Anorexia of aging, defined as a loss of appetite and/or reduced food intake, affects a significant number of elderly people and is far more prevalent among frail individuals. Anorexia recognizes a multifactorial origin characterized by various combinations of medical, environmental and social factors. Given the interconnection between weight loss, sarcopenia and frailty, anorexia is a powerful, independent predictor of poor quality of life, morbidity and mortality in older persons. One of the most important goals in the management of older, frail people is to optimize their nutritional status. To achieve this objective it is important to identify subjects at risk of anorexia and to provide multi-stimulus interventions that ensure an adequate amount of food to limit and/or reverse weight loss and functional decline. Here, we provide a brief overview on the relevance of anorexia in the context of sarcopenia and frailty. Major pathways supposedly involved in the pathogenesis of anorexia are also illustrated. Finally, the importance of treating anorexia to achieve health benefits in frail elders is highlighted.