Continuing Education Activity

Night eating syndrome (NES) is an eating disorder characterized by excessive food intake in the evening or nighttime. It involves consuming at least 25% of daily calories after dinner and frequent nocturnal awakenings to eat. NES is linked to psychological, neurological, and genetic factors and often occurs alongside obesity-related complications like diabetes. Patients may be reluctant to disclose their symptoms, and the condition can be misdiagnosed. Effective management requires ruling out other eating or mood disorders and implementing a combination of therapies such as selective serotonin reuptake inhibitors (SSRIs), light therapy, and relaxation techniques.

Participants in this course gain a thorough understanding of the diagnosis and management of night eating syndrome, including how to identify its unique clinical features and exclude other disorders. The course emphasizes the importance of addressing the psychological and neurological aspects of NES and highlights effective treatment strategies. Through interprofessional collaboration—among nutritionists, psychologists, primary care providers, and endocrinologists—healthcare teams can improve patient outcomes by providing comprehensive care tailored to both the mental and physical aspects of the disorder. This collaboration ensures that patients receive holistic treatment and long-term support.

Objectives:

• Assess the clinical evaluation of night eating syndrome.
• Identify the pathophysiology of night eating syndrome.
• Identify the differential diagnoses of night eating syndrome.
• Develop the appropriate management of night eating syndrome with prognosis in collaboration with the interprofessional team.

Introduction

Night eating syndrome (NES) is a type of eating disorder related to eating after dinner and when awake at night. Wolff, Stunkard, and Grace discovered this condition in a group of patients seeking weight loss treatment.[1] The syndrome was identified when their patients reported consuming a caloric intake of 25% of daily calories or more at night.[1] Night eating syndrome is characterized by at least 3 of the following symptoms:

• A strong urge to eat between dinner and going to bed
• Anorexia in the morning and during the night
• Maintenance or sleep onset insomnia
• Depressed mood
• Evening mood worsening
• The belief that one cannot sleep without eating [2][3]

Etiology

The etiology of night eating syndrome has remained unknown. Recent research results have proposed a link between a psychological course and neurological and genetic processes. For example, results from a study by Lamerz and colleagues conducted on children in Germany showed that patients were more likely to develop night-eating syndrome if their mothers had night-eating behavior. These patients were compared to children of mothers who did not have night eating behavior.[4] 

A recent study compared night eating behaviors in families with a person with the condition to those without one. The results showed that those with NES had first-degree relatives with the disorder more often than the control group, suggesting a heritability aspect to the disorder.[5] Stress can exacerbate the symptoms of the disorder, and symptoms can be alleviated by decreasing stress levels.[1] The initial onset and maintenance of the condition were shown by recent studies to be directly caused by stress and other psychiatric disorders like depression.[6]

Epidemiology

In the United States, the prevalence of night eating syndrome is 1.5%. NES prevalence is similar to other binge eating disorders like bulimia nervosa and anorexia nervosa.[7][8] This condition is more frequently seen in obese populations, although not all individuals with NES are, in fact, obese.[9][10] Results from a study in Sweden revealed a 2.5 times higher prevalence of NES in men with obesity along with a 2.8 times higher prevalence in women with obesity in comparison to nonobese of both genders.[11] 

A NES prevalence between 6% and 64% was found among obese individuals looking for weight loss surgery in a review conducted by de Zwaan, Mitchell, Burgard, and Schenck. Antother study's results showed that up to 55% of individuals seeking bariatric surgery have reported some symptoms of NES.[12] NES typically appears in the late teens to late twenties. NES also appears to be long-lasting, with relapse and remission tethered to stressors.[13][14] A Swedish twin registry participant in an interview-based study had results that revealed more women than men meet all criteria for NES.[15] These findings could suggest that all sexes experience NES symptoms equally. However, women s are morenegatively affected.[15] 

Those with NES are more likely to have another eating disorder than the non-NES population, with a 5 to 44% prevalence.[9] Overlapping symptoms between NES and binge eating disorder have been showns 15% to 20% of patients with NES. However, the conditions are differentiated by the quantity of food eaten per meal, the motivation for eating, and the concern about weight and shape.[16] Patients were recruited into a study by Lundgren from outpatient clinics using the NES screening questionnaire. They were asked about their evening food cravings, nocturnal ingestions, morning anorexia, and the sum of awakenings. The criteria for NES were met in 12.3% of the study participants, and it was found that those patients were also obese.[17][18]

Pathophysiology

Researchers believe that cognitions and a wide range of emotions might play a major role in developing NES; most symptoms occur at night due to the belief that the individual can not sleep without eating. Patients also feel a need to control the anxiety associated with that belief through eating.[19][20] Cortisol was examined during night eating as this hormone is released during stress associated with overeating.[21][22] Birketvedt and colleagues studied 33 participants, 12 with NES and 21 control subjects. The subjects were fed regular intervals of meals over 24 hours and given no food after 8:00 pm.[23] Blood tests were drawn every 2 hours over the 24 hours, with the results showing higher cortisol levels from 8:00 am to 2:00 am in night eaters compared to those in the control group.[23]

History and Physical

Some study results have determined criteria to include hyperphagia in the evening with 25% or more of daily caloric intake after dinner with not less than 2 nocturnal awakenings during the week to eat.[23][24][25] Additional criteria include the awareness of nocturnal eating habits and recall of the nocturnal eating habits.[2] A clinical picture is described by at least 3 of these criteria:

• Breakfast and morning eating are missed due to a lack of desire [26]
• The urge to eat between the evening meal and bedtime sleep [18][23]
• Difficulty initiating or maintaining sleep occurring for 4 or more nights per week [27]
• The belief that the individual must eat to return to sleep
• The mood that worsens at night or is frequently depressed [27][28][29]

Evaluation

In a randomized control trial done by the Look AHEAD (Action for Health in Diabetes) study, results showed that the diagnosis of NES was more related to patients with a depressed mood.[16][30][26][30][26] The study results also showed that diabetic individuals with obesity have higher body mass index and reported weight problems at much younger life than those without eating disorders.[31] In previous studies, a significant predictor of hemoglobin A1c  of greater than 7 was discovered in individuals with type 1 and type 2 diabetes who reported evening hyperphagia along with 2 or more diabetes complications and obesity.[32]

Treatment / Management

Psychotherapy has been shown to decrease night-eating symptoms. Twenty-five patients were treated with cognitive behavioral therapy by Allison and colleagues within 12 weeks of diagnosis.[33] The interventional study included education, logging sleeping and eating habits, encouraging coping skills, regulating eating and sleep patterns, and weight management.[6][33] The study results showed reductions in weight gain, evening caloric intake, nocturnal ingestions, and recurrent awakenings at night. Treatment also showed improvements in mood enhancement and quality of life.

The serotonin system contributes to the regulation of eating, mood, and sleep. Therefore, it was assumed that reduced serotonin could lead to reduced satiety and circadian rhythm disturbances, leading to increased evening hyperphagia and nocturnal ingestions.[34] In a 12-week clinical trial study on 17 patients treated with sertraline and two additional studies that included randomized controlled trials, the results showed a massive reduction in night awakenings, evening hyperphagia, and calorie consumption after evening meals.[25][35]

The rate for remission was 29%. However, the response rate was 67%.[35] Open-label trial testing escitalopram efficacy revealed a significant reduction in NES symptoms, caloric intake consumed after dinner, and nocturnal ingestions; however, no difference was noticed compared to placebo in a randomized controlled trial.[35][36][37] In a randomized study of 44 patients from both sexes divided into 3 groups: education, education plus progressive muscle relaxation (PMR), or PMR plus exercise. Vander Wal and colleagues concluded that the percentage of food eaten was significantly different between the 3 groups in the study, with the group doing PMR having the most significant reduction.[38] The increase of postsynaptic serotonin has been proven using phototherapy; two case studies used phototherapy to treat symptoms of NES and depression.[39] 

Freidman and colleagues conducted a study using paroxetine and bright light therapy on a 51-year-old woman with depression and NES. The results showed that discontinuation of the phototherapy made her NES symptoms return.[40] The effect of promising light therapy was also studied on 15 patients with NES, and the results showed a tremendous reduction in NES symptoms along with mood and sleep disturbance after treatment.[41]

Differential Diagnosis

Night eating syndrome is usually confused with sleep-related eating disorders. The main differential criterion between NES and sleep-related eating disorders is the nature and the component of nocturnal eating. While the NES is composed of both hyperphagia and nocturnal eating along with awareness, sleep-related eating disorders are mainly characterized by repeated involuntary eating habits during sleep.[2] A sleep-related eating disorder is considered parasomnia due to automatic and poorly recalled eating habits, along with nonfood items consumed, sharing similarities to sleepwalking.[2] 

Night eating syndrome can be classified as an insomnia-related disorder as patients are awake, aware, and able to recall their eating habits. Generally, patients with NES do not report underlying sleep disorders. However, some patients might report both syndromes.[2][42] Sharing the behavior of evening hyperphagia between NES and binge eating disorder does not necessarily mean they share the exact etiology. Unlike binge eating disorder, evening hyperphagia in NES patients is mainly correlated to nocturnal anxiety.[20] In addition, the amount of food consumed in the evening in patients with NES is not as large as in patients with binge eating disorders.[23]

Prognosis

Patients treated for NES with pharmacological, cognitive therapy, and lifestyle changes have noticed a significant improvement in their symptoms.[43] For those who are untreated, many health issues and emotional challenges are related to being overweight or having obesity, such as high cholesterol, diabetes, and high blood pressure.[6]

Complications

Patients with NES commonly become overweight due to increased calorie intake before bedtime. The increased caloric intake results in complications such as diabetes, high blood pressure, cardiac disease, and obesity. Without psychotherapy, psychiatric disturbances can develop.[44] An association between NES and various psychopathologies, particularly depression, was found in most studies.[16][35] Many patients with NES were found to meet lifetime criteria for major depressive disorders, substance abuse, and anxiety disorder.[45][46]

Deterrence and Patient Education

NES is an eating disorder characterized by excessive night eating habits (after dinner) or awakening from sleep to eat (nocturnal ingestions).[6] Additionally, 3 or more symptoms occur: the urge to eat between dinner and sleep, morning anorexia, maintenance insomnia or sleep onset, depressed mood or worsened mood in the evening, and the belief that without eating, one can not get back to sleep.[2][3] The prevalence in the United States is 1.5%, about the same as binge eating disorder.[6] The symptoms are often in remission and relapse according to life stressors, starting early adulthood.[13][14] The treatment includes pharmacological and nonpharmacological therapy, such as cognitive behavioral therapy.[43]

Enhancing Healthcare Team Outcomes

Since most patients do not bring up issues with night eating either due to shame or guilt, it is recommended to use screening questions. The primary care clinician should refer the patient to a psychiatric specialist for appropriate treatment.[6] Patients with type 2 diabetes need to be screened for NES due to the high percentage of patients with pre-existing type 2 diabetes having clinical NES.[47] After diagnosis, treatment should be followed by an interprofessional healthcare team that includes psychiatry, internal medicine, and endocrinology, working with nurses, pharmacists, and other mental health professionals. 

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References

1.

STUNKARD AJ, GRACE WJ, WOLFF HG. The night-eating syndrome; a pattern of food intake among certain obese patients. Am J Med. 1955 Jul;19(1):78-86. [PubMed: 14388031]

2.

Allison KC, Lundgren JD, O'Reardon JP, Geliebter A, Gluck ME, Vinai P, Mitchell JE, Schenck CH, Howell MJ, Crow SJ, Engel S, Latzer Y, Tzischinsky O, Mahowald MW, Stunkard AJ. Proposed diagnostic criteria for night eating syndrome. Int J Eat Disord. 2010 Apr;43(3):241-7. [PMC free article: PMC4531092] [PubMed: 19378289]

3.

de Zwaan M, Marschollek M, Allison KC. The Night Eating Syndrome (NES) in Bariatric Surgery Patients. Eur Eat Disord Rev. 2015 Nov;23(6):426-34. [PubMed: 26395455]

4.

Lamerz A, Kuepper-Nybelen J, Bruning N, Wehle C, Trost-Brinkhues G, Brenner H, Hebebrand J, Herpertz-Dahlmann B. Prevalence of obesity, binge eating, and night eating in a cross-sectional field survey of 6-year-old children and their parents in a German urban population. J Child Psychol Psychiatry. 2005 Apr;46(4):385-93. [PubMed: 15819647]

5.

Lundgren JD, Allison KC, Stunkard AJ. Familial aggregation in the night eating syndrome. Int J Eat Disord. 2006 Sep;39(6):516-8. [PubMed: 16609983]

6.

McCuen-Wurst C, Ruggieri M, Allison KC. Disordered eating and obesity: associations between binge-eating disorder, night-eating syndrome, and weight-related comorbidities. Ann N Y Acad Sci. 2018 Jan;1411(1):96-105. [PMC free article: PMC5788730] [PubMed: 29044551]

7.

Rand CS, Macgregor AM, Stunkard AJ. The night eating syndrome in the general population and among postoperative obesity surgery patients. Int J Eat Disord. 1997 Jul;22(1):65-9. [PubMed: 9140737]

8.

de Zwaan M, Müller A, Allison KC, Brähler E, Hilbert A. Prevalence and correlates of night eating in the German general population. PLoS One. 2014;9(5):e97667. [PMC free article: PMC4020826] [PubMed: 24828066]

9.

Vander Wal JS. Night eating syndrome: a critical review of the literature. Clin Psychol Rev. 2012 Feb;32(1):49-59. [PubMed: 22142838]

10.

Kucukgoncu S, Midura M, Tek C. Optimal management of night eating syndrome: challenges and solutions. Neuropsychiatr Dis Treat. 2015;11:751-60. [PMC free article: PMC4371896] [PubMed: 25834450]

11.

Tholin S, Lindroos A, Tynelius P, Akerstedt T, Stunkard AJ, Bulik CM, Rasmussen F. Prevalence of night eating in obese and nonobese twins. Obesity (Silver Spring). 2009 May;17(5):1050-5. [PMC free article: PMC2923060] [PubMed: 19396084]

12.

Gallant AR, Lundgren J, Drapeau V. The night-eating syndrome and obesity. Obes Rev. 2012 Jun;13(6):528-36. [PubMed: 22222118]

13.

Marshall HM, Allison KC, O'Reardon JP, Birketvedt G, Stunkard AJ. Night eating syndrome among nonobese persons. Int J Eat Disord. 2004 Mar;35(2):217-22. [PubMed: 14994360]

14.

Napolitano MA, Head S, Babyak MA, Blumenthal JA. Binge eating disorder and night eating syndrome: psychological and behavioral characteristics. Int J Eat Disord. 2001 Sep;30(2):193-203. [PubMed: 11449453]

15.

Allison KC, Lundgren JD, Stunkard AJ, Bulik CM, Lindroos AK, Thornton LM, Rasmussen F. Validation of screening questions and symptom coherence of night eating in the Swedish Twin Registry. Compr Psychiatry. 2014 Apr;55(3):579-87. [PubMed: 24457035]

16.

Allison KC, Grilo CM, Masheb RM, Stunkard AJ. Binge eating disorder and night eating syndrome: a comparative study of disordered eating. J Consult Clin Psychol. 2005 Dec;73(6):1107-15. [PubMed: 16392984]

17.

Lundgren JD, Allison KC, Crow S, O'Reardon JP, Berg KC, Galbraith J, Martino NS, Stunkard AJ. Prevalence of the night eating syndrome in a psychiatric population. Am J Psychiatry. 2006 Jan;163(1):156-8. [PubMed: 16390906]

18.

Allison KC, Lundgren JD, O'Reardon JP, Martino NS, Sarwer DB, Wadden TA, Crosby RD, Engel SG, Stunkard AJ. The Night Eating Questionnaire (NEQ): psychometric properties of a measure of severity of the Night Eating Syndrome. Eat Behav. 2008 Jan;9(1):62-72. [PubMed: 18167324]

19.

Vinai P, Allison KC, Cardetti S, Carpegna G, Ferrato N, Masante D, Vallauri P, Ruggiero GM, Sassaroli S. Psychopathology and treatment of night eating syndrome: a review. Eat Weight Disord. 2008 Jun;13(2):54-63. [PubMed: 18612253]

20.

Sassaroli S, Ruggiero GM, Vinai P, Cardetti S, Carpegna G, Ferrato N, Vallauri P, Masante D, Scarone S, Bertelli S, Bidone R, Busetto L, Sampietro S. Daily and nightly anxiety among patients affected by night eating syndrome and binge eating disorder. Eat Disord. 2009 Mar-Apr;17(2):140-5. [PubMed: 19242843]

21.

Björntorp P, Rosmond R. Neuroendocrine abnormalities in visceral obesity. Int J Obes Relat Metab Disord. 2000 Jun;24 Suppl 2:S80-5. [PubMed: 10997616]

22.

Epel E, Lapidus R, McEwen B, Brownell K. Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior. Psychoneuroendocrinology. 2001 Jan;26(1):37-49. [PubMed: 11070333]

23.

Birketvedt GS, Florholmen J, Sundsfjord J, Osterud B, Dinges D, Bilker W, Stunkard A. Behavioral and neuroendocrine characteristics of the night-eating syndrome. JAMA. 1999 Aug 18;282(7):657-63. [PubMed: 10517719]

24.

O'Reardon JP, Ringel BL, Dinges DF, Allison KC, Rogers NL, Martino NS, Stunkard AJ. Circadian eating and sleeping patterns in the night eating syndrome. Obes Res. 2004 Nov;12(11):1789-96. [PubMed: 15601974]

25.

Stunkard AJ, Allison KC, Lundgren JD, Martino NS, Heo M, Etemad B, O'Reardon JP. A paradigm for facilitating pharmacotherapy at a distance: sertraline treatment of the night eating syndrome. J Clin Psychiatry. 2006 Oct;67(10):1568-72. [PubMed: 17107248]

26.

Gluck ME, Geliebter A, Satov T. Night eating syndrome is associated with depression, low self-esteem, reduced daytime hunger, and less weight loss in obese outpatients. Obes Res. 2001 Apr;9(4):264-7. [PubMed: 11331430]

27.

Allison KC, Engel SG, Crosby RD, de Zwaan M, O'Reardon JP, Wonderlich SA, Mitchell JE, West DS, Wadden TA, Stunkard AJ. Evaluation of diagnostic criteria for night eating syndrome using item response theory analysis. Eat Behav. 2008 Dec;9(4):398-407. [PMC free article: PMC2583783] [PubMed: 18928902]

28.

Tzischinski O, Lazer Y. [Nocturnal eating disorder--sleep or eating disorder?]. Harefuah. 2000 Feb 01;138(3):199-203, 271, 270. [PubMed: 10883092]

29.

de Zwaan M, Roerig DB, Crosby RD, Karaz S, Mitchell JE. Nighttime eating: a descriptive study. Int J Eat Disord. 2006 Apr;39(3):224-32. [PubMed: 16511835]

30.

Crow S, Kendall D, Praus B, Thuras P. Binge eating and other psychopathology in patients with type II diabetes mellitus. Int J Eat Disord. 2001 Sep;30(2):222-6. [PubMed: 11449458]

31.

Allison KC, Crow SJ, Reeves RR, West DS, Foreyt JP, Dilillo VG, Wadden TA, Jeffery RW, Van Dorsten B, Stunkard AJ. Binge eating disorder and night eating syndrome in adults with type 2 diabetes. Obesity (Silver Spring). 2007 May;15(5):1287-93. [PMC free article: PMC2753278] [PubMed: 17495205]

32.

Morse SA, Ciechanowski PS, Katon WJ, Hirsch IB. Isn't this just bedtime snacking? The potential adverse effects of night-eating symptoms on treatment adherence and outcomes in patients with diabetes. Diabetes Care. 2006 Aug;29(8):1800-4. [PubMed: 16873783]

33.

Allison KC, Lundgren JD, Moore RH, O'Reardon JP, Stunkard AJ. Cognitive behavior therapy for night eating syndrome: a pilot study. Am J Psychother. 2010;64(1):91-106. [PubMed: 20405767]

34.

Stunkard AJ, Allison KC, Lundgren JD, O'Reardon JP. A biobehavioural model of the night eating syndrome. Obes Rev. 2009 Nov;10 Suppl 2:69-77. [PubMed: 19849804]

35.

O'Reardon JP, Stunkard AJ, Allison KC. Clinical trial of sertraline in the treatment of night eating syndrome. Int J Eat Disord. 2004 Jan;35(1):16-26. [PubMed: 14705153]

36.

Allison KC, Studt SK, Berkowitz RI, Hesson LA, Moore RH, Dubroff JG, Newberg A, Stunkard AJ. An open-label efficacy trial of escitalopram for night eating syndrome. Eat Behav. 2013 Apr;14(2):199-203. [PubMed: 23557820]

37.

Vander Wal JS, Gang CH, Griffing GT, Gadde KM. Escitalopram for treatment of night eating syndrome: a 12-week, randomized, placebo-controlled trial. J Clin Psychopharmacol. 2012 Jun;32(3):341-5. [PubMed: 22544016]

38.

Vander Wal JS, Maraldo TM, Vercellone AC, Gagne DA. Education, progressive muscle relaxation therapy, and exercise for the treatment of night eating syndrome. A pilot study. Appetite. 2015 Jun;89:136-44. [PubMed: 25660340]

39.

Krysta K, Krzystanek M, Janas-Kozik M, Krupka-Matuszczyk I. Bright light therapy in the treatment of childhood and adolescence depression, antepartum depression, and eating disorders. J Neural Transm (Vienna). 2012 Oct;119(10):1167-72. [PubMed: 22806006]

40.

Friedman S, Even C, Dardennes R, Guelfi JD. Light therapy, obesity, and night-eating syndrome. Am J Psychiatry. 2002 May;159(5):875-6. [PubMed: 11986153]

41.

McCune AM, Lundgren JD. Bright light therapy for the treatment of night eating syndrome: A pilot study. Psychiatry Res. 2015 Sep 30;229(1-2):577-9. [PubMed: 26239768]

42.

Stunkard AJ, Allison KC, Geliebter A, Lundgren JD, Gluck ME, O'Reardon JP. Development of criteria for a diagnosis: lessons from the night eating syndrome. Compr Psychiatry. 2009 Sep-Oct;50(5):391-9. [PMC free article: PMC3835341] [PubMed: 19683608]

43.

Pinto TF, Silva FG, Bruin VM, Bruin PF. Night eating syndrome: How to treat it? Rev Assoc Med Bras (1992). 2016 Oct;62(7):701-707. [PubMed: 27925052]

44.

Zawilska JB, Santorek-Strumiłło EJ, Kuna P. [Nighttime eating disorders--clinical symptoms and treatment]. Przegl Lek. 2010;67(7):536-40. [PubMed: 21387771]

45.

Lundgren JD, Allison KC, O'Reardon JP, Stunkard AJ. A descriptive study of non-obese persons with night eating syndrome and a weight-matched comparison group. Eat Behav. 2008 Aug;9(3):343-51. [PMC free article: PMC2536488] [PubMed: 18549994]

46.

Striegel-Moore RH, Franko DL, Thompson D, Affenito S, May A, Kraemer HC. Exploring the typology of night eating syndrome. Int J Eat Disord. 2008 Jul;41(5):411-8. [PMC free article: PMC11622248] [PubMed: 18306340]

47.

Abbott S, Dindol N, Tahrani AA, Piya MK. Binge eating disorder and night eating syndrome in adults with type 2 diabetes: a systematic review. J Eat Disord. 2018;6:36. [PMC free article: PMC6219003] [PubMed: 30410761]

Disclosure: Ethar Salman declares no relevant financial relationships with ineligible companies.

Disclosure: Rian Kabir declares no relevant financial relationships with ineligible companies.