Association of Dietary Variety with Body Composition and Physical Function in Community-dwelling Elderly Japanese

To examine the associations of dietary variety with body composition and physical function in community-dwelling elderly Japanese.

Cross-sectional study.

Community-based.

A total of 1184 community-dwelling elderly adults aged 65 and over.

Dietary variety was assessed with a food frequency questionnaire (maximum, 10 points) that encompassed the 10 main food components of Japanese meals (meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruit, seaweed, and fats/oils). Body composition was determined by multifrequency bioelectrical impedance analysis. Physical function was assessed by measuring grip strength and usual walking speed. Multiple linear regression analysis was used to examine the associations of dietary variety with body composition and physical function.

After adjusting for potential confounders, higher dietary variety scores were independently associated with higher lean mass (β (SE): 0.176 (0.049), p<0.001) and appendicular lean mass (β (SE): 0.114 (0.027), p<0.001) but not with body fat mass. Elders with a higher dietary variety score had greater grip strength and faster usual walking speed (β (SE): 0.204 (0.071), p=0.004, and β (SE): 0.008 (0.003), p=0.012, respectively).

Greater dietary variety was significantly associated with greater lean mass and better physical function in Japanese elders. The causal relationship warrants investigation in a prospective study.