Relationship between dietary diversity and sleep quality: a Chinese community-based study

Objectives: The objective of this study was to examine the association between dietary diversity and sleep quality among Chinese middle-aged and older adults.

Methods: The Lifestyle and Healthy Aging of Chinese Square Dancer Study is a prospective, community-based cohort study that enrolled participants aged 45 years and above from 2020 to 2021. Using the semiquantitative food frequency questionnaire to investigate the diets of study participants, and using the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Dietary diversity was assessed using two scoring methods covering ten food groups and 66 food items, respectively: the dietary diversity score (DDS) and the food variety score (FVS). The higher scores of DDS and FVS indicated greater dietary diversity and higher dietary quality. Logistic regression analysis explored the associations between these scores and sleep quality.

Results: A total of 2409 individuals with completed information on PSQI and FFQ were included in this study, of whom 767 (31.8%) had poor sleep quality. Participants with higher DDS were associated with an 18% lower odds of poor sleep quality compared to those with low DDS (OR = 0.82, 95% CI, 0.68-0.98). Participants in the highest quartile of the FVS had a 32% lower odds of poor sleep quality than those in the lowest quartile (OR = 0.68, 95% CI, 0.52-0.89).

Conclusions: There was a positive correlation between higher FVS and DDS with better sleep quality. Therefore, ensuring a diverse diet may be beneficial for maintaining good sleep quality among middle-aged and older adults.