Dietary diversity and healthy life expectancy among Chinese older adults: a multistate analysis of CLHLS, 2008-2018.

Abstract

Objective: This study estimated healthy life expectancy (HLE) among Chinese older adults across varying levels of dietary diversity, and examined sex and urban-rural differences.

Methods: Drawing on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018, data on 9,953 older adults aged 65 years and older were included. Transition probabilities among health statuses were estimated. Further, a microsimulation model was used to calculate life expectancy (LE), HLE, and HLE/LE for older adults with varying levels of dietary diversity. Sex and urban-rural differences were also examined descriptively. Z-tests were applied to determine whether differences in HLE within subgroups were statistically significant (p < 0.05).

Results: Compared with older adults with low dietary diversity, those with high dietary diversity exhibited a higher probability of transitioning from health to disability. However, they also exhibited a greater likelihood of recovering from disability and returning to health. Additionally, older adults with high dietary diversity exhibited lower transition probabilities to death from both health and disability. Across all age groups, older adults with high dietary diversity had higher LE and HLE values, albeit with lower HLE/LE ratios. At age 65, the difference in LE between the low- and high-dietary-diversity groups was 1.26 years [14.54 years (95% CI: 14.42-15.34) versus 15.80 years (95% CI: 15.55-16.17)]. Meanwhile, the corresponding difference in HLE was 0.90 years [13.32 years (95% CI: 13.25-13.95) versus 14.22 years (95% CI: 13.91-14.58)]. Stratified analyses further indicated that differences in HLE between dietary diversity groups were consistently observed across sex and urban-rural residence groups. Descriptively, the differences appeared larger among men and urban residents.

Conclusion: Higher dietary diversity was associated with a higher probability of transition from disability to health, lower probabilities of transition from either health or disability to death, and higher LE and HLE. These associations were observed across sex and urban-rural residence groups. Descriptively, larger differences in HLE between dietary diversity groups were observed among males and urban residents.