Tamaki Hirose, Yohei Sawaya, Masahiro Ishizaka, Naori Hashimoto, Akira Kubo, Tomohiko Urano
BACKGROUND/OBJECTIVES: Although the associations between frailty and nutrition have been reported, no studies have focused on frailty recovery in relation to dietary diversity. This study aimed to clarify the association between frailty recovery and dietary variety, assessed using the Dietary Variety Score (DVS), over a 1-year period. METHODS: A prospective cohort study conducted in City A, Tochigi prefecture, Japan, included 353 individuals aged 73 and 78 years in 2023 who responded to surveys in both 2023 and 2024. The Kihon Checklist (KCL) and DVS were used for assessments. According to the KCL results, participants who were robust in both years or who improved from frailty or pre-frailty in 2023 to robust in 2024 were classified as the "robust-maintained/-recovered group," and all other participants were classified as "others." Statistical analyses included group comparisons and binomial logistic regression analysis to examine factors associated with the robust-maintained/-recovered group using DVS categories (high/low) or ten individual food groups as independent variables. RESULTS: The robust-maintained/-recovered group had a higher frequency of egg, soybean, soybean product, seaweed, potato, and fruit consumption. Furthermore, High DVS at baseline was significantly associated with the robust-maintained/-recovered group (odds ratio = 2.32, p < 0.001). A similar association was observed for soybean products (odds ratio = 1.83, p = 0.008). CONCLUSIONS: These findings suggest that sustained dietary diversity may be an effective strategy for recovery from frailty in older adults. Specifically, intake of traditional Japanese foods such as soybean products and "small food add-ons" such as seaweeds and fruits may offer a valuable approach to its management.