The aims of this study are: 1) to test whether total daily energy expenditure, resting metabolic rate and physical activity are higher in Alzheimer patients compared to normal elderly after controlling for differences in body composition and 2) to use the data collected to develop and cross-validate new models to predict energy requirements derived from biological markers of total daily energy expenditure in Alzheimer's patients and normal elderly and compare them to current energy recommendations. Data analysis was performed on subjects seen in previous years on this subproject.