In more than 10,000 elderly persons, the mean prevalence of malnutrition is 1% in community-healthy elderly persons, 4% in outpatients receiving home care, 5% in patients with Alzheimer's disease living at home, 20% in hospitalized patients, and 37% in institutionalized elderly persons. In community-dwelling elderly persons, the MNA detects risk of malnutrition and life-style characteristics associated with nutritional risk while albumin levels and the BMI are still in the normal range. In outpatients and in hospitalized patients, the MNA is predictive of outcome and cost of care. In home care patients and nursing home residents, the MNA is related to living conditions, meal patterns, and chronic medical conditions and allows targeted intervention. The MNA has been used successfully in follow-up evaluation of outcome, nutritional intervention, nutritional education programs, and physical intervention programs in elderly persons. The MNA-SF allows quick screening to determine a person's risk of malnutrition. Early detection of malnutrition is important to allow targeted nutritional intervention and should be a key component of the geriatric assessment. The MNA test is a simple, noninvasive, well-validated screening tool for malnutrition in elderly persons and is recommended for early detection of risk of malnutrition. The MNA, as a two-step procedure (screening with the MNA-SF followed by assessment, if needed, by the full MNA), is reliable and can be easily administered by general practitioners and by health professionals at hospital or nursing home admission for early detection of risks of malnutrition. The MNA has the following characteristics: * The MNA is a two step procedure: (1) the MNA-SF to screen for malnutrition and risk of mainutrition; (2) assessment of nutritional status with the full MNA. * The MNA is an 18-item questionnaire comprising anthropometric measurements (BMI, mid-arm and calf circumference, and weight loss) combined with a questionnaire regarding dietary intake (number of meals consumed, food and fluid intake, and feeding autonomy), a global assessment (lifestyle, medication, mobility, presence of acute stress, and presence of dementia or depression), and a self-assessment (self-perception of health and nutrition). The MNA-SF comprises 6 items from the 18. * The MNA is well validated. It correlates highly with clinical assessment and objective indicators of nutritional status (albumin level, BMI, energy intake, and vitamin status). * A low MNA score can predict hospital-say outcomes in older patients and can be used to follow up changes in nutritional status. * Because of its validity in screening and assessing the risk of malnutrition, the MNA should be integrated in the comprehensive geriatric assessment. * In more than 10,000 elderly persons, the prevalence of undernutrition assessed by the MNA is 1% to 5% in community-dwelling elderly persons and outpatients, 20% in hospitalized older patients, and 37% in institutionalized elderly patients.