Night eating syndrome in patients with eating disorders: Is night eating syndrome distinct from bulimia nervosa?

Sleep quality in eating disorders: A systematic review and meta-analysis

Eating disorders (ED) are psychological disorders characterized by dangerous eating behaviours, including protracted fasting and binge eating. Mental disorders comorbidities (e.g., anxiety and depression), as well as sleep difficulties, are common and might interfere with treatment response. This work investigated sleep quality, circadian preferences, and sleep disorders in ED patients compared to healthy controls (HC) and the impact of ED treatment on patients' sleep. A literature search on Pubmed, Web of Science, Medline, and PsychInfo included 27 studies. Random effect analyses were performed (sample eating disorders = 711; sample healthy controls = 653) and subgroup analyses were calculated based on the ED subgroups: Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder. Whole sample analyses showed poorer physiological and subjective sleep quality in patients. Subgroup analyses showed that poorer physiological sleep was present only in anorexia nervosa. Two studies reporting circadian preferences and sleep disorders showed higher evening preference in patients and no differences in apnea prevalence between patients and healthy controls, respectively. Some studies suggested that specialized eating disorder treatments (e.g., Cognitive Behavioural Therapy for ED) can improve sleep quality in patients. Although these findings highlight poorer sleep in patients with ED compared to healthy controls, the mechanisms underlying sleep alterations in eating disorders remain to be identified.

There is nothing as inconsistent as the OSFED diagnostic criteria

Atypical anorexia nervosa (AAN), purging disorder (PD), night eating syndrome (NES), and subthreshold bulimia nervosa and binge-eating disorder (Sub-BN/BED) are the five categories that comprise the 'Other Specified Feeding or Eating Disorder' (OSFED) category in the Diagnostic and Statistical Manual for Mental Disorders (DSM-5). In this review, we examine problems with the diagnostic criteria that are currently proposed for the five OSFED types. We conclude that the existing diagnostic criteria for OSFED are deficient and fall short of accurately describing the complexity and individuality of those with these eating disorders (EDs). Therefore, to enhance the quality of life of people with OSFED, diagnostic criteria for the condition should be applied uniformly in clinical and research settings.

A Scoping Review on the Association between Night Eating Syndrome and Physical Health, Health-Related Quality of Life, Sleep and Weight Status in Adults

Night eating syndrome (NES) is characterised by recurrent episodes of night eating, evident through excessive food consumption after the evening meal or eating after awakening from sleep, often associated with significant distress and/or impairment in functioning. This scoping review was conducted according to PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews) guidelines. The search was conducted through the use of PubMed, Medline (OVID) and SCOPUS, to identify relevant articles published within the last 10 years. Search terms including "Night eating*" OR "NES" and Boolean phrases were used to refine the search. Additionally, the age of participants was restricted to 18 years and above, to ensure only adult participants were included. The abstracts of the remaining articles were used to screen for those that were relevant. From a total of 663 citations, 30 studies assessing night eating syndrome met the inclusion criteria to be included in the review. We found inconsistent associations of NES with higher body mass index (BMI), less physical activity, type 2 diabetes mellitus (T2DM) and poorer quality of sleep. These inconsistencies may have been due to the use of different measurement methods, lack of power from small sample sizes of NES in some studies and varying ages of participants, with associations being more likely to be found in higher-quality, representative populations than in university student samples. There were no associations of NES with T2DM in clinical populations and with hypertension, OSA and metabolic syndrome, but sample sizes were small. The impacts of NES on these medical conditions should be addressed in future, using well-sized and long-term studies involving representative populations of adults. In conclusion, NES likely has negative impacts on BMI, T2DM, physical activity, and sleep quality, which in turn may increase cardio-metabolic risk. However, further research is needed to elucidate the interaction between NES and its associated features.

Night eating syndrome subtypes: differences in binge eating and food addiction symptoms

PURPOSE

The purpose of the current study was to examine differences in binge eating and food addiction symptoms between Night Eating Syndrome (NES) latent subtypes: evening hyperphagia with nocturnal ingestions (EHNI), evening hyperphagia-only (EHO), and nocturnal ingestions-only (NIO). It was hypothesized that the EHNI group would report more binge eating behaviors and more food addiction symptoms than both the EHO and NIO groups. Further, it was hypothesized that the EHO and NIO groups would differ with the EHO group reporting more binge eating behaviors and the NIO group reporting more food addiction symptoms.

METHODS

Participants completed measures online relating to night eating, binge eating, and food addiction. Average age of the final sample was 34.3 (SD = 10.5) and 62.0% were men. Responses to the Night Eating Questionnaire (NEQ; Allison et al., 2008) were used to create an EHNI group (n = 65), an EHO group (n = 32), and a NIO group (n = 69). ANOVAs were conducted to examine between-group differences on disordered eating symptoms.

RESULTS

Participants in the EHNI group reported more severe binge eating and food addiction symptoms than those in the EHO and NIO groups. However, there were no significant differences in binge eating or food addiction between the EHO and NIO groups.

CONCLUSION

Individuals who meet both NES core criteria (evening hyperphagia and nocturnal ingestions) are likely at a higher risk for experiencing other, more severe disordered eating pathologies. Implications concerning assessment and future research on NES typology are discussed.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

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.

Personality traits and night eating syndrome in women with bulimia nervosa and binge eating disorder

PURPOSE

Previous research suggests that eating disorders may be associated with certain personality profiles; however, there is limited research investigating associations with night eating syndrome (NES). This research suggests harm avoidance personality trait is higher in NES individuals than in the general population, however, evidence of associations with other personality traits is inconsistent. To understand which personality traits are associated with NES symptoms, the current study aimed to improve understanding of the relationship between NES symptoms and a range of personality traits, addressing limitations in the earlier literature in this area by controlling for common confounders.

METHODS

Baseline data were analysed from an outpatient psychotherapy trial for 111 women with bulimia nervosa or binge eating disorder. Pre-treatment measures of personality traits (measured with the Temperament and character inventory-revised) and NES symptoms (measured with the Night eating questionnaire) were used. Regression analyses tested associations between these variables, adjusting for potential confounders, including age and ethnicity.

RESULTS

Low cooperativeness scores were associated with greater NES symptoms in the multivariable model (mean difference: - 0.10, 95% confidence intervals: - 0.20 to - 0.01, p = 0.033). There was weak evidence of associations between both high harm avoidance and low self-directedness personality traits and greater NES symptoms.

CONCLUSIONS

This study adds to the limited research measuring associations between a range of personality traits and NES, addressing limitations of previous research. Weak evidence for an association between high harm avoidance and low self-directedness and increased NES symptoms was found. A novel association was found between low cooperativeness and greater NES symptoms. Further research is needed to validate its presence in those with and without comorbid eating disorders and to examine the relative change in NES, eating disorder symptoms and personality scores in treatments focusing on cooperativeness.

LEVEL OF EVIDENCE

Level IV (cross-sectional data from a randomised controlled trial, CTB/04/08/139).

'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.

Night Eating Syndrome in Patients With Obesity and Binge Eating Disorder: A Systematic Review

Night eating syndrome (NES) is currently classified as an Other Specified Feeding or Eating Disorder (OSFED) under the Diagnostic Statistical Manual−5 (DSM-5). This systematic review aims to consolidate the studies that describe the sociodemographic, clinical and psychological features of NES in a population of patients with eating disorders (ED), obesity, or those undergoing bariatric surgery, and were published after the publication of the DSM-5. A further aim was to compare, where possible, NES with BED on the aforementioned variables. Lastly, we aimed to appraise the quality of the studies being included in the review. We conducted a systematic search on three databases (MEDLINE, PubMed and Embase) which resulted in the selection of 22 studies for the review. We included the articles that studied patients with NES and their sociodemographic, clinical and psychological features in a clinical (i.e., ED, obese or bariatric surgery) population, through a quantitative study design. Articles were excluded if the NES patients included in the study had a comorbid psychological disorder, and/or the sample was collected from a university/non-clinical population, and/or the study design was qualitative, and/or NES features were compared with any other disorder, except BED. Our study found that no conclusions about the link between any sociodemographic feature (such as, age, gender, income, etc.) and an NES diagnosis could be made. Further, NES patients presented with elevated ED pathology (including emotional eating and loss of control eating) and higher occurrence of depressive symptoms than controls. Contrary to the literature suggesting that NES and Binge Eating Disorder (BED; an ED subtype which is also comorbid with obesity) patients often report overlapping features, questioning the validity of NES as an ED diagnosis, we found that BED can be differentiated from NES by the higher occurrence of emotional eating, body related concerns and abnormal eating episodes. The review also suggested an overlap between NES and Sleep-Related Eating Disorder. We recommend that it is essential to study NES as an independent disorder to further develop its diagnostic criteria and treatment options, thereby, increasing the quality of life of the patients suffering from this syndrome.

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.

Sleep Quality and Eating Disorder-Related Psychopathologies in Patients with Night Eating Syndrome and Binge Eating Disorders

Night eating syndrome (NES) is an eating disorder (ED) characterized by nocturnal ingestion (NI), evening hyperphagia, morning anorexia, as well as mood and sleep disturbances. This study compared subjective and objective sleep quality and ED-related psychopathologies in patients seeking treatment for ED. Method: The sample was composed of 170 women, aged 18–68, who were referred for an ED assessment from 2011 to 2020. The participants were divided into three subgroups: NES-NI only (n = 30), NES+ binge eating (BE) (including binge eating disorders or bulimia nervosa (n = 52), and BE-only (n = 88). The measures consisted of a psychiatric evaluation, objective sleep monitoring measured by an actigraph for 1 week, a subjective sleep self-report, and ED-related psychopathology questionnaires. Results: Objective sleep monitoring revealed significant group differences, with higher sleep efficiency in participants with BE-only and longer sleep durations for the NES-NI only group. Subjectively, the BE-only group described a significantly lower sleep quality than either the NES-NI only or the NES+BE groups. ED-related psychopathology was lower in the NES-NI-only group. A stepwise linear regression revealed that general psychopathology (the brief symptom inventory total score) was a significant predictor of subjective sleep quality. Conclusion: NES-NI-only was correlated with less psychopathology, but with more subjective and objective sleep disturbances. These results lend weight to the supposition that NES lies on a continuum of ED psychopathologies, and that NES-NI-only appears to be a separate entity from NES+BE and BE-only in terms of its psychopathology.

Eating patterns and unhealthy weight control behaviors are associated with loss-of-control eating following bariatric surgery

BACKGROUND

Loss-of-control (LOC) eating is associated with poor weight-loss outcomes following bariatric surgery. It is not clear whether eating patterns (e.g., total number of daily meals/snacks, eating after suppertime, eating when not hungry) and unhealthy weight control behaviors (e.g., smoking, using laxatives) are associated with or predictive of LOC eating.

OBJECTIVES

To examine whether eating patterns and unhealthy weight-control behaviors are associated with LOC eating and, if so, whether they predict LOC eating in bariatric patients.

SETTING

Multicenter study, United States.

METHODS

This is a secondary analysis of the Longitudinal Assessment of Bariatric Surgery-2 study. Assessments were conducted before surgery and at 12, 24, 36, 48, 60, and 84 months after surgery. Logistic mixed models were used to examine the longitudinal associations between eating patterns, unhealthy weight-control behaviors, and LOC eating. Time-lag techniques were applied to examine whether the associated patterns and behaviors predict LOC eating.

RESULTS

The participants (n = 1477) were mostly women (80%), white (86.9%), and married (62.5%). At the time of surgery, the mean age was 45.4 ± 11.0 years and the mean body mass index was 47.8 ± 7.5 kg/m². The total number of daily meals/snacks, food intake after suppertime, eating when not hungry, eating when feeling full, and use of any unhealthy weight-control behaviors were positively associated with LOC eating (P < .05). Food intake after suppertime, eating when not hungry, and eating when feeling full predicted LOC eating (P < .05).

CONCLUSION

Meal patterns and unhealthy weight control behaviors may be important intervention targets for addressing LOC eating after bariatric surgery.

Prevalence and Associated Factors of Nocturnal Eating Behavior and Sleep-Related Eating Disorder-Like Behavior in Japanese Young Adults: Results of an Internet Survey Using Munich Parasomnia Screening

Nocturnal (night) eating syndrome and sleep-related eating disorder have common characteristics, but are considered to differ in their level of consciousness during eating behavior and recallability. To date, there have been no large population-based studies determining their similarities and differences. We conducted a cross-sectional web-based survey for Japanese young adults aged 19-25 years to identify factors associated with nocturnal eating behavior and sleep-related eating disorder-like behavior using Munich Parasomnia Screening and logistic regression. Of the 3347 participants, 160 (4.8%) reported experiencing nocturnal eating behavior and 73 (2.2%) reported experiencing sleep-related eating disorder-like behavior. Smoking (p < 0.05), use of hypnotic medications (p < 0.01), and previous and/or current sleepwalking (p < 0.001) were associated with both nocturnal eating behavior and sleep-related eating disorder-like behavior. A delayed sleep-wake schedule (p < 0.05) and sleep disturbance (p < 0.01) were associated with nocturnal eating behavior but not with sleep-related eating disorder-like behavior. Both nocturnal eating behavior and sleep-related eating disorder-like behavior had features consistent with eating disorders or parasomnias. Nocturnal eating behavior but not sleep-related eating disorder-like behavior was characterized by a sleep-awake phase delay, perhaps representing an underlying pathophysiology of nocturnal eating syndrome.

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.

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.