Risk for or established malnutrition is frequent in older adults, accompanied by functional limitations, increased morbidity and mortality. Protein-energy malnutrition is often observed and leads besides other predisposing factors to sarcopenia, the increased loss of muscle mass with aging. Sarcopenia is an integral correlate of the physical component of the frailty syndrome. Even though sarcopenia often reaches levels where mobility, balance and functionality on overall are hampered, its diagnosis has not become part of the standard diagnostic and therapeutic repertoire of geriatric medicine. This will hopefully change with a recently published revised international definition of sarcopenia, as well an own ICD-number. From a pathophysiological point of view, both malnutrition and sarcopenia share many components, a low-inflammatory state (inflamm-aging) being an important one. Nutritional interventions with and without parallel physical activity programs can prevent and often also reverse sarcopenia. It is hoped that upcoming even more potent nutritional treatment options—including for sarcopenic obesity—will lower the burden of malnutrition and sarcopenia for many older adults.