Associations of dietary patterns, dietary motivations, and nutritional status with skeletal muscle mass in underserved Chinese older adults: A structural equation modeling

This study aimed to explore the relationships between dietary patterns, motivation, nutritional status, and skeletal muscle mass, guided by the Self-Determination Theory. This study employed a cross-sectional survey. We invited 249 older adults using the convenience sampling method from suburban and rural areas of Hunan Province from April to December 2023. Data were collected using the Eating Motivation Survey (TEMS), the Mini Nutritional Assessment-Short Form (MNA-SF), and the Chinese version of the Food Frequency Questionnaire (FFQ). Bioelectrical Impedance Analysis was used to assess body composition, with skeletal muscle mass standardized using the Relative Skeletal Muscle Index (RSMI). Principal component analysis (PCA) was employed to extract dietary patterns, and structural equation modeling (SEM) was used to assess interaction paths. Two distinct dietary patterns emerged. Both dietary patterns (dietary pattern 1: β = 0.338, P < 0.001; dietary pattern 2: β = 0.430, P < 0.001) and nutritional status ( β = 0.177, P = 0.008) positively influenced skeletal muscle mass. An indirect relationship was found between dietary patterns and nutritional status (dietary pattern 1: β = 0.064, P < 0.001; dietary pattern 2: β = 0.649, P < 0.001). Dietary motivation was influenced by gender and educational background and had positive effects on nutritional status ( β = 0.278, P < 0.001), dietary patterns (pattern 1: β = 0.124, P = 0.050; pattern 2: β = 0.272, P < 0.001), and skeletal muscle mass ( β = 0.162, P < 0.001). Dietary patterns directly affect nutritional status and skeletal muscle mass, with this effect mediated by dietary motivation. These findings underscore the necessity for tailored, motivation-based interventions in older adults to enhance dietary adherence and muscle health outcomes.