关键词: 屏幕暴露, 超重肥胖, 儿童, 青少年

Abstract: Objective To analyze the mediating pathway of the effect of screen exposure on overweight and obesity among children and adolescents,in order to provide evidence for the prevention and behavioral intervention of overweight and obesity in this population. Methods A total of 842 students in the same class from primary,junior and senior high schools in Zhejiang Province were selected by cluster random sampling method from September to November 2020.Data on demographic characteristics,body mass index (BMI),physical activity,frequency of eating while watching screens,and screen exposure were collected via questionnaires.Analysis of variance and chi-square test were used to compare the differences among non-and overweight and obesity groups,and the possible mediating effects were clarified. Results Among the 842 participants,205 (24.4%) were detected with overweight or obesity.Time of weekly more than one-hour physical activity was (3.0±2.3) days,and the average weekly screen exposure duration was (22.0±9.0) hours.Approximately 69.7% of children and adolescents had the habit of eating while watching screens.Screen exposure had no direct effect on BMI (β=-0.002,P=0.179), but could increase the risk of overweight and obesity through the mediating effect of physical activity (β =-0.030,P=0.001;β =-0.016,P=0.003). Conclusion Screen exposure increases the risk of overweight among children and adolescents by reducing their level of physical activity.

Key words: screen exposure, overweight and obesity, children, adolescents