Tracking Students' BMI May Have No Effect on Student Health, Suggests Study
Guest post by Evie Blad. Cross-posted from the Rules for Engagement blog.
Notifying parents of a student's body mass index may not be an effective way to address childhood obesity, a new study found.
Such reporting has grown increasingly popular over the last decade, despite limited research about the strategy's effectiveness and concerns that tracking students' size could lead to problems with body image and self esteem.
Arkansas' Act 1220, signed into law in 2003, was a pioneering comprehensive childhood obesity law that included the BMI reporting requirement. "Since then, eight other states have adopted similar school-based, BMI screening and notification policies," says a study by University of California at Davis researcher Kevin Gee published in the Journal of Adolescent Health.
After studying data from Arkansas, Gee found that students who received the BMI ratings in 11th and 12th grade did not have different health outcomes from students who did not. He found no statistically significant differences between the changes in self-reported diet and exercise behaviors or body mass index of the two groups.
To draw his conclusions, Gee compared data gathered from the Centers for Disease Control's Youth Risk Behavior Survey from the students' 10th and 12th grade years. All of those children had been previously screened in younger grades.
"In 2007, due to mounting concerns about a lack of a parental opt-out of screening requirements as well as the administrative burden of screening, the Arkansas General Assembly implemented Act 201, which allowed parental opt-out from screenings and exempted children in odd-numbered grades as well as in grade 12," the study says. "This exemption raised a unique opportunity to compare the health outcomes of adolescents who were subject to screening and reporting in 11th and 12th grades to those who were exempt from screening and reporting in order to understand the effect of screening and reporting requirements in late adolescence."
Of course, this is secondary data that was collected after the fact. In an ideal study, Gee would pre-select a large representative group of students to receive BMI screenings and parental notifications and track their progress over time compared to an equally large and representative control group.
But it does raise some questions about whether schools are seeing any positive returns in exchange for the time and resources they use to collect and report this information.
What sort of health data should schools collect?
While some have questioned the value of reporting student BMIs, policy makers and child-health advocates do see value in measuring and tracking some forms of school health data.
As I wrote last year, a growing number of states and school systems are integrating health metrics into their school improvement goals and, consequently, into the information they share with the public to boost accountability. That data is typically system-level information, such as the average amount of time students have for recess at a school and whether or not they have access to a school-based health center.
In addition, some states are tracking individual student health indicators, like BMI, to explore their link with academic achievement and to test the effectiveness of interventions like new school wellness programs.
Read more about those efforts in my story about school health metrics.