Effects of oral supplementation of β -hydroxy-β -methylbutyrate on muscle mass and strength in individuals over the age of 50: a meta-analysis - Li, Nan; Chen, Shanbin; He, Yuxi; Chen, Yamin; Duan, Xiaosa; He, Wenxing; Wang, Qihe; Liu, Sana; Liu, Tongbo; Fang, Haiqin (Frontiers in Nutrition, 2025)