A complaint of unwillingness to eat in the elderly is often overlooked, both by the patient, the family, or the doctor. Such condition may have a more serious underlying background, such as infection. A reduced physiological deposit and different clinical manifestations gives importance lo the analysis of the problem of anorexia. Changes in body composition, reduced physical activity and basal metabolism rate, reduced Na+-Kl~-ATP-ase, teeth that are no longer in optimal condition, reduced taste and smell ability, increased CCK satiation effect, reduced gastric emptying, reduced NO-synthase activity of the gastric fundus, as well as reduced endogenous opioid level, could all influence the development of anorexia. In addition, there are also several other clinical conditions that play a role, such as polypharmacy, dementia, depression, and physiological disturbance in swallowing.