Clinical validity of the descriptor. "presence of a belief that one must eat in order to get to sleep" in diagnosing the Night Eating Syndrome.

The diagnostic criteria for the Night Eating Syndrome (NES) published in 2010 require the presence of two core criteria: evening hyperphagia and/or nocturnal awakenings for ingestion of food and three of five diagnostic descriptors. One of the descriptors is as follows: "The belief that one must eat in order to fall asleep". In this study we evaluated whether this conviction is significantly more prominent in obese individuals suffering from insomnia and nocturnal eating, than among obese patients with insomnia who do not eat at night. Ninety-eight obese subjects afflicted by insomnia were included in this study. Eight were affected by NES, 33 by Binge Eating Disorder (BED), and 13 by both BED and NES. Subjects' insomnia and sleep disturbances were assessed using the Insomnia Severity Index and the Sleep Disturbance Questionnaire. The presence of the belief that one must eat at night in order to sleep was evaluated with the question: "Do you need to eat in order to get back to sleep when you wake up at night?" Patients affected by NES and by both BED and NES were convinced that nocturnal food intake was necessary in order to fall back asleep after a night time awakening. The presence of this belief seemed to be a critical factor in identifying the presence of the Night Eating Syndrome among obese subjects suffering from insomnia.