses of an eating disorder (N = 34). Analyses of covariance (covarying for age and gender) were conducted to compare patients with BED and NES. RESULTS: NES patients scored lower on disinhibition than BED patients (p <.01). Also, individuals who met criteria for both disorders scored higher than NES only patients on state anxiety (p <.01), disinhibition (p =.08), and trait anxiety (p =.08). DISCUSSION: These results suggest that NES represents a subcategory among the obese, which also overlaps with binge eaters. In addition, anxiety distinguished individuals who met criteria for both disorders from patients who were diagnosed with either NES or BED.     

Clinical trial of sertraline in the treatment of night eating syndrome

OBJECTIVE: To test the efficacy of sertraline in the treatment of night eating syndrome. METHODS: Seventeen patients meeting criteria for night eating syndrome received sertraline in a 12-week open-label, nonblind trial. Outcome was assessed by four primary measures, namely, the number of nocturnal awakenings, the number of ingestions, total daily caloric intake after the evening meal, and an overall rating of change from the Clinical Global Impression of Improvement scale (CGI-I). RESULTS AND DISCUSSION: An intent-to-treat analysis revealed highly significant improvements across all four primary outcome measures for all 17 subjects. Five subjects achieved full remission of symptoms (CGI-I score of 1 = very much improved) and lost a significant amount of weight over the course of the study (-4.8 +/- 2.6 kg, p < .05). Sertraline, a selective serotonin reuptake inhibitor, may be beneficial in the treatment of night eating syndrome.     

Eating style and eating behaviour in adolescents.

The relationship between eating style, attitudes towards food and food intake was investigated in 846 British adolescent schoolchildren. Eating style was assessed with the Dutch Eating Behaviour Questionnaire, attitudes towards food with a series of specially prepared questions, and food intake with a diet history taken by a dietitian. The results showed that restraint, external and emotional eating were associated with very different profiles of attitudes and behaviour. Restrained subjects had a higher body weight, more negative attitudes towards food, a lower likelihood of overeating and a lower overall energy intake. External eaters had a lower body weight, positive attitudes to food, and reported a higher energy intake. Emotional eaters fell in between in some ways, with some signs of situational loss of control combined with a negative attitude towards overeating. While external eating appeared to be attenuated by restraint, emotional eating was enhanced by it. The implications of these eating styles for later patterns of eating and weight are discussed.     

Night eating is associated with emotional and external eating in college students

The night eating syndrome (NES) consists of evening hyperphagia and/or nocturnal eating and has been associated with depressed mood that worsens in the evening. However, it is not consistently related to elevated BMI. The present study was conducted to examine whether a relationship exists between NES and emotional, external, and restrained eating. BMI and sleep quality were also obtained. A sample of 246 students completed the Night Eating Diagnostic Questionnaire (NEDQ), Night Eating Syndrome History and Inventory (NESHI), Sleep Quality Index (SQI), and Dutch Eating Behavior Questionnaire (DEBQ), containing subscales for emotional, external, and restrained eating. They also provided demographic information, including height and weight. Participants were grouped by severity of NES features using the NEDQ and NESHI: normal, mild night eater, moderate night eater, and full night eater syndrome. MANOVA was used to compare DEBQ subscores for the groups; those in the full syndrome category had significantly higher emotional eating scores and external eating scores than those in the normal and mild categories. There was no difference in restrained eating between the normal and full syndrome groups. Those with moderate and full syndrome NES symptoms also reported significantly lower sleep quality. No significant relationship was found between NES and BMI. The results show that NES is associated with more eating in response to negative mood and in response to food cues.     

Modeling circadian rhythms of food intake by means of parametric deconvolution: results from studies of the night eating syndrome

BACKGROUND: Disordered temporal eating patterns are a feature of a number of eating disorders. There is currently no standard mathematical model to quantify temporal eating patterns. OBJECTIVE: We aimed to develop a simple model by which to describe the temporal eating patterns of adult humans. For this purpose, patients with the night eating syndrome (NES) and persons without an eating disorder were assessed. DESIGN: Data were obtained from 2 studies, each involving patients with NES and control subjects. Data were analyzed by means of a novel equation to describe the 24-h temporal eating patterns. The equation employed the integration over time of 3 Gaussian equations to describe the cumulative daily caloric intake. RESULTS: The new model accurately described and quantified the temporal eating patterns of the subjects in the 2 studies. The analyses showed differences in the temporal eating patterns and in the amount of intake of normal-weight and overweight subjects with NES. CONCLUSIONS: This novel model can be used to accurately and objectively describe and quantify temporal food intake patterns. It can also be used to establish norms for various human populations.     

Nighttime eating: commonly observed and related to weight gain in an inpatient food intake study

BACKGROUND: Nighttime food intake has rarely been studied in inpatient settings and only one study observed a relation between self-reported nighttime eating and weight gain. OBJECTIVE: We investigated the prevalence of nighttime eating and its effect on weight change. DESIGN: Healthy nondiabetic Pima Indians (n = 117; 67 M, 50 F) and whites (n = 43; 29 M, 13 F) were admitted to a clinical research unit. After consuming a standardized diet for 3 d, participants ate ad libitum from a computer-operated vending machine that recorded the time of food selection. Energy intake was calculated as mean kcal/d. Follow-up weight was available for 94 volunteers. RESULTS: Fifty-five subjects (36%) were nighttime eaters (NEs; persons who ate between 2300 and 0500 on > or =1 of the 3 d). Prevalence was similar among whites and Pima Indians (37% and 35%, respectively). There were no significant differences in body mass index or percentage body fat between NEs and non-NEs. NEs consumed more calories per day (4758) than did non-NEs (4244; P = 0.02), but the percentage of calories from macronutrients did not differ. NEs consumed approximately 15% (690 kcal) of their daily energy during nighttime episodes. After control for baseline weight and follow-up time (x +/- SD: 3.4 +/- 1.8 y), NEs (n = 29) gained more weight (6.2 kg) than did non-NEs (n = 65; 1.7 kg; P = 0.03). CONCLUSIONS: Nighttime eating was common, and it predicted weight gain. It remains to be determined whether this behavior indicates abnormal sleep patterns leading to nighttime wakefulness and food intake in those prone to weight gain.     

Psychological measures of eating behavior and the accuracy of 3 common dietary assessment methods in healthy postmenopausal women

BACKGROUND: Factors affecting the accuracy of reported energy intake (rEI) need to be identified. OBJECTIVE: Our objective was to investigate the association of psychological measures of eating behavior with the accuracy of rEI assessed by 7-d weighed intakes, a 24-h recall, and a food-frequency questionnaire. DESIGN: Subjects were 26 restrained eaters aged 60.3 +/- 0.6 y (mean +/- SEM) and weighing 63.8 +/- 1.7 kg and 34 unrestrained eaters aged 59.4 +/- 0.6 y and weighing 64.0 kg. rEI was assessed by using 3 dietary assessment methods and total energy expenditure (TEE) was determined by using doubly labeled water. Calculated EI (cEI) was determined as TEE corrected for the estimated change in body energy. Subjects completed the Eating Inventory. RESULTS: rEI values were significantly lower than TEE values for all 3 dietary assessment methods (P < 0.05); there was no significant relation between rEI and TEE by any method. There was no significant difference in 100 x rEI:TEE between restrained and unrestrained eaters by any of the dietary assessment methods. When combined data from the 3 methods were used, 100 x rEI:cEI was not significantly different from 100% in unrestrained eaters (99 +/- 6.8%) but was lower in restrained eaters (89.1 +/- 5.3%; P < 0.05). There was a positive relation between hunger and 100 x rEI:TEE (P < 0.05). CONCLUSIONS: Low hunger is associated with undereating relative to normal eating during measurement of dietary intake; high dietary restraint may be associated with a reduction in reporting of consumed foods. Dietary hunger and restraint assessed with use of the Eating Inventory may help to identify subjects likely to underreport dietary intake.     

The effects of energy content and sweet taste on food consumption in restrained and non-restrained eaters

To characterize restrained eating behavior, we fed pudding mixtures (preloads) varying in energy content and sweet taste to subjects before measuring their intake of a variety of appetizing foods in a laboratory setting. Twenty-four female subjects were divided into three groups: normal-weight restrained eaters (no. = 8), normal-weight non-restrained eaters (no. = 7), and over-weight restrained eaters (no. = 9). Classification of subjects was based on body mass and restrained eating score. Five preloads varying in energy content (393 or 67 kcal) and type of sweeteners (sucrose or cyclamate) were served 1/2 hour before test meals of assorted hors d'oeuvres. Subjects were not informed of the specific aim of the study, and were instructed to eat until full. Multivariate analysis of variance of repeated measures showed that food intake of all subjects was higher after eating low-energy preloads than after eating high-energy preloads, although subjects did not recognize the effect in self-reports (p less than .01). The energy intake of restrained normal-weight eaters was significantly (p less than .05) lower after eating sweet preloads than after eating non-sweet preloads. Findings suggest that a food-intake control mechanism responds to short-term energy deficits among subjects of varied body mass and restrained eating indexes. J Am Diet Assoc 90:1223-1228, 1990.     

Night eating syndrome among nonobese persons

OBJECTIVE: To compare the characteristics of obese persons with the night eating syndrome (NES) with those of nonobese persons with the NES. METHODS: Eighty subjects (40 with a body mass index [BMI] greater than 30 and 40 with a BMI less than 25) identified themselves on a website for the Night Eating Questionnaire (NEQ) as suffering from the NES. The responses of the 40 obese website subjects were compared with 21 obese persons with the NES who had undergone face-to-face interviews. The responses on the NEQ of the 40 obese and the 40 non-obese website subjects were then compared. RESULTS: There was no difference in the NEQ results of the 40 website obese subjects and 21 obese night eaters who had undergone face-to-face interviews. The responses of these same 40 obese subjects showed very little difference compared with those of the 40 nonobese subjects. The major difference between the two groups was the considerable younger age of the normal-weight NES subjects. DISCUSSION: The striking similarity in the characteristics between obese and nonobese subjects with the NES indicates that this disorder, considered until now to occur primarily among obese persons, also occurs among nonobese persons. The younger age of the nonobese subjects suggests that the NES may contribute to the development of obesity.     

Recorded food intake of obese women with binge eating disorder before and after weight loss

Because binge eating in obese individuals has been postulated to be a reaction to dietary restriction, we examined the recorded food intake of 17 obese women with and 16 obese women without binge eating disorder (BED) during 1-week periods before and 3 months after a very low calorie diet program in order to determine the effects of dietary restriction on binge eating frequency and severity. Before weight loss, rather than reporting severe caloric restriction, women with BED reported greater average energy intake than nonbinge eaters on both a total (2707 vs. 1869 kcal/day, p < .01) and weight-adjusted (25.1 vs. 18.1 kcal/kg, p < .01) basis, with both higher intake on nonbinge days and an increased frequency of binge days. After weight loss, there was no significant difference in energy intake, on either a total or weight-adjusted basis, between subjects with and without BED. Although average daily energy intake fell for both groups after weight loss, only subjects with BED reported significantly decreased energy intake when adjusted for change in body weight. This resulted from decreased intake on nonbinge days and a decreased frequency of binge days. Before weight loss, subjects with BED reported an average energy intake equivalent to 94% of their predicted energy expenditure. Whereas subjects without BED reported intake only 64% of predicted (p = .002). After weight loss, there was no significant difference between subjects with and without BED in the percentage of predicted energy expenditure reported as intake (64% vs. 58%). Restraint was similar in both groups before weight loss, but those with BED reported greater hunger and disinhibition. After weight loss treatment, restraint increased significantly, whereas disinhibition and hunger remained elevated in subjects with BED. Disinhibition, rather than restraint, appears to be a major contributor to the disordered eating of these individuals. Unlike normal-weight women with bulimia nervosa, dietary restriction does not appear to worsen symptoms of bingeeating in obese women with BED. Over the short term, subjects with BED may respond to a standard weight loss treatment program with improvements in binge eating behaviors. © 1994 by John Wiley & Sons, Inc.     

Familial aggregation in the night eating syndrome

OBJECTIVE: This study examined the extent to which the night eating syndrome (NES) affects first-degree relatives of NES and control probands. METHOD: NES participants and controls were assessed with the Night Eating Questionnaire (NEQ), the Night Eating Syndrome History and Inventory (NESHI), 10 day sleep and food records, the Eating Disorder Examination (EDE), the Structured Clinical Interview for DSM IV Axis I Disorders (SCID I), and a Family History Questionnaire (FHQ) to assess the presence of NES among first-degree relatives. A proband predictive model, using logistic regression analyses and the generalized estimating equation to control for correlation among observations within families was used to assess familial aggregation. RESULTS: The odds of an NES proband having an affected first-degree relative were significantly greater than that of a control proband (odds ratio=4.9, p<.001). A number of covariates were included in the model: proband body mass index (BMI) (kg/m2), proband gender, proband age, proband ethnicity, first-degree relative gender, relationship to proband (i.e., mother, father, or sibling), and the interaction between relationship to proband and proband status (night eater or control); none was statistically significant (p>.05). CONCLUSION: The study showed a strong aggregation of NES in families.     

Affective and cognitive antecedents to eating episodes in bulimia and binge eating

The present study investigated seven antecedents to the binge-purge cycle proposed by Orleans and Barnett (1984), including restraint, stress, mood, thoughts of food, fatigue, hunger, and dichotomous cognitions. For 1 week, 19 bulimics, 15 binge eaters, and 20 normal control subjects recorded detailed information about these antecedent conditions and the types and quantities of food consumed for each eating episode. Results indicated that prior to their binge episodes, bulimics reported significantly greater stress, preoccupation with food, and negative mood than binge eaters reported prior to their binges and normal controls reported prior to all of their eating episodes. Both bulimics and binge eaters reported greater dichotomous cognitions prior to binge episodes than normal controls experienced prior to all of their eating episodes. Comparisons of the antecedents to eating episodes which bulimics and binge eaters regarded as nonbinge episodes with all eating episodes of the control group indicated that although bulimics and binge eaters experienced significantly greater negative moods than normal controls prior to their nonbinge episodes, only bulimics experienced significantly greater dichotomous cognitions prior to these eating episodes. Theoretical and clinical implications of these findings are discussed.     

Diurnal secretion of ghrelin, growth hormone, insulin binding proteins, and prolactin in normal weight and overweight subjects with and without the night eating syndrome

The regulatory peptide ghrelin has been proposed to help mediate both hunger and sleep. The neuroendocrine circadian patterns in the night eating syndrome (NES) have been distinguished by an attenuated nocturnal rise in the plasma concentrations of melatonin and leptin and a greater increase in the concentrations of cortisol. In this study we wanted to test the hypothesis that night eaters have disturbances in the circadian levels of ghrelin, growth hormone (GH) and associated regulatory peptides. In 12 female night eaters (6 normal weight and 6 overweight), and 25 healthy controls (12 normal weight and 13 overweight), blood was sampled over a 24-hour period. Four meals were served from 8 AM to 8 PM, and blood samples were drawn every second hour for determination of plasma ghrelin concentrations and GH by radioimmunoassay (RIA). Analysis of serum GH, IGF-1, IGFBP-3 and prolactin were performed by ELISA. In healthy normal weight subjects there was a slight but non significant nocturnal increase of ghrelin, whereas a more or less flat curve was observed for healthy overweight, NES normal weight and NES overweight patients. The RMANOVA analysis showed a significant independent lowering effect of overweight on the grand mean of ghrelin. No direct effects on NES normal weight and overweight subjects were found, but a near-significant interaction was found between healthy overweight and overweight NES subjects. There were independent significant lowering effects of overweight and NES on the serum GH levels. During the time course no changes in the serum levels of IGF-1 or IGFB-3 were observed. Independent significant lowering effects of overweight and NES on the levels of IGF-1 were detected, whereas a near significant reduction in the global levels of IGFBP-3 was observed in both NES groups. Finally, significant nocturnal changes were observed for serum levels of prolactin in all four subgroups. Grand mean levels tended to be higher in NES subjects whereas the opposite was observed in healthy overweight (ns). We conclude that in both NES groups and in healthy overweight subjects more or less attenuated ghrelin and GH secretions were observed, whereas divergent secretions were observed for prolactin.     

Energy expenditure and everyday eating behavior in healthy young women

The doubly labeled water method was used to measure average daily total energy expenditure (EE) in 23 healthy normal-weight women classified as restrained or unrestrained eaters. Although the relative weight of restrained eaters was found to be higher (BMI 21.1 +/- 1.3 vs 20.0 +/- 1.3 kg/m2, p less than 0.03), the self-reported energy consumption of the restrained eaters, when adjusted for body composition and height, totaled approximately 410 kcal/d less energy than that of the unrestrained group (p less than 0.002). Correspondingly, the adjusted EE was found to be lower by 620 kcal/d in restrained eaters (p less than 0.005). In both groups metabolic indices of starvation (beta-hydroxybutyric acid and triiodothyronine) were in the normal range. Neither these nor weight changed from the beginning to the end of the 14-d observation period. Thus, the lower EE of the restrained group reflects diminished caloric requirements and is not an adaptive response to a temporary decrease in food intake.     

Evaluation of diagnostic criteria for night eating syndrome using item response theory analysis

Uniform diagnostic criteria for the night eating syndrome (NES), a disorder characterized by a delay in the circadian pattern of eating, have not been established. Proposed criteria for NES were evaluated using item response theory (IRT) analysis. Six studies yielded 1,481 Night Eating Questionnaires which were coded to reflect the presence/absence of five night eating symptoms. Symptoms were evaluated based on the clinical usefulness of their diagnostic information and on the assumptions of IRT analysis (unidimensionality, monotonicity, local item independence, correct model specification), using a two parameter logistic (2PL) IRT model. Reports of (1) nocturnal eating and/or evening hyperphagia, (2) initial insomnia, and (3) night awakenings showed high precision in discriminating those with night eating problems, while morning anorexia and delayed morning meal provided little additional information. IRT is a useful tool for evaluating the diagnostic criteria of psychiatric disorders and can be used to evaluate potential diagnostic criteria of NES empirically. Behavioral factors were identified as useful discriminators of NES. Future work should also examine psychological factors in conjunction with those identified here.     

The application of ecological momentary assessment to the study of night eating

OBJECTIVE: Night eating syndrome (NES) was first described in 1955 by Albert Stunkard and colleagues. NES consists of either overeating at night or waking up during the night and eating. METHOD: In the current study we used ecological momentary assessment (EMA) to describe 14 self-defined night-eaters. The participants in the current study completed an EMA protocol of approximately two weeks. RESULTS: We found that ratings of hunger appeared to be higher during night awakenings than in the evening. Also, both affect and arousal generally decreased throughout the day and were lowest during awakening episodes. CONCLUSION: The current study adds interesting data in describing the experience of night-eating behavior with ecological momentary assessments from self-described night-eaters.