Ten adult subjects were referred to our sleep disorders center complaining of difficulty in maintaining sleep due to frequent and recurrent awakenings to eat or drink. All patients manifested more than one episode per night, characterized by compulsive food seeking and a return to sleep only after adequate food intake. Food-seeking drive was described as an urgent abnormal need to swallow food and was associated with an absence of real hunger. Six subjects showed an elective nighttime intake of carbohydrates, and in all cases only edible substances were injected. The patients were always fully awake during the episodes and could clearly recall them in the morning. Polysomnographic investigation showed low levels of sleep efficiency, a high number of awakenings and a strict relation between nocturnal eating episodes and nonrapid eye movement (NREM) sleep. The average length of each episode was 3.5 minutes. The "eating latency", that is the interval between awakening and chewing start, was shorter than 30 seconds in 50\% of the episodes. No medical, hormonal or neurological disorders were found during clinical and laboratory investigations. Body mass index was abnormally high in six patients. Anorexia nervosa and bulimia were carefully excluded. Various psychiatric disturbances were found in nine subjects, who were nevertheless well-functioning adults. Concurrent dyssomniac disorders, such as narcolepsy or periodic leg movements occasionally associated with restless legs syndrome, were diagnosed in five patients.(ABSTRACT TRUNCATED AT 250 WORDS)