The Impact of Healthy Lifestyle Behaviors on Academic Achievement in Junior High School Students: A Longitudinal Mediation Analysis of Depressive Symptoms

Background. Lifestyle behaviors including sedentary behavior, diet, sleep and physical activity, and depressive symptoms have been shown to highly correlate with academic achievement. However, limited longitudinal studies have investigated the simultaneous relationship between these factors and academic achievement. Methods. A total of 325 junior high school students (53.8% female; M _age =13.56 years, SD = 0.62) from Guangdong Province participated in this study. Their mid-term and final scores for Chinese, Mathematics, and English were collected. Mediation analysis was used to evaluate the mediating role of depressive symptoms between lifestyle behaviors and academic achievement, while a hierarchical regression model was employed to examine the longitudinal relationship between lifestyle behaviors, depressive symptoms, and academic achievement. Results. The results indicated that students with healthier lifestyles performed better academically, with depressive symptoms serving as an important mediator. Furthermore, depressive symptoms were a significant longitudinal predictor of students' Chinese, Mathematics, and English grades, while lifestyle behaviors were only able to predict Chinese grades. Notably, sedentary behavior predicted academic achievement in all three subjects, namely Chinese, Mathematics, and English, longitudinally. In contrast, diet, sleep, and physical activity did not predict academic achievement. Conclusions. These findings suggest that maintaining physical and mental health, particularly by reducing sedentary behavior and depressive symptoms, could be a key behavioral goal for adolescents to enhance their academic achievement.