護理師正在為年長者提供健康飲食教育。哪種營養素對預防肌肉流失（肌少症）特別重要？

肌少症（Sarcopenia）是指隨著年齡增長，肌肉質量和功能逐漸流失的現象。預防肌少症的核心在於確保足夠的「蛋白質（Protein）」攝取，因為蛋白質中的胺基酸是肌肉組織修復與合成的基礎原料。老年人的蛋白質合成效率降低，若攝取量不足，身體會分解肌肉來維持其他生理機能，導致肌肉流失。除了飲食攝取，適度的阻力運動（Resistance exercise）同樣重要，護理師應衛教老年人採取高蛋白飲食並配合運動。

Sarcopenia refers to the progressive loss of muscle mass and function that occurs with aging. The cornerstone of sarcopenia prevention is ensuring adequate protein intake, because the amino acids in protein are the basic raw materials for muscle tissue repair and synthesis. Older adults have decreased efficiency of protein synthesis; if intake is insufficient, the body will catabolize muscle to maintain other physiological functions, leading to muscle loss. In addition to dietary intake, moderate resistance exercise is equally important, and the nurse should counsel older adults to adopt a high-protein diet combined with exercise.