Effects of dietary diversity on frailty in Chinese older adults: a 3-year cohort study

BACKGROUND: Frailty has emerged as a global health burden with increased population aging. A diverse diet is essential for an adequate and balanced supply of nutrients. However, limited evidence supports the relationship between dietary diversity and frailty. We therefore assessed the associations of dietary diversity with the risk of frailty. METHODS: We used the Chinese Longitudinal Healthy Longevity Survey to analyze a prospective cohort of Chinese older adults. A total of 1948 non-frail older adults were included in the final sample. Participants were categorized into groups with high or low dietary diversity scores (DDSs) using a food frequency questionnaire. A Generalized Estimating Equation were used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for determining frailty incidence. RESULTS: Among 1,948 participants, 381 had frailty with the prevalence of 19.56% during the 3-year follow-up period. Compared with the low DDS group, the high DDS group exhibited a lower risk of frailty (RR, 0.72; 95% CI: 0.57–0.91). Compared with those with a consistently low DDS, the RR of participants with a consistently high DDS for frailty was 0.56 (95% CI: 0.42–0.74). Moreover, meat, beans, fish, nuts, fresh fruits, and fresh vegetables were inversely associated with frailty. In stratified analysis, a consistently high DDS, compared with a consistently low DDS, reduced the risk of frailty for people aged 65-79 years and those living in town and rural areas. CONCLUSION: This study found a prospective association between dietary diversity and frailty among Chinese older adults. These findings stressed that it is important to improve dietary diversity for older adults to promote healthy ageing, particularly for young older adults and in town and rural areas. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-023-03875-5.