A composition contains one or more aromatic amino acids and optionally vitamin B6. The composition may be an oral nutritional composition, for example a nutritional supplement, an oral nutritional supplement, a food product, a food for special medical purpose (FSMP). The composition can be in a form of a powder, a powdered stick, a capsule or a solution. The composition can be administered to an individual in need thereof orally or intravenously for preventing and/or treating sarcopenia, a loss of and/or improving skeletal muscle mass, lean muscle mass, skeletal muscle strength and/or skeletal muscle function.