Adolescents' static behaviors and related factors in Shanghai

Objective To investigate and analyse the related factors of static behavior among adolescents, such as screen time, mild physical activity, moderate and vigorous physical activity, and nutritional status. Methods In 2011, multistage sampling was done from 10 classes of three middle schools in three districts in Shanghai;the students filled the questionnaire on their own which recorded all of the activities of one school day and one weekend day. The data was analyzed by general describing analysis, correlation analysis, and Kruskal-Wallis test. Results The static time in weekend was 389.19 minutes per day, the screen time was 122.93 minutes per day, and both were over three times those on one school day. The static time was not related to moderate and vigorous physical activity, but was related to mild physical activity. The difference in mean time before the screen at weekend was statistically significant between obesity group, overweight group, normal group, low weight group and malnutrition group. Conclusion Adolescents lacked adequate physical activities in their spare time, and behavior before the screen might be related to their poor nutrition status.