Night Eating Syndrome

Night eating syndrome (NES) is conceptualized as a circadian disorder, manifested by a delay in the daily intake of food. Persons with NES must report evening hyperphagia (consuming at least 25 percent of the total daily calories after the evening meal) and/or nocturnal awakenings with ingestions of food (three or more episodes per week). Associated characteristics include morning anorexia (fasting or undereating), insomnia, depressed mood, and life stress.

Most persons with NES feel a compulsion to eat before bed and during nocturnal awakenings to help return them to sleep.

The prevalence of NES increases with adiposity and with psychiatric comorbidity. Prevalence studies have found rates of 1.5 percent in the general population, 9 to 14 percent in obesity treatment clinics, 4 percent in an older type 2 diabetic population, and 12 percent in outpatient psychiatric clinics. The breakdown of NES among males and females and non-Hispanic white and black participants does not differ from the distribution of these demographics in the samples of recent prevalence studies.

Assessment of NES

The Night Eating Questionnaire (NEQ) is a 14-item self-report inventory which assesses the pattern and timing of food intake, hunger and cravings for food, and mood and sleep difficulties. A score of 30 or greater has a positive predictive value of 73 to 77 percent. The Night Eating Syndrome History and Inventory (an unpublished structured clinical interview) provides a more thorough assessment of NES; it is available from the authors. In addition, food records noting the time, type, and amount of food consumed throughout the day and night is invaluable in both diagnosing and treating NES.

Treatment of NES

The increased research interest in NES over the past decade has led to some promising therapies. Three studies have found that the serotonin reuptake inhibitor (SSRI) sertraline significantly reduces evening [Page 503]hyperphagia, nighttime awakenings, and nocturnal ingestions of food, as well as body weight.

Cognitive behavioral therapy has also shown promise for treating NES. In a pilot study, patients have shown a benefit, including a weight loss of six pounds for completers, comparable to that seen with sertraline. The combination of pharmacotherapy and psychotherapy has not been tested but may prove useful in the future.

Investigators have also reported some success with progressive muscle relaxation, topiramate, paroxetine, and light therapy. Further research is necessary to confirm these findings, and to determine whether behavioral weight loss treatment would be effective for reducing weight and NES.

Differential Diagnosis

NES should be differentiated from binge eating disorder (BED) and sleep-related eating disorder (SRED). The main aspect of NES is the delay in the timing of eating. Most persons with NES feel a compulsion to eat before bed and during nocturnal awakenings to help return them to sleep. However, the amount of food that they eat is usually not as large as a binge; the average nocturnal ingestion is 300 to 400 calories. In contrast, the hallmark feature of BED is the consumption of a large amount of food at one sitting, often 2,000 or more calories. Also, with BED, binges do not generally take place during nighttime awakenings, although they may take place in the evening.

...