Night Eating Syndrome - Brief Article

Nutrition Research Newsletter, August, 2001 by M. Gluck, A. Geliebter, T. Satov

Night eating syndrome (NES) has been characterized to include morning anorexia, evening hyperphagia, and sleep disturbances. Only a few papers have been published on night eating in the past several years. The reported prevalence of NES varies and seems to increase with severity of obesity. NES has been associated with a number of situations, including life stress, depression, and adverse reactions to weight loss. The present study investigated the prevalence of NES in a group of obese outpatients in relation to psychological measures of depression and self-esteem. They also examined daytime hunger and test-meal intake as well as weight loss after treatment.

Overweight participants were recruited through local advertisements for participation in an outpatient weight loss program at the New York Obesity Research Center of St. Luke's/ Roosevelt Hospital. A physical examination including medical history, electrocardiogram, and blood tests was performed to ensure otherwise good health, and those working either night or evening shifts were excluded from the study.

Participants were classified as having NES if they reported: (1) skipping breakfast [is greater than] 4 d/week, which was interpreted as morning anorexia; (2) consuming [is greater than] 50% of their total daily calories after 7 pm; and (3) difficulty falling asleep or staying asleep. The final sample (n=76) consisted of 53 women and 23 men with ages ranging from 22 to 60 years. A total of 11 participants (14%) met criteria for NES.

After an 8-hr fast, participants arrived at the laboratory to complete a battery of psychological tests and receive the liquid test meal (Sustacal, Mead Johnson). The flavor used was the one preferred by the participant from a previous taste rating of three flavors. They were instructed to ingest the test meal until they felt extremely full and were told not to consume any other food for 5 hours. On the day after the test meal, participants began the weight loss program. The program was based on a 900-kcal, medically supervised liquid formula diet (Pro Cal 100; R-Kane). Participants attended weekly nutritional counseling sessions and their weight was recorded. Four participants with NES and 39 normals adhered to the formula diet and remained in the study at least 1 month.

Night eaters scored significantly higher on depression, although none of the participants had severe or extreme depression. Night eaters also had significantly lower self-esteem than non-night eaters. Night eaters reported significantly less hunger and a trend toward greater fullness before the daytime test meal. After the test meal, there were no group differences in hunger or fullness ratings. Night eaters had a significantly smaller change in hunger rating after the test meal compared with normals but did not differ in change of fullness ratings. Despite feeling less hungry and more full, the nigh eaters' test-meal intake did not differ significantly from normals.

After controlling for BMI, it was revealed that the night eaters lost less weight than the non-night eaten, despite being given the same formula diet. The night eaten apparently did not comply as well and may have strayed by overeating at night. The fact that night eaters felt less hungry, yet consumed a similar test-meal intake, with a smaller change in hunger ratings afterward, might represent a general tendency to overeat. These findings support the relationship between the prevalence of NES and severity of obesity. NES is clearly a syndrome with distinct features such as greater depression, lower self-esteem, and increased meal intake later in the day. According to the researchers, NES deserves consideration as a legitimate eating disorder in the Diagnostic and Statistical Manual of Mental Disorders.

M. Gluck, A. Geliebter, T. Satov. Night Eating Syndrome Is Associated with Depression, Low-Self Esteem, Reduced Daytime Hunger, and Less Weight Loss in Obese Outpatients. Obes Res 9(4):264-267 (April 2001) [Correspondence: Marci Gluck, Ph.D., New York Obesity Research Center, Department of Medicine, St. Luke's/Roosevelt Hospital Center, New York, NY 10025. E-mail: marci513@aol.com].