Sarcopenia is an age-related progressive disease that increases the risk of falls, disability and death in the elderly, and brings a heavy economic burden to families and society. At present, nutritional supplementation is the main prevention and treatment of sarcopenia. Studies have confirmed that leucine and its metabolite β-hydroxy-β-methylbutyrate（HMB） can promote muscle protein production and inhibit muscle protein degradation, which is a key nutrient in sarcopenia formula foods. However, the optimal dose-response relationship is still unclear. This paper focuses on the key role of leucine and β-hydroxy-β-methylbutyrate in sarcopenia and its application in sarcopenia formula foods.