Albert J. Stunkard Speaks Out About Night Eating Syndrome

by Sandra Haas Binford, MAEd

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Dr. Albert Stunkard

Thanksgiving weekend in America, a national holiday when everyone thinks about eating, is an appropriate time to interview Dr. Albert Stunkard to discuss people who eat too many calories at the wrong time of day. Is such behavior an American phenomenon or the result of an underlying problem? Considering the problem of excessive calorie-consumption regardless of timing, the American obesity epidemic requires that clinicians and the public learn more about night eating syndrome.

Albert J. Stunkard, MD, Emeritus Professor and former Chair of Psychiatry at the University of Pennsylvania School of Medicine, is a pioneer in the psychiatry of eating disorders, being first to describe the powerful influence of social class on obesity, first to describe both binge eating and night eating syndromes, and author of a widely used questionnaire to assess the psychological aspects of eating behavior.(1) His awards include the Institute of Medicine's Rhoda and Bernard Sarnat International Prize(2) and the Academy of Eating Disorders Lifetime Achievement Award;(3) the Obesity Society named an award in his honor, the Mickey Stunkard Lifetime Achievement Award.(4) Yet, he says that his contribution is "reasonable but not exceptional."

Ms. Binford and Dr. Stunkard

Definition and Morbidity of Night Eating Syndrome

"I first reported it in 1955 in an 18-year-old obese woman who was overeating and gaining weight,"(5) says Dr. Stunkard. He casually characterizes night eating syndrome (NES) as eating a "negligible breakfast" and consuming 25% of total, daily caloric intake after the evening meal. He adds that specifying 25% of total daily calories may be rather conservative, so some investigators have used percentages as high as 50%.(6,7) One of his more formal definitions describes NES as consisting of "morning anorexia, evening hyperphagia, and insomnia,"(8) and the evolved, operationalized definition as of 2005 was "engaging in evening hyperphagia (consumption of ≥ 25% of total daily calories after completion of the evening meal) and/or nocturnal awakenings accompanied by ingestions of food (≥ 3 episodes/week)."(9) In fact, as we will see below, the waking component may be key to understanding the etiology, diagnosis, and treatment of NES.

Although NES is a clinically recognizable syndrome, it is described only under Eating Disorder Not Otherwise Specified (EDNOS) in the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR) of the American Psychiatric Association.(10) When asked about the likelihood of it being included as a "disorder" in the Diagnostic and Statistical Manual, Fifth Edition (DSM-5), where it is not in the published draft,(11) he says that his new and upcoming papers "might help." He adds that the American Psychiatric Association is "concerned that there are too many new diagnoses in DSM-5." His research team has recently proposed diagnostic criteria for NES(12) and he thinks it probable that NES will be included as a separate disorder in DSM-5.

Dr. Stunkard says of night eating that "wider recognition is needed" among physicians. Approximately 3.5% of women and 4.5% of men in the United States experience night eating behavior as defined above. Indeed, across many countries and continents, its prevalence is estimated at 4% to 5% of the population. Further, this behavior tends to be associated with obesity, an epidemic of increasing proportion in the United States population. In their original description of 1955, Dr. Stunkard and colleagues noted a 64% prevalence of NES among difficult-to-treat obese patients. More recent papers document that NES is common among clinically obese patients, with prevalences of 6% among those with a body mass index (BMI) > 35;(13) of 16% among 166 obese subjects in an Italian study;(14) and of 27% among patients who had undergone gastric restriction surgery;(15) among others. Because nonobese persons (BMI < 25) show similar responses on the Night Eating Questionnaire(16) to those of obese persons (BMI > 30), but are notably younger, Dr. Stunkard and his colleagues proposed in a 2004 paper that NES may contribute to the development of obesity.(17)

Many patients have sought treatment, but all too often, psychiatrists and other physicians are not recognizing the symptoms as those of night eating syndrome. "Almost none of the obese NES patients who came to me because of their obesity had had their NES recognized and they had usually been looking for help for over a year," he elaborates.

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Comorbidities and Differential Diagnosis

Night eating syndrome is not to be confused with "sleep-related eating disorder" (SRED), in which one eats while sleeping. In contrast, patients with NES awaken before eating, clarifies Dr. Stunkard. Further distinction between these syndromes is published elsewhere in the literature. Sleep-related eating disorder is also characterized by compulsive binge eating during diurnal awakenings, but exhibits night eating behaviors linked with reduced consciousness and sleep disorders, mainly somnambulism. Sleep-related eating disorder seems to be a clinical subtype of sleep disorders,(6) not an eating disorder, as NES is.

NES is also distinguished from binge eating disorder; the two conditions can be comorbid, but are different. As discussed in the recent Compass Points™ article on eating disorders (August 9, 2010),(18) binge eating disorder is characterized by the binge eating behavior seen in bulimia but without the subsequent attempts at weight loss,(19) particularly by vomiting, Dr. Stunkard adds. Bingeing involves taking in an unusually large quantity of food in a discrete time period and feeling a sense of lack of control during the episode.(10) Dr. Stunkard maintains that it is much more difficult to treat comorbid binge eating and night eating than either condition alone.

In a study of major depressive disorder (MDD) and night eating syndrome, Dr. Stunkard and colleagues published results in 2009 of serotonin transporter (SERT) binding affinity using single-photon-emission computed tomography in patients with MDD and NES. This study demonstrated that patients with NES had significantly greater SERT uptake ratios in the midbrain, right temporal lobe, and left temporal lobe regions than those with MDD, suggesting that these are distinct clinical syndromes.(20)

Other researchers have published evidence that NES and winter seasonal affective disorder (SAD) are not overlapping syndromes, although they share some features, including snacking on high-carbohydrate/high-fat food with increased weight, emotional distress, circadian disturbances, good response to serotonergic antidepressants (SSRIs), and bright-light therapy.(21)

Some patients feel a strong desire to eat in NES, but there is no evidence that night eating behaviors in NES represent obsessive compulsive disorder (OCD), Dr. Stunkard says.

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Energy Intake Timing Pattern in NES

In 1999, Dr. Stunkard and Norwegian colleagues published findings of two arms of research into the behavioral and neuroendocrine characteristics of NES. Although NES was empirically described in 1955, this later research showed through careful clinical study that night eaters experienced more than double the number of eating episodes in each 24 hours and consumed significantly more of their daily energy intake at night than did control subjects. They also awoke many more times per night, consumed food more than half of the times they awakened, and showed lower nocturnal levels of melatonin and leptin. Peak levels of the stress hormone cortisol were higher than those of controls.(22)

Dr. Stunkard says that the "need to eat is probably on a circadian rhythm." In 2004, he and his colleagues published findings indicating no difference between the total energy intake of the subjects with NES and the control subjects, but the timing pattern of energy intake differed greatly between these groups. Although subjects with NES had sleep onset, offset, and total sleep duration times comparable with those of controls, they reported more nighttime awakenings than did controls. Further, actigraphic monitoring showed that patients with NES awakened a mere 128 minutes after sleep onset, while control subjects first roused, on average, 193 minutes after onset of sleep. Subjects with NES consumed food on 74% of the awakenings, whereas no control subjects ate. The study concluded that NES may involve a dissociation of the circadian control of eating relative to sleep.(23) In 2009, his team published findings that phase delays of 1.0 hours – 2.8 hours were found in the 2 food-regulatory rhythms of leptin and insulin, as well as in the circadian rhythm of melatonin (with a trend for a delay in the circadian cortisol rhythm).(24) Further, Dr. Stunkard shares the "fairly new" finding that, in a 24-hour cycle, the circadian rhythm is delayed by 1 – 2 hours in patients with NES. Ray Boston, PhD, MSc, at the University of Pennsylvania School of Veterinary Medicine, performed the calculations in this study, which is still under review.(25)

People with NES do not feel out of control, but they do feel guilty about night eating. When they are "bogged down in guilt, they overeat and feel depressed overall, especially at night, after eating." They also exhibit rational, then irrational, thinking with regard to their nighttime eating behavior, for example:

• Rational thinking: "'If I eat, maybe I'll be able to sleep more.'"
• Irrational thinking: "If I don't get to sleep, 'curses—that's because I ate something.'"

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Treatment of Night Eating

While Dr. Stunkard's 1992 writing states that "attempts at weight reduction in the presence of [NES is] inordinately difficult and may subject the patient to unnecessary distress,"(8) he now describes a pharmacological treatment that helps patients lose weight, one that he calls "so simple." He also names cognitive behavioral therapy as a potentially useful monotherapy or adjunct to support pharmacotherapy.

Pharmacotherapy

Recommended Treatment
"We've used ... selective serotonin reuptake inhibitors (SSRIs) that restore normal circadian rhythm and neuroendocrine levels. When the rhythm is shifted back to normal, it is easier for patients to lose weight. It's gratifying that medication helps them." Dr. Stunkard states that he uses the same dosage of SSRIs as recommended for the treatment of major depressive disorder.
[Author's note: These agents are not FDA-approved for the treatment of night eating syndrome.]

This use of an SSRI was first reported in 2004 in a clinical trial of sertraline in the treatment of night eating syndrome.(26) In a later, randomized, placebo-controlled trial of sertraline, twelve subjects in the sertraline group (71%) were classified as having responded with a "much or very much improved" in the Clinical Global Impression (CGI)(27) rating of at least 2, whereas only three subjects (18%) in the placebo group showed such response. There were also significant improvements in night eating symptoms, CGI severity ratings, quality-of-life ratings, frequency of nocturnal ingestions and awakenings, and caloric intake after the evening meal. Overweight and obese subjects in the treatment group lost a significant amount of weight by week 8.(28) This treatment was further tested through a telemedicine paradigm, in which SSRI pharmacotherapy obtained results similar to those reported earlier and facilitated specialty consultation to personal physicians of 50 study participants.(29)

Typical Treatment
Here lies the crux of the problem: "Doctors do not know what to do with NES. They figure, if they can help their patients sleep, then the patients will not be awake and eating during the night. The former practice of giving hypnotics or sleeping pills has fallen out of favor. However, while these agents were in use, instead of helping, they might have caused patients to become disorganized and eat even more." Dr. Stunkard states, "When doctors treat with hypnotics, it doesn't help and it may make the condition worse. NES responds well to SSRIs," as noted above.(26,28,29)

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Nonpharmacological Therapy

Cognitive-Behavioral Therapy
Cognitive-behavioral therapy (CBT) has demonstrated promising results and should be explored further through a controlled treatment trial. The 2010 pilot study into CBT for night eating showed significant improvements in the core aspects of NES and weight reduction. Specifically, the pilot study showed significant decreases in caloric intake after dinner, number of nocturnal ingestions, weight, and score on the Night Eating Symptom Scale(30) and the Night Eating Questionnaire.(16) Therefore, CBT may be sufficient treatment of NES in its own right, but further studies are needed.

Dr. Stunkard states, "Patients often feel so 'down in the dumps' that even with SSRI treatment, they still worry whether the freedom from NES will remain stable." This worry may occur even when they have only a thought of night eating but do not follow through with the behavior. "CBT encourages patients to have faith in themselves that they are not at the mercy of impulses." Further, "it helps to talk to them to improve optimism that treatment works."

Light Therapy
When asked about other nonpharmacological therapy for NES, Dr. Stunkard immediately mentioned investigations into changing lighting, although this treatment is "still in its infancy." In the 2009 paper on circadian rhythm profiles in NES, his team proposed that NES may result from dissociations between central (suprachiasmatic nucleus) timing mechanisms and putative oscillators elsewhere in the central nervous system or periphery, such as in the stomach or liver. The authors suggest that bright-light therapy may be useful as a chronobiologic treatment for NES—noting that it has shown efficacy in reducing night eating in case studies—and that it should be evaluated in controlled clinical trials.(24)

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Summary

Dr. Stunkard describes his team's latest, unpublished finding that, in a 24-hour cycle, the circadian rhythm is delayed by 1 – 2 hours in patients with NES. Clinicians who carefully question their patients about sleeping and eating habits during the night are most likely to recognize night eating syndrome. He recommends asking these three questions:

1. "What time do you usually get to sleep?"
2. "If you wake up after you are asleep, how easy is it to fall asleep again?"
3. "Does eating make it easier to get back to sleep?"

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Clinical Connections

1. Knowledge: The clinician should improve recognition of night eating syndrome (NES) as a serious medical problem and one that is common among obese persons.
2. Competence: The clinician should assess night eating syndrome as a circadian rhythm problem.
3. Performance: The clinician should:
1. Take a careful, detailed eating history and intake assessment that includes nighttime habits, asking the three questions noted above. "It makes the syndrome more obvious if the patient is waking up to eat."
2. Consider treatment with a selective serotonin reuptake inhibitor (SSRI) based on current evidence for treating NES,(26,27,29) instead of prescribing a sleeping aid.
   [Author's note: These agents are not FDA-approved for the treatment of night eating syndrome.]
4. Patient Outcomes: The patient must have clinical follow-up and understand the purpose of treatment. Cognitive behavioral therapy may be sufficient treatment by itself and may improve results of other treatment. Appropriately treated patients should experience resolution of their night eating behavior.

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Obesity continues to be a significant public health problem. Visit www.cmeoutfitters.com/CC522 to participate in the online activity Obesity, Diabetes and Diet: Combining Evidence for All Three into Improved Patient Care for additional information and resources to manage this chronic illness.

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References

1. The Albert J. Stunkard Weight Management Program. University of Pennsylvania Almanac 2007;54:1,3. Available at: http://www.upenn.edu/almanac/volumes/v54/n07/stunkard.html. Accessed on December 6, 2010.
2. Albert J. Stunkard, MD, Receives Prestigious Award from the Institute of Medicine [press release]. University of Pennsylvania Health System Web site. Available at: http://www.uphs.upenn.edu/news/News_Releases/nov04/StunkardIOMaward.htm. Posted on November 30, 2004. Accessed on December 6, 2010.
3. Academy for Eating Disorders. Program of the 2010 International Conference on Eating Disorders; June 10 – 12, 2010; Salzburg, Austria. Available at: http://www.aedweb.org/AM/Template.cfm?Section=ICED_Homepage&Template=/ CM/ContentDisplay.cfm&ContentID=1961. Accessed December 6, 2010.
4. The Obesity Society. 2009 Award Winners. Available at: http://www.obesity.org/obesity2010/pdf/2009_Award_Winners.pdf. Accessed December 6, 2010.
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9. Lundgren JD, Allison KC, O'Reardon JP, et al. A descriptive study of non-obese persons with night eating syndrome and a weight-matched comparison group. Eat Behav 2008;9:343-351.
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24. Goel N, Stunkard AJ, Rogers NL, et al. Circadian rhythm profiles in women with night eating syndrome. J Biol Rhythms 2009;24:85-94.
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26. O'Reardon JP, Stunkard AJ, Allison KC. Clinical trial of sertraline in the treatment of night eating syndrome. Int J Eat Disord 2004;35:16-26.
27. Guy W. ECDEU Assessment Manual for Psychopharmacology—Revised (DHEW Publ No ADM 76-338). Rockville, MD: U.S. Department of Health, Education, and Welfare; 1976, pp. 218–222.
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29. Stunkard AJ, Allison KC, Lundgren JD, et al. A paradigm for facilitating pharmacotherapy at a distance: sertraline treatment of the night eating syndrome. J Clin Psychiatry 2006;67:1568-1572.
30. Allison KC, Lundgren JD, Moore RH, et al. Cognitive behavior therapy for night eating syndrome: a pilot study. Am J Psychother 2010;64:91-106.
31. Root TL, Thornton LM, Lindroos AK, et al. Shared and unique genetic and environmental influences on binge eating and night eating: a Swedish twin study. Eat Behav 2010;11:92-98.

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