Suboptimal dietary quality is associated with mental symptoms among adults aged 40 years and over in China: A population-based cross-sectional study

Background: The previous studies an association between dietary patterns and psychiatric symptoms. However, few studies have examined the association of quality of dietary patterns and anxiety, depressive symptoms in the Chinese population. Methods: Between 2017 and 2019, a population-based, cross-sectional survey was carried out in China. Uniformed questionnaires collected the demographic characteristics and food data. The dietary quality of the adults was evaluated using the revised Diet Balance Index 2016 (DBI-16). We measured anxiety and depression symptoms using the the Generalized Anxiety Disorder (GAD)-7 and Patient Health Questionnaire (PHQ)-9. Results: A total of 73,737 participants were recruited during the survey period. 17.6 % and 13.7 % of residents suffer from anxiety and depression symptoms, respectively. The DBI-16 indicates that participants with anxiety or depression symptoms had higher scores of low bound score (LBS, refers to inadequate food intake) and dietary quality distance (DQD, refers to unbalanced food intake) than those without anxiety or depression. The logistic regression models showed that high levels of LBS and DQD problems were more strongly associated with anxiety (LBS:OR = 1.20, DQD:OR = 1.30) and depressive symptoms (LBS:OR = 1.21, DQD:OR = 1.44). On the contrary, higher bound score (HBS, refers to excessive food intake) was significantly negatively correlated with symptoms of anxiety and depression. Moreover, each increase in the food group was associated with 4 % lower odds of anxiety and 6 % lower odds of depression symptoms. Limitations: Cross-sectional design and self-reporting of psychological symptoms and dietary information limit the generalizability of the results. Conclusion: The dietary quality of adults aged 40 years and over in China is suboptimal, with excessive and inadequate food intake simultaneously. Dietary imbalance, and low dietary diversity may be related to anxiety and depressive symptoms.