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

Abstract

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.

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

“…For example, de Zwaan et al [ 7 ] found that across studies, the prevalence of NES in pre-operative bariatric patients ranged from 6 to 64% [ 7 ]. In attempt to elucidate the prevalence of NES using only the DSM-5 diagnostic criteria, Kaur et al [ 8 ••] reviewed the most up-to-date empirical literature, concluding that the overall prevalence of NES ranged from 2.8 to 8.2% across eating disorder, obesity, and bariatric surgery populations. Further, Kaur et al noted that when the cut-off score on the Night Eating Questionnaire (NEQ) (an assessment tool detailed in the assessment section) was decreased from 30 to 25, the prevalence of NES within these clinical populations increased (6.9 to 15.2%) [ 8 ••].…”

“…In attempt to elucidate the prevalence of NES using only the DSM-5 diagnostic criteria, Kaur et al [ 8 ••] reviewed the most up-to-date empirical literature, concluding that the overall prevalence of NES ranged from 2.8 to 8.2% across eating disorder, obesity, and bariatric surgery populations. Further, Kaur et al noted that when the cut-off score on the Night Eating Questionnaire (NEQ) (an assessment tool detailed in the assessment section) was decreased from 30 to 25, the prevalence of NES within these clinical populations increased (6.9 to 15.2%) [ 8 ••]. These findings underscore the increased frequency of NES across clinical populations, suggesting some populations may be more vulnerable to developing NES.…”

Effect of bariatric surgery on night eating syndrome: A retrospective study

“…Before and after bariatric surgery, eating behavior plays a crucial role in postoperative outcomes [4,5]. Eating disorders and problematic eating behavior, which are more common in bariatric surgery patients compared to the non-obese population, may have adverse effects on post-op bariatric surgery outcomes [6].…”

“…The most frequent eating disorders among the patients who are candidates for bariatric surgery can be listed as; binge eating disorder, night eating syndrome, emotional eating, and frequent snacking or grazing during the day. Moreover, although it has not yet been included in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders-5), food addiction also appears in studies carried out [6,8,9]. The literature indicates that binge eating disorder is observed in 4-45%, grazing in 20-60%, night eating syndrome in 42%, emotional eating in 38-59%, and food addiction in 36.8% of bariatric surgery candidates [8,10,11].…”

“…The literature indicates that binge eating disorder is observed in 4-45%, grazing in 20-60%, night eating syndrome in 42%, emotional eating in 38-59%, and food addiction in 36.8% of bariatric surgery candidates [8,10,11]. The performance of a psychological evaluation before the bariatric surgery for the patients and providing post-op support through psychological follow-up for the patients with a diagnosed eating disorder are among the factors that will lead the patient to success after the surgery [6,12].…”