No dramatic shifts in BMI for overweight girls a year after receiving fitness assessment

Teens being classified as overweight in school fitness reports does not appear to have any impact on short-term changes in body mass index, finds a new study by New York University's Institute for Education and Social Policy, the Center for Policy Research at Syracuse University's Maxwell School of Citizenship and Public Affairs, and Columbia University.

The study appears in the journal Proceedings of the National Academy of Sciences.

Because dietary and exercise habits are established in childhood, public health officials have advocated for early obesity and severe obesity surveillance and prevention. Providing families with fitness assessments may be beneficial because, surprisingly, many parents are unaware of their children being overweight or obese. This lack of awareness becomes a barrier for children achieving healthier weights. Opponents of these assessments argue that informing children that they are overweight can be stigmatizing, hurts their self-esteem, or could encourage bullying.

U.S. schools are increasingly reporting the weight, height, and fitness of students, and sharing the results with students and their parents. New York City's public schools adopted a fitness assessment in 2007-2008 that includes measures for health-related fitness, as well as students' body mass index (BMI), a calculation of height and weight. While the current reports show student BMI as falling within a "healthy fitness zone" or in a "needs improvement" category, at the time of the study labels included underweight, healthy weight, overweight, and obese. For students in a "needs improvement category," the report includes recommendations to speak with a health care provider.

"Over one third of New York City public school students are either overweight or obese. This is troubling because childhood obesity predicts obesity in adulthood and is strongly associated with success in school," said Amy Ellen Schwartz, director of the NYU Institute for Education and Social Policy and the Daniel Patrick Moynihan Chair in Public Affairs at Syracuse University's Maxwell School of Citizenship and Public Affairs.

Using administrative data from the New York City Department of Education, the researchers analyzed 3,692,026 BMI records for public school students from 2007-2012. They focused on the 442,408 female students whose BMI fell close to the overweight designation that was used during that time period, comparing those just above to those just below this threshold. This study was confined to high school data, and the study did not assess whether the reports resulted in parents or teens talking to their health care provider about the results.

The researchers sought to understand what effect being designated as overweight or healthy in one year's report card would have on the following year's BMI. Their analyses show that the overweight label was associated with a small increase in female students' BMI, particularly among high school seniors and those newly identified as overweight in last year's report card.

The researchers caution that the findings from this study only apply to female public school students near the overweight cutoff, and do not apply to the overall effect of BMI reporting in New York City's schools. In addition, the data used for this study does not reveal whether the reports were actually received by parents, or whether or to what extent they were read and processed by the students or the parents. The analysis was performed on data ending in 2011-12 and there have been substantial changes to reporting of fitness and BMI since then.

Given the potential value in school fitness reports, the researchers are continuing to work closely with school agencies to make them as useful to parents as possible. They are continuing their research using a randomized control trial study design with a subset of schools to study the effectiveness of various delivery and/or reminder methods.