Berkeley Food Institute, University of California, Berkeley, Berkeley.
Community Health Sciences, School of Public Health, University of California, Berkeley, Berkeley.
JAMA Pediatr. 2021 Mar 1;175(3):251-259. doi: 10.1001/jamapediatrics.2020.4768.
Annually, US schools screen millions of students' body mass index (BMI) and report the results to parents, with little experimental evidence on potential benefits and harms.
To determine the impact of school-based BMI reporting on weight status and adverse outcomes (weight stigmatization and weight-related perceptions and behaviors) among a diverse student population.
DESIGN, SETTING, AND PARTICIPANTS: Cluster randomized clinical trial. The Fit Study (2014-2017) randomized 79 California schools to BMI screening and reporting (group 1), BMI screening only (group 2), or control (no BMI screening or reporting [group 3]) in grades 3 to 8. The setting was California elementary and middle schools. Students in grades 3 to 7 at baseline participated for up to 3 years. A modified intent-to-treat protocol was used. Data analysis was conducted from April 13, 2017, to March 26, 2020.
School staff assessed BMI each spring among students in groups 1 and 2. Parents of students in group 1 were sent a BMI report each fall for up to 2 years.
Changes in BMI z score and in adverse outcomes (based on surveys conducted each fall among students in grades 4 to 8) from baseline to 1 and 2 years of follow-up.
A total of 28 641 students (14 645 [51.1%] male) in grades 3 to 7 at baseline participated in the study for up to 3 years. Among 6534 of 16 622 students with a baseline BMI in the 85th percentile or higher (39.3%), BMI reporting had no effect on BMI z score change (-0.003; 95% CI, -0.02 to 0.01 at 1 year and 0.01; 95% CI, -0.02 to 0.03 at 2 years). Weight dissatisfaction increased more among students having BMI screened at school (8694 students in groups 1 and 2) than among control participants (5674 students in group 3). Results of the effect of BMI reporting on other adverse outcomes were mixed: compared with the control (group 3), among students weighed at school (groups 1 and 2), weight satisfaction declined more after 2 years (-0.11; 95% CI, -0.18 to -0.05), and peer weight talk increased more after 1 year (0.05; 95% CI, 0.01-0.09); however, concerning weight control behaviors declined more after 1 year (-0.06; 95% CI, -0.10 to -0.02).
Body mass index reports alone do not improve children's weight status and may decrease weight satisfaction. To improve student health, schools should consider investing resources in evidence-based interventions.
ClinicalTrials.gov Identifier: NCT02088086.
美国学校每年对数百万学生的身体质量指数（BMI）进行筛查，并将结果告知家长，但几乎没有关于潜在益处和危害的实验证据。
确定基于学校的 BMI 报告对不同学生群体的体重状况和不良结果（体重污名化以及与体重相关的认知和行为）的影响。
设计、设置和参与者：这是一项整群随机临床试验。Fit 研究（2014-2017 年）将 79 所加利福尼亚学校随机分为 BMI 筛查和报告组（第 1 组）、BMI 筛查组（第 2 组）和对照组（不进行 BMI 筛查或报告[第 3 组]），这些学校分布在加利福尼亚州的小学和中学。基线时有 3 至 7 年级的学生参与，时间最长为 3 年。采用改良意向治疗方案。数据分析于 2017 年 4 月 13 日至 2020 年 3 月 26 日进行。
第 1 组和第 2 组的学校工作人员每年春季对学生的 BMI 进行评估。第 1 组学生的家长在秋季收到一份 BMI 报告，时间最长为 2 年。
从基线到 1 年和 2 年随访时，BMI z 分数和不良结果（基于 4 至 8 年级学生每年秋季进行的调查）的变化。
共有 28641 名 3 至 7 年级的学生（男性 14645 名[51.1%]）参与了这项研究，时间最长为 3 年。在基线 BMI 位于第 85 百分位或更高的 16622 名学生中的 6534 名（39.3%）中，BMI 报告对 BMI z 分数的变化没有影响（第 1 年为-0.003；95%CI，-0.02 至 0.01，第 2 年为 0.01；95%CI，-0.02 至 0.03）。与对照组（第 3 组）相比，在学校接受 BMI 筛查的学生（第 1 组和第 2 组中的 8694 名学生）中，体重不满的情况增加更多。BMI 报告对其他不良结果的影响结果不一：与对照组（第 3 组）相比，在学校接受体重测量的学生（第 1 组和第 2 组）中，体重满意度在 2 年后下降更多（-0.11；95%CI，-0.18 至 -0.05），在 1 年后，同伴间关于体重的讨论增加更多（0.05；95%CI，0.01-0.09）；然而，在 1 年后，关注体重控制行为的学生减少更多（-0.06；95%CI，-0.10 至 -0.02）。
单独的 BMI 报告并不能改善儿童的体重状况，反而可能降低体重满意度。为了改善学生的健康状况，学校应该考虑投资于基于证据的干预措施。
ClinicalTrials.gov 标识符：NCT02088086。
