A nutritional study of 100 patients enrolled in an active geriatric outpatient teaching program was conducted to document the clinical impression of weight loss in Alzheimer's disease. All new patients were asked to complete a questionnaire on nutrition. Patients were evaluated by a geriatrician, then categorized using DSM-III and NINCDS-ADRDA criteria. There were 34 Alzheimer patients and 60 nondemented patients with an average weight of 56.2 kgs and 66.1 kgs, respectively (p less than .002). Of the Alzheimer group, 44% reported weight loss in the past five years compared with 37% of the nondemented group, despite a concomitant increase in food intake in 35% versus 7%, respectively. On a one-year follow-up, 92% of Alzheimer patients lost weight, whereas 57% of the nondemented patients actually gained weight. The increase in reported food intake, with a significant concomitant weight loss, raises some challenging questions as to the existence of a hypermetabolic state in Alzheimer's disease.