Schools have manned the front lines of the battle against childhood obesity. First Lady Michelle Obama has promoted low-cal lunches, fresh produce and more through the “Healthy, Hunger-Free Kids Act of 2010.” Now, she hopes to ban junk food and soda marketing in schools. Are these efforts enough to turn the tide?
These healthy initiatives may not be enough to negate the impact of other unhealthy influences in students’ homes and neighborhoods, according to Tracy Richmond, MD, MPH, of Boston Children’s Hospital’s Division of Adolescent Medicine.
“Of course, offering healthy food and promoting physical activity are good things. The question is whether these efforts are having the desired impact,” says Richmond, who published a study in January 2014 in PLOS One that sought to determine how a school’s physical activity or nutrition resources might be linked with fifth grade students’ body mass index (BMI).
The study focused on 4,387 fifth grade students in Birmingham, Ala., Los Angeles and Houston. “We wanted to find out if certain schools look heavier because of the composition of the schools—meaning kids at higher risk of obesity like African American girls or Hispanic boys cluster within certain schools, or if there was something structural in the school that influences BMI, like the facilities or programs offered,” explains Richmond.
When the researchers used multi-level statistical modeling tools to tease out the effects of physical activity programs, nutritional resources and school-level median household income, they found that school income is inversely related to girls’ BMI. That is, fifth grade girls tend to be heavier in lower income schools.
The researchers did not observe a similar link among boys, nor did they find connections between average BMI and factors such as physical education (PE) class time, regular recess, nutrition curriculum and availability of brand name fast food items in the school cafeteria. The researchers also factored in parents’ BMI.
“Once you accounted for the school composition and parental BMI, there was no variability left. The parents and home are so strikingly important [in determining BMI] that schools may not be able to mitigate against those influences,” says Richmond.
One caveat is that the way school programs were measured could influence the seeming lack of impact. For example, if a school reports daily PE classes, but the students are not active during this time, it would not be accounted for in the PE measure.
Which brings up the question—do schools matter in the anti-obesity effort. Or, as Richmond poses, “Where do schools fit in the hierarchy of families and neighborhoods?” Should so many anti-obesity efforts be focused at the school level?
The answer might be a more comprehensive effort that cuts across school subjects. An analysis of the Planet Health program, a curriculum developed by the Harvard School of Public Health in the 1990s, suggested the interdisciplinary intervention reduced girls’ BMI. “It’s one of the few studies to document change in BMI outcomes,” confirms Richmond. The integrated program included topics related to healthy dietary and physical activity embedded in all school subjects from math to social studies.
Now, Richmond and other researchers are undertaking a study of a prevention effort that includes the Planet Health curriculum plus before- and after-school programs and environmental changes to see how they collectively affect BMI. Preliminary results are promising, indicating a decline in BMI in participating schools.
As for what’s ahead, Richmond and her colleagues are now looking at the influence of schools and neighborhoods in the same study in an effort to understand which one has more influence on health outcomes, including BMI. They hope to guide those developing obesity intervention and prevention programs to target the most effective locations.