This revised application is submitted in response to the National Institute on Aging's Program Announcement, Malnutrition in Older Persons, and focuses on a well-defined frail, homebound elderly population. The research has five specific aims, as follow: 1) to assess the cross-sectional relationships between indicators of nutritional status, sociodemographic and related characteristics, and cognitive psychological and physical function; 2) to determine cross-sectional relationships between metabolic parameters and indicators of nutritional status; 3) to identify the nutritional and metabolic predictors of weight change over one year; 4) to identify sociodemographic and related characteristics and functional health parameters which predict prospective changes in nutritional status indicators over one year; and 5) to determine the nutritional, functional, and metabolic predictors of mortality and health outcomes over one year. The project will be carried out in 700 homebound elderly patients (mean age 80 years; range 60-101 years). The majority of these patients are extremely frail; three-quarters are female. Some 42 percent are minority individuals (primarily African Americans), and half have extremely low incomes. Most data will be collected at in-home visits by trained interviewers using standardized or validated instruments and protocols; blood samples will be drawn by experienced phlebotomists. The study patients are currently served by Boston University Geriatric Services, which includes the Boston University Home Medical Service (HMC) and the Boston City Hospital Home Care Program. HMS was established in 1875 and is the oldest program of physician home services in the United States. This study offers a unique opportunity to examine the health-related determinants and consequences of malnutrition in an existing cohort of ethnically diverse, inner-city elderly who are at high risk for major nutritional problems. The investigators state that among the particular strengths of the research are the availability of a large, well-defined study population of frail, homebound elderly; the inclusion of the oldest-old; the multidisciplinary and experienced research team; the thorough prospective investigation of nutritional status; the comprehensive evaluation of nutritional, metabolic, functional, clinical, and health outcome variables and mortality; the formulation of a limited and focused set of key hypotheses; and adequate study of power for each aim.