Dietary Branched-Chain Amino Acid Intake Is Associated with Muscle Mass and Handgrip Strength: Evidence from China-Health and Nutrition Survey 2015-2024.

Abstract

Objectives: This study aims to investigate the associations between dietary branched-chain amino acids (BCAAs) intake and appendicular skeletal muscle mass (ASM) as well as handgrip strength in Chinese adults.Methods: A total of 36,086 observations (54.32 ± 14.63 y) were included from the China Health and Nutrition Survey (CHNS) across three waves (2015, 2018, and 2022-2024). ASM was measured by bioelectrical impedance analysis, and handgrip strength was measured using a digital dynamometer. Dietary BCAA intake was assessed using three consecutive 24 h dietary recalls and adjusted for energy intake. Multilinear mixed-effect models were employed to examine the longitudinal association between BCAA intake and ASM. Multivariable regression was used to assess the cross-sectional association between BCAA intake and handgrip strength.Results: Dietary BCAA intake was significantly associated with ASM (β = 0.074, p < 0.05) with adjustment for potential confounding factors. This estimated positive effect increased with age in both males and females, and was consistently stronger in males. Compared with the lowest quintile (Q1), Q4 of dietary BCAA intake had higher handgrip strength (β = 0.721, p < 0.001). Stratified analyses showed that this association was more pronounced in males (Q4 vs. Q1: β = 1.016, p = 0.005) and in participants aged ≥65 years (Q4 vs. Q1: β = 1.024, p = 0.008).Conclusions: Dietary BCAA intake is recommended to maintain muscle mass and strength in Chinese adults.