Risk factors for dietary variety decline among Japanese elderly in a rural community: a 8-year follow-up study from TMIG-LISA

Objective: To examine the factors related to the decline of dietary variety among the rural community-dwelling Japanese elderly people and the implication on the planning of elderly people's nutritional improvement program in the future. Design: A prospective cohort study during 8-year follow-up from 1992 to 2000. Setting: This study was conducted in Nangai Village, a rural and mainly agricultural area of Akita Prefecture in the northern part of Honshu, one of four main islands in Japan. Subjects: A total of 417 elderly people ( 160 men, 257 women) who completed interviews and food intake frequency surveys conducted in 1992, 1994, 1996, 1998, and 2000 were studied. Methods: Dietary variety and variables potentially associated with dietary variety decline were identified from a face-to-face interview at the baseline and 8-year follow-up surveys. The dietary variety was measured using the dietary variety score (DVS), which covers the 10 main food groups in Japanese meals. Results: During the 8-year follow-up, 36.2% of the subjects showed a decline in dietary variety. Health characteristics also change among the 8-year follow-up and these changes have an effect on the decline of dietary variety. Significant predictors for decline in dietary variety included loss of spouse, deterioration in self-perceived chewing ability, and decrease in intellectual activity score. Conclusions: Loss of spouse, deterioration in chewing ability, and decline in intellectual activity may increase the risk of decline in dietary variety in community-dwelling Japanese elderly people.