Protein Supplementation Intervention for Improving Muscle Mass and Physical Performance in Older People With Sarcopenia: A Randomized, Double-blind, Placebo-controlled Trial

Background: Declines in muscle mass and strength are expected with aging, but physical inactivity and low protein intake have been suggested as risk factors of sarcopenia. So far, lifestyle interventions, especially exercise and nutritional supplementation, prevail as mainstays of treatment for sarcopenia. Objective: To explore the effect and benefits of protein supplementation on the improvement of muscle mass and physical performance in older people with sarcopenia. Design: A randomized, double-blind, placebo-controlled clinical trial. Methods: Participants aged 65-95y who meet the following criteria will be invited: (1) muscle mass: bioimpedance, \<7.0 kg/m² (male) and \<5.7 kg/m² (female), (2) handgrip strength: \<28 kg (male) and \<18 kg (female), and (3) low physical performance: 6-m gait Speed \<1.0 m/s. Study participants will be randomly assigned to two groups. The experimental group will receive a 12-week intervention with【protein (14g)+ BCAA(4.4g)】 drink per day, while the parallel control group will receive a placebo oat drink per day. Participants in the control group will be asked to maintain participants' usual diet and physical activity. There are 3 time-points to measure outcomes and observe other required information, at week 0(baseline), 6 and 12.