Examining the efficacy of BMI “report cards”

Over the past decade as the obesity epidemic has intensified, there have been many suggestions to tackle obesity in childhood. One of the most common interventions was measuring a child’s body mass index (BMI) and reporting the results to the child. However, the effectiveness of these BMI “report cards” has been questioned since they first started being used. An investigation in JAMA Pediatrics offers some much-needed information of the efficacy.¹

The investigators ran a cluster randomized clinical trial and used the Fit Study, from 2014 to 2017. In the study, 79 schools in California were randomized into 3 arms, students in grades 3 to 8 were either given BMI screenings that were reported to parents; received only a BMI screening; or the control arm, which included no BMI screening or reporting. The study’s setting were elementary and middle schools in California. The students in grades 3 to 7 at the study’s baseline participated for up to 3 years. The BMI screenings occurred in the spring and reports were sent to parents.

During the course of study, 28,641 students participated in it. Among the 6534 of 16,622 children who had a baseline BMI in the 85th percentile or higher, the investigators found that the reporting of BMI 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). Additionally, they found that weight dissatisfaction went up more among student who received a BMI screening at school (8694 students) than among control participants who did not get a screening at school (5674 students). Weight satisfaction went down after 2 years more among students who were given a BMI screening or report (−0.11; 95% CI, −0.18 to −0.05). The children who received a BMI screening and report led to increased peer weight talk (0.05; 95% CI, 0.01-0.09). However, the investigators also found that concerning behaviors meant to control weight went down after 1 year in children who were screened (−0.06; 95% CI, −0.10 to −0.02).

The researchers concluded that body mass index reports on their own led to no improvement in a child’s weight status. In fact, the reports could decrease weight satisfaction, which could combine with other elements to make a child feel stigmatized because of weight, which has been shown to be counterintuitive. They urge schools to invest in evidence-based interventions to improve the student body’s health.

Reference

1. Madsen K, Thompson H, Linchey J, et al. Effect of school-based body mass index reporting in California public schools. JAMA Pediatr. November 16, 2020. Epub ahead of print. doi:10.1001/jamapediatrics.2020.4768