Sarcopenia and nutrition.

Preserving or restoring adequate nutritional status is a key factor to delay the onset of chronic diseases and to accelerate recovery from acute illnesses. In particular, consistent and robust data show the loss of muscle mass, that is, sarcopenia, is clinically relevant since it is closely related to increased morbidity and mortality in healthy individuals and patients. Sarcopenia is defined as the age-related loss of muscle mass and function. International study groups have recently proposed separate definitions and diagnostic criteria for sarcopenia. Unfortunately, the rate of agreement in assessing the prevalence of sarcopenia is just fair, which highlights the need for a common effort to harmonize definitions and diagnostic criteria. Sarcopenia should be distinct from myopenia, which is the disease-associated loss of muscle mass, although in clinical practice it may be impossible to separate them (i.e., in old cancer patients). The pathogenesis of sarcopenia is complex and multifactorial. Consequently, its treatment should target the different factors involved, including quantitatively and qualitatively inappropriate food intake and reduced physical activity.