体育活动和屏幕暴露对运动乐趣与小学生体质指数关系的多重中介作用

The multiple mediating effects of physical activity and screen exposure between sport enjoyment and BMI among primary school students

目的 分析运动乐趣与小学生体质量指数(body mass index, BMI)的关系,探讨体育活动和屏幕暴露在其中的多重中介作用,为小学生超重肥胖控制提供新的干预思路和策略措施。方法 采用整群抽样的方法,于2021年6月选取贵州省六盘水市某小学973名小学生作为研究对象。采用运动乐趣量表、体育活动等级量表和屏幕暴露问卷进行调查。使用Mplus 7.0软件进行中介模型检验,并用Bootstrap法进行多重中介效应分析。结果 调查对象运动乐趣得分平均为(17.34±3.31)分,体育活动量平均为(21.84±13.58)分。在学习日屏幕暴露≤2 h/d者占86.18%,在周末占57.41%。BMI为(17.07±1.05) kg/m2,超重肥胖率为23.08%。运动乐趣、体育活动与BMI分别成负相关(r=-0.482、-0.451,均P<0.01);学习日、周末屏幕暴露与BMI均成正相关(r=0.359、0.462,均P<0.01)。体育活动在运动乐趣与BMI之间起中介作用,中介效应占总效应26.75%;屏幕暴露也起中介作用,中介效应占总效应9.58%;体育活动和屏幕暴露起链式中介作用,中介效应占5.19%。结论 体育活动和屏幕暴露在运动乐趣与BMI间起多重中介作用。建议在进行小学生超重肥胖的干预时,应注重对小学生运动乐趣的培养,同时不能忽视体育活动促进以及对屏幕暴露的合理控制。

Objectives To analyze the relationship between sport enjoyment and body mass index(BMI) among primary school students, and to explore the multiple mediating effects of physical activity and screen exposure between sport enjoyment and BMI, so as to provide evidence for scientifically formulating intervention strategies for the control of overweight and obesity of primary school students. Methods A cluster sampling method was used to randomly select 973 students from a primary school in Liupanshui city, Guizhou province in June 2021. A survey was conducted using sport enjoyment scale, physical activity rating(PAR) scale-3 and screen exposure questionnaire to collect study related information. The mediation model was tested by Mplus 7. 0, and the multi-mediating effect was analyzed by Bootstrap method. Results The mean score of sport enjoyment was(17. 34±3. 31), and the mean PAR score was(21. 84±13. 58), 86. 18% and 57. 41% students spent ≤2 h/d on screen during weekdays and weekends, respectively. The mean BMI was(17. 07±1. 05) kg/m2, and the overweight and obesity rate was 23. 08%. Sport enjoyment and physical activity were negatively correlated with BMI(r=-0. 482,-0. 451, P<0. 01, respectively);screen exposure time during weekdays and weekends were positively correlated with BMI(r=0. 359, 0. 462, P<0. 01, respectively). Both physical activity and screen exposure mediated the relationship between sport enjoyment and BMI, the mediating effect accounted for 26. 75% and 9. 58% of the total effect, they also played a chain mediation effect, which accounted for 5. 19%.Conclusions There is a significant relation between sport enjoyment and BMI, and physical activity and screen exposure play multiple mediating roles between them. It’s suggested that during the intervention for overweight and obesity of primary school students, more attention should be paid to develop their sport enjoyment, meanwhile, the promotion of physical activity and the control of screen exposure should not be ignored.