sign in sign up
<<
Home , Disordered eating, Night eating syndrome

CONTINUING EDUCATION

2.0 CE Contact Hours See text on pp. 222–223

■ Ann B. Townsend, MSN, RN, APN,C

Night eating syndrome (NES), an that has been linked to , was first described in 1955. It occurs when the normally synchronous patterns of energy intake and become disrupted; the result of this dysynchrony is a relative phase delay between the patterns and the normal sleep-wake cycles. Although specific criteria for NES have not yet been validated, the characteristic associated behaviors are evening hyperphagia, morning , and . This article reviews NES prevalence, behavioral and neurohormonal manifestations of this disorder, criteria for its differential diagnosis, and current treatment options. KEY WORDS: eating disorder, night eating syndrome, nocturnal eating, obesity Holist Nurs Pract 2007;21(5):217–221

Two eating disorders have been linked to obesity: cycles are not disturbed but there is a relative delay disorder (BED) and night eating syndrome of 2 to 6 hours between the eating patterns and sleep 3 (NES). The purpose of this article is to define NES, rhythms. Therefore, insomnia, sleep onset and sleep provide criteria for its diagnosis, describe its prevalence, maintenance, is characteristically associated with NES. and review pertinent research related to self-regulatory Although about half of the night awakenings in NES modalities used for treatment of this disorder. are associated with food intake, bingeing does not occur. The NES pattern of food intake is associated with the consumption of only about 30% of the daily energy intake occurring before 6:00 PM, with a rapid increase DEFINITION in food consumption during the hours of 10:00 PM until 6:00 AM. These night snacks are of a moderate size The NES was first described in 1955 by Stunkard (271 kcal) but consist of a high-carbohydrate content as an eating disorder that is characterized by morning and a high carbohydrate-to-protein nutrient ratio.1 anorexia, evening or nocturnal hyperphagia in Provisional criteria for NES includes morning a fully conscious state, and insomnia.1 It often occurs anorexia, evening hyperphagia (>50% of consumed during periods of stress and results in obesity with daily energy intake occurs after the evening meal), poor weight reduction efforts.2 The NES, recognized awakenings at least once a night, consumption of as a combination of a mood disorder, a , snacks during awakenings, and repetition of criteria and an eating disorder, is associated with a circadian for 3 months or more, and these individuals do not pattern delay in eating that results in disrupted meet criteria for or BED.2 However, sleep patterns1,3 Circadian rhythm control is directed the criteria for NES have been modified several times by the suprachiasmatic nucleus of the hypothalamus, and have not yet been validated; therefore, it is an area of the brain that may be responsible for NES currently diagnosed as an eating disorder, not symptoms.4 With NES, the biological rhythms of eating otherwise specified in the and sleep are dissociated with the primary circadian Diagnostic and Statistical of the American disruption occurring as a delay of energy intake; that Manual of Mental Disorders Psychological Association.5,6 is, eating is suppressed in the morning and increased in the evening and night. However, the circadian sleep PREVALENCE Author Affiliation: Heart Failure Center, Our Lady of Lourdes Medical Prevalence of NES in the general population is 1.5%; Center, Camden, New Jersey. however, it increases with increasing weight. In Corresponding Author: Ann B. Townsend, MSN, RN, APN,C, Heart Fail- ure Center, Our Lady of Lourdes Medical Center, 1600 Haddon Ave, Cam- obesity clinics, the prevalence increases to 10%, and den, NJ 08103 ([email protected]). in individuals undergoing bariatric surgery, the

217 218 HOLISTIC NURSING PRACTICE • SEPTEMBER/OCTOBER 2007 prevalence is as high as 25%.1 Although NES does 1 week. Behaviorally, Birketvedt et al2 demonstrated occur in nonobese individuals, it is more common in differences in the patterns of diurnal eating between obese people, especially those seeking weight loss the groups, although the daily amount of food intake treatment.2 It is most prevalent in severely obese differed only moderately. Night eaters consumed 56% men.7 In addition, an early age at onset of this disorder of their total energy intake between 8:00 PM and has been associated with a chronic course.5 6:00 AM, whereas the control group participants The prevalence and demographic correlates of NES consumed only 15% of their total energy intake during were examined using data from 2 national surveys, the the same period. The content of the food eaten during National Health and Nutrition Examination Survey III the night demonstrated higher carbohydrate content and the Continuing Survey of Food Intakes by (70.3%) than the 46.6% content of foods consumed Individuals.8 The results of these 2 surveys similarly during the day.2 Finally, after 4:00 PM, the mood of the demonstrated that night eating is most common during night eaters fell hourly in comparison with the control the weekend, with prevalence estimates that varied by group, whose mood remained unchanged. age group. Adolescents most often met the criteria for During the neuroendocrine portion of the study, night eating, whereas the elderly were among the least plasma , , insulin, blood glucose, and likely to meet NES criteria. In National Health and cortisol levels were measured during a 24-hour period. Nutrition Examination Survey data, men were more Cortisol, leptin, and melatonin are regulatory likely than women and black Americans more likely hormones with circadian rhythm patterns that regulate than other ethnicities to exhibit night eating.8 The physiological and metabolic functions.10 Individuals researchers suggested that some variation between with NES demonstrated a reduction of the usual surveys could be attributed to differences in symptom nocturnal rise in plasma melatonin and leptin levels, criteria for NES diagnosis or may have been the result and had higher plasma cortisol levels than controls.2 It of social and cultural affects on eating patterns. is during the normal nocturnal rise of melatonin that sleep is initiated; subsequently, melatonin continues to be produced proportionally to the length of 11 BEHAVIORAL CHARACTERISTICS AND darkness. Melatonin, produced rhythmically from NEUROENDOCRINE PATTERNS the pineal gland, is suppressed during stress by corticotropin-releasing factor. Cortisol, also released In the past, individuals with obesity have been in response to chronic stress, makes the body less considered a homogenous group; however, sensitive to leptin. Leptin is a protein hormone behaviorally, there is considerable variability within secreted from adipose tissue that signals the brain of this population.9 Two of these subcategories, BED and satiety, suppresses appetite, and helps to maintain NES, have been investigated for mood and eating sleep.11 Leptin levels were found to be higher among behavior differences and similarities.9 The NES, the night eaters than normal weight night less studied of the 2 disorders, has had continued eaters. Blood glucose and insulin levels were modification of its descriptive and diagnostic criteria consistent between the groups.2 On the basis of these since its first description by Stunkard in 1955. findings, the researchers concluded that night eating Initially, morning anorexia, evening hyperphagia, occurred in NES, an eating disorder, to restore sleep emotional distress, and insomnia were characteristics patterns. Through the ingestion of carbohydrate-rich of the disorder.9 In 1996, the consumption of more night snacks, night eaters may increase the availability than 50% of calories after 7:00 PM was added to these of tryptophan, and thus promote sleep.2 criteria. Later, sleep disturbance and evening tension To evaluate the interaction between the biological or distress were included.9 However, the core circadian rhythm patterns of leptin and melatonin with behavioral symptom of NES remains night eating.8 the stress-related biological responses of the Birketvedt et al2 studied behavioral and hypothalamic-pituitary-adrenal axis, Birketvedt et al10 neuroendocrine characteristics of NES. The behavioral investigated the neuroendocrine patterns of 5 females observation part of the study, which consisted of 10 with NES. In comparison with matched controls, obese participants and 10 matched controls, was individuals with NES demonstrated a disturbance in conducted at an outpatient weight and eating disorders the response of the hypothalamic-pituitary-adrenal clinic. The timing of energy intake, mood level, and axis as well as attenuation of corticotropin and cortisol sleep disturbances of the participants was assessed for response as a result of a stimulation dose of Night Eating Syndrome 219 intravenous corticotropin-releasing hormone.10 levels of anxiety than other obese individuals.9 The Although the sample was small (N = 10), the results of this study also demonstrated that individuals researchers concluded that NES is associated with an with NES had an earlier onset of obesity than attenuated corticotropin response as reflected by individuals with no eating disorder diagnosis. The elevated cortisol levels that disrupt sleep and appetite researchers suggested that these findings may indicate patterns.10 These responses may explain the circadian that individuals with both NES and BED experience alterations of melatonin and leptin associated with greater psychological distress as a result of a NES and the subsequent behavior manifestations of prolonged struggle with weight issues and may use this disorder.10 eating as a coping method.9 Recently, Allison et al12 evaluated the In addition to BED, 2 primary sleep disorders, appetite-regulating hormones between individuals nocturnal sleep-related eating disorder and nocturnal with NES (n = 15) and a matched control group (n = eating/drinking syndrome, are differential diagnoses to 14). Although the total energy intake did not differ consider with NES. The nocturnal sleep-related eating between the groups, the NES group ate more at night. disorder is associated with somnambulism about 80% Ghrelin, which increases before meals in normal of the time; therefore, unlike NES, there is a lack of persons and is suppressed by eating, was found to be awareness of the nocturnal eating and amnesia for the lower in individuals with NES in the early morning event the next day.5 The second disorder to consider in hours.12 The lower ghrelin levels associated with night the differential diagnosis of NES, nocturnal awakenings in the NES group suggested that the food eating/drinking syndrome, is characterized as a sleep ingestions suppressed ghrelin, and in the NES, the disorder with recurrent awakenings; however, the lower ghrelin levels were a consequence not a cause of individual is unable to return to sleep without eating or NES.12 In addition, insulin levels were significantly drinking. In contrast to nocturnal sleep-related eating higher and glucose levels were marginally elevated in disorder, the individual does maintain full awareness the NES group than in the control group. The during the event and has no associated amnesia researchers concluded that these neurohormonal following the awakening. differences in NES occurred as a result of alterations in food timing and not as a result of night eating.12 TREATMENT AND SELF-REGULATION

DIFFERENTIAL DIAGNOSES Treatment of NES has not been extensively reported in the literature. In one trial of relaxation therapy, In contrast to NES, BED has been considerably abbreviated progressive muscle relaxation technique researched with specific diagnostic characteristics that (APRT) was evaluated as an intervention on a group of include (a) consumption of large amounts of food in a 20 adults with NES.13 In this study, participants were discrete time frame; (b) a lack of control regarding randomly assigned to a relaxation-training group with food consumption during this period; and (c) a lack of APRT (n = 10) or a control group (n = 10). compensatory behavior after the binge period.9 In a Individuals were assessed presessions and study that examined the psychological and behavioral postsessions for stress, anxiety, relaxation, and characteristics of NES and BED, participants from an salivary cortisol. Mood, food diaries, and hunger outpatient university-based weight loss center were ratings were also evaluated. The results of this study recruited.9 The 41 females and 42 males enrolled in demonstrated that after 1 week of 20-minute APRT this study were classified into 4 groups that consisted sessions, the individuals with NES assigned to this of NES only (n = 23), BED only (n = 13), both NES group reported increased relaxation, decreased and BED (n = 13), or no diagnosis of an eating anxiety, and reduced stress levels.13 This reported disorder (n = 34). The NES group scored significantly increase in relaxation and reduction in stress and lower on anxiety than either the BED group or the anxiety levels was accompanied by reduced levels of group with both NES and BED; the NES and BED salivary cortisol on day 1 of the intervention. In combination group had the highest body mass index addition, the APRT group participants reported higher levels and the highest anxiety scores among the morning hunger and were more likely to eat breakfast; 4 groups. This finding is contradictory to previous in the evening, lower hunger was reported and less findings that individuals with NES experience higher eating occurred at night in the APRT group.13 220 HOLISTIC NURSING PRACTICE • SEPTEMBER/OCTOBER 2007

Stunkard et al3 reported that 23 night eaters daylight and has stimulating effects. Bright light described a total of 83 medications that they therapy improved the symptoms of NES in an open considered beneficial with the following results study of an obese subject despite comorbid depressive reported: (a) 2 of the 25 reported use of symptoms.16 In this case study, a 51-year-old women antidepressants was considered as moderately with a body mass index of 31.2 kg and a nonseasonal effective therapy; (b) none of the 16 reports on major depressive disorder was diagnosed with NES on hypnotics was considered effective; (c) 23 reported the basis of the following criteria: morning anorexia, use of herbal preparations, with 3 indicating benefit evening hyperphagia, and nocturnal awakenings with from kava-kava, 2 reporting benefits with melatonin, consumption of snacks (high-carbohydrate content of and 2 specifying valerian root as helpful; and (d)4 67.8% and a high carbohydrate-to-protein ratio of individuals reported effectiveness using fenfluramine 6:1). In addition to ongoing pharmacologic therapy and phentermine (fen-phen). In an open-label trial, 17 with a selective serotonin reuptake inhibitor of these individuals participated in a 12-week course (paroxetine 40 mg daily), 14 morning sessions of 10 of sertraline, a selective serotonin reuptake inhibitor, 000 lux white light for 30 minutes daily were added. as a medication for the treatment of NES.3 Twelve At the conclusion of these sessions, the patient no participants completed the trial with improved longer met diagnostic criteria for depression or NES.16 outcome measures for night awakenings (P < .01), However, 1 month after the light therapy concluded, nocturnal ingestions (P < .01), and reduced energy her NES symptoms had returned, although she was not intake after supper (P < .01). The researchers depressed. Another series of 12 morning light sessions concluded that NES may be appropriately treated with was then commenced and her NES symptoms were serotonin reuptake inhibitors, however, randomized again suppressed. controlled trials are needed.3 A second case study was reported using light In 2006, O’Reardon et al14 conducted the first therapy in a nonobese male with nonseasonal randomized placebo-controlled trial to evaluate the depression and NES.17 After 14 consecutive efficacy of sertraline in the treatment of NES. In this treatments of light therapy (10 000 lux for 30 8-week double-blind study, groups were randomly minutes), both NES and depressive symptoms assigned to a flexible dose (50–200 mg) sertraline improved. The researchers suggested that NES may be group (n = 17) or placebo group (n = 17). The results associated with depression in nonobese individuals of this study indicated that sertraline effectively and that it may be a predictor for the efficacy of light reduced the symptoms of NES in 71% of the sertraline therapy when these disorders occur concomitantly. group participants. The suprachiasmatic nucleus, the circadian rhythm pacemaker, is affected by serotonergic neuron input and sertraline may restore 14 energy intake patterns in individuals with NES. SUMMARY Chromotherapy, a treatment method that uses the visible spectrum of electromagnetic radiation, has Although NES was first described more than 50 years been reportedly used in a limited number of case ago, there is still much that is unknown about the studies for the treatment of NES. It is based on the defining behavioral characteristics, neurohormonal principles that the body is composed of colors that are responses, and treatment of this syndrome. The NES, a responsible for the function of various systems in the combination of eating disorder, sleep disorder, and body.15 Bright white full-spectrum light was first used mood disorder, has been linked to chronic obesity with during the 1950s for the successful treatment of poor efforts at weight loss. Individuals often present, neonatal jaundice and is still used today for the particularly in the outpatient setting, with at least one treatment of some cancers, seasonal affective disorder, of these disorders. Therefore, the knowledge of NES bulimia nervosa, insomnia, , and drug and may provide a link to associate these otherwise alcohol dependencies.15 Melatonin, a light-responsive independent disorders of sleep, obesity, and mood chemical pathway for the synchronization of circadian disturbance. In practice, screening an obese person for rhythms and seasonal variations, is produced during underlying causes of obesity, food patterns, and darkness. It has a depressant effect and is associated sleep-wake cycles can provide valuable clues as to the with induction and maintenance of sleep. In contrast, etiology of the excess weight, and ultimately informed the neurotransmitter serotonin is produced during treatment. Night Eating Syndrome 221

REFERENCES behavioral characteristics. Int J Eat Disord. 2001;30:193– 203. 1. Stunkard AJ. Eating Disorders and Obesity A Comprehensive Hand- 10. Birketvedt GS, Sundsfjord J, Florholmen JR. Hypothalamic-pituitary- book. 2nd ed. New York: Guilford Press; 2002. adrenal axis in the night eating syndrome. Am J Physiol Endocrinol 2. Birketvedt GS, Florholmen JR, Sundsfjord J, et al. Behavioral and Metab. 2002;282:366–369. neuroendocrine characteristics of the night-eating syndrome. JAMA. 11. Qin L, Li J, Wang Y, Wang J, Xu J, Kaneko T. The effects of noc- 1999;282(7):657–663. turnal life on endocrine circadian patterns in healthy adults. Life Sci. 3. Stunkard AJ, Allison KC, O’Reardon JP. The night eating syndrome: a 2003;73:2467–2475. progress report. Appetite. 2005;45(2):182–186. 12. Allison KC, Grilo CM, Masheb RM, Stunkard AJ. 4. O’Reardon JP, Ringel BL, Dinges DF, et al. Circadian eating and sleep- and night eating syndrome: a comparative study of disordered eating. J ing patterns in the night eating syndrome. Obes Res. 2004;12(11):1789– Consult Clin Psychol. 2005;73(6):1107–1115. 1796. 13. Pawlow LA, O’Neil PM, Malcolm RJ. Night eating syndrome: effects 5. deZwaan M, Burgard ME, Schenck CH, Mitchell JE. Night time eat- of brief relaxation training on stress, mood, hunger, and eating patterns. ing: a review of the literature. Eur Eat Disord Rev. 2003;11(1):7– Int J Obes. 2003;27:970–978. 24. 14. O’Reardon JP,Allison KC, Martino NS, Lundgren JD, Heo M, Stunkard 6. Tanofsky-Kraff M, Yanovski SZ. Eating disorder or disordered eat- AJ. A randomized, placebo-controlled trial of sertraline in the treatment ing? Non-normative eating patterns in obese individuals. Obes Res. of night eating syndrome. Am J . 2006;163(5):893–899. 2004;12(9):1361–136. 15. Azeemi ST, Raza SM. A critical analysis of chromotherapy and its sci- 7. Geliebter A. New developments in binge eating disorder and the night entific evolution. Evid Based Complement Altern Med. 2005;2(4):481– eating syndrome. Appetite. 2002;39:175–177. 488. 8. Striegel-Moore RH, Franko DL, Thompson D, Affenito S, Kraemer 16. Friedman S, Even C, Dardennes R, Guelfi J. Light therapy, obesity, and HC. Night eating: prevalence and demographic correlates. Obesity. night-eating syndrome. Am J Psychiatry, 2002;159(5):875–876. 2006;14(1):139–147. 17. Friedman S, Even C, Dardennes R, Guelfi J. Light therapy, non- 9. Napolitano M, Head S, Babyak M, Blumenthal J. Binge eat- seasonal depression, and night eating syndrome. Can J Psychiatry. ing disorder and night eating syndrome: psychological and 2004;49(11):790.