[The association between lifestyle behavior and risk of overweight and depression comorbidity in children aged 7 to 9 years in Tianjin City].

<b>Objective:</b> To explore the association between lifestyle behavior and the risk of overweight and depression comorbidity in children aged 7 to 9 years in Tianjin City. <b>Methods:</b> The random cluster sampling was used to conduct a baseline survey among 1 632 7-year-old children in Tianjin in 2021, and the follow-up survey was then conducted in 2023. Age, gender and lifestyle behavior of children were collected at baseline and follow-up, and physical examination and depression symptom evaluation were also performed. Four behavioral factors, including sugary beverage intake, physical activity, screen time duration, and sleep duration, were included in the comprehensive lifestyle score, with a total score of 0 to 4 points. A higher score means a better lifestyle. The multi-nominal logistic regression model was used to analyze the association between lifestyle behavior changes at different time points and the risk of overweight and depression comorbidity. <b>Results:</b> The mean age of the children was (7.72±0.62) years at baseline and (9.61±0.62) years at follow-up, with 350 boys (52.08%). After adjusting for confounding factors, the results showed that compared to children with moderate lifestyle behavior, those with poor lifestyle behavior had a higher risk of overweight and depression comorbidity both at baseline and follow-up (Baseline: <i>OR</i>=2.62, 95%<i>CI</i>: 1.28-5.37; Follow-up: <i>OR</i>=2.28, 95%<i>CI</i>: 1.26-4.11), while those with a better lifestyle behavior had a lower risk of depression during follow-up (<i>OR</i>=0.35, 95%<i>CI</i>: 0.19-0.64). Based on the comprehensive baseline and follow-up lifestyle behaviors, it was found that children with improved lifestyle were more likely to experience the disappearance of overweight and depression comorbidity (<i>OR</i>=1.29, 95%<i>CI</i>: 1.04-1.61), and were less likely to develop overweight and depression comorbidity (<i>OR</i>=0.82, 95%<i>CI</i>: 0.69-0.97). <b>Conclusion:</b> There is an association between lifestyle behavior and overweight and depression comorbidity among children aged 7 to 9 years in Tianjin. Improvement in children's lifestyle behavior may reduce the risk of overweight and depression comorbidity.