Associations between Dietary Behaviors and Physical Activity and Mental Health Disorders among Chinese Residents Aged 18-60: A Cross-Sectional Study

Objective Our aim was to study the associations of dietary behavior and physical activity intensity with anxiety and depressive symptoms in Chinese adults, as well as their dose‒response relationships. Method The data originated from the Psychology and Behavior Investigation of Chinese Residents (PBICR) project. We categorized poor dietary behavior and physical activity intensity based on the Dietary Guidelines for Chinese Residents (2022) and the IPAQ-7 questionnaire. Poor dietary behavior encompassed five aspects: sugary drink consumption, alcohol intake, skipping breakfast, eating out, and dieting. Physical activity was classified into three levels: low, medium, and high. Ordered logistic regression was used to estimate the adjusted odds ratios and 95% confidence intervals for depressive and anxiety symptoms. A restricted cubic spline analysis further explored the dose‒response relationship between anxiety/depression rates and unhealthy dietary behaviors. Results A total of 43.61%, 45.42%, and 52.29% of people with low, moderate and high physical activity levels, respectively, suffer from anxiety. A total of 55.76%, 51.73%, 58.25%, 53.68%, and 64.51% of people with bad eating habits, such as sugary drinks, drinking, skipping breakfast, eating out, suffer from anxiety. Individuals who engage in low, moderate and high levels of physical activity experience depression at a rate of 54.29%, 57.36%, and 63.90%, respectively. Individuals who consumed sugary drinks or alcohol, frequently skipped breakfast, dined out frequently, or were on a diet exhibited depression rates of 68.40%, 62.91%, 65.22%, and 76.22%, respectively. After adjusting for the same variables, the types of unhealthy eating behaviors and levels of physical activity were positively correlated with anxiety: sugary drinks (aOR = 1.38; 95% CI = 1.27, 1.41), alcohol consumption (aOR = 1.31; 95% CI = 1.21, 1.41), skipping breakfast (aOR = 1.65; 95% CI = 1.51, 1.80), eating out of home (aOR = 1.19; 95% CI = 1.09, 1.30), diet (aOR = 1.95; 95% CI = 1.75, 2.16), and physical activity level (mid: aOR = 1.02; 95% CI = 0.95, 1.11; high: aOR = 1.95; 95% CI = 1.36, 1.47), as well as the same changes in depressive moods. Conclusion The increasing risk of anxiety and depression is associated with a growing number of unhealthy dietary habits, resulting in a commensurate increase in these mental health concerns.