Weight loss in older persons is associated with a variety of deleterious effects, including hip fracture, pressure ulcers, decreasing immune function, decreased functional status, and death. There are 4 major causes of weight loss: anorexia, sarcopenia, cachexia, and dehydration. Many of the reasons for the development of these conditions are treatable. For example, depression is the most common cause of weight loss in the elderly. Early screening for anorexia can be undertaken in the physician's office utilizing the Simplified Nutritional Assessment Questionnaire. An algorithmic approach to the office management of weight loss is provided.