Abstract: Objective To evaluate the effect of childhood obesity intervention on body shape perception among primary school students,and to further explore the mediating role of body shape perception in changes in obesity indicators,in order to provide scientific evidence for future effective intervention strategies. Methods A randomized controlled trial for childhood obesity prevention was carried out in 8 primary schools in Changzhi from 2018 to 2019,and 393 children in grade four were included.A questionnaire was used to collect children's body shape perception,along with anthropometric measurements.Generalized estimating equation models were used to analyze the effect of intervention on children's body shape perception,and the mediation model was used to explore the role of body perception in changes in obesity indicators. Results After one year intervention,the proportion of the children's body shape perception conducive to weight loss (overestimated or correctly estimated) increased from 58.1% to 74.2% in the intervention group,while the proportion in the control group only increased from 53.8% to 58.4%.Compared to the controls,the intervention group showed a greater improvement on the proportion of body size perception conducive to weight loss(OR=1.638,95%CI:1.007 - 2.663,P<0.05).Stratified analysis revealed that the intervention had a larger effect on body shape perception for those who were overweight/obese(OR=2.247,95%CI:1.169~4.320) and for girls(OR=2.195,95%CI:1.080~4.458).Mediation analysis showed that changes in body shape perception played a mediating role in the relationship between comprehensive intervention and changes in body mass index(Z_a*Z_b=-0.13,95%CI:-0.30 - -0.01)and waist circumference(Z_a*Z_b=-0.85,95%CI:-1.87 - -0.08),but not in body fat percentage. Conclusions Comprehensive intervention can effectively improve children's body shape perception,and changes in body shape perception act as a mediator in improvements to obesity indicators.Incorporating body shape perception into comprehensive interventions can enhance the effectiveness of childhood obesity interventions.

Key words: obesity, body perception, mediating effect, comprehersive intervention, children

摘要： 目的 评估儿童肥胖综合干预对体形认知的影响,并探讨体形认知对肥胖指标变化的中介作用,为采取更为全面、有效的儿童干预策略提供科学依据。方法 基于2018年9月-2019年6月在长治市8所小学393名四年级学生中开展的儿童肥胖干预的随机对照试验,通过问卷调查收集儿童体形认知情况并对其进行体格测量,采用广义估计方程模型分析干预对儿童体形认知的影响及体形认知对肥胖指标变化的中介作用。结果 干预一学年后,干预组体形认知有利于减重(高估与正确估计)的比例从58.1%提高至72.2%,对照组有利于减重的比例从53.8%仅提高至58.4%。与对照组相比,干预组提高幅度更大(OR=1.638,95%CI:1.007~2.663,P<0.05)。分层分析显示:干预对超重肥胖者(OR=2.247,95%CI:1.169~4.320)、女生(OR=2.195,95%CI:1.080~4.458)体形认知影响较大;中介作用分析显示,体形认知变化在综合干预与儿童体质量指数(Z_a*Z_b=-0.13,95%CI:-0.30~-0.01)、腰围(Z_a*Z_b=-0.85,95%CI:-1.87~-0.08)变化的关联中存在中介作用,而与体脂百分比无关。结论 综合干预可有效改善儿童体形认知,体形认知变化是改善肥胖指标变化的中介因素。将体形认知纳入综合干预可提高儿童肥胖干预效果。

关键词: 肥胖, 体形认知, 中介效应, 综合干预, 儿童