The Caloric Calculator
After more than a decade’s efforts to address the childhood obesity epidemic, we are beginning to see the first signs of declines in obesity rates in several cities and states across the country, many of which instituted a comprehensive range of policies and programs. While these “bright spots” are encouraging, it can be very difficult to pin down the exact set of actions that brought about these changes that should be promoted and replicated elsewhere.
This speaks to one of the biggest challenges in childhood obesity prevention at the population level: that is, the lack of a common metric to compare programs of various configurations. Even though we know we need to get kids to eat better and exercise more, how do we compare the effectiveness of, for example, taking junk foods and sugar-sweetened beverages out of schools versus adding PE classes?
The Caloric Calculator aimed to address this critical knowledge gap. Building on our earlier work on the energy gap, we conducted a comprehensive literature review and developed the Average Caloric Impact (ACI) metric to compare various interventions. The ACI summarizes a program’s impact on the population’s energy balance by estimating the difference it makes on calories consumed or calories expended for an average child on a daily basis. In order for an intervention to have a large impact on childhood obesity, it has to have a wide reach, long enough duration, good intensity (especially when we are talking about physical activity), and strong evidence of effectiveness.
For example, adding 10 minutes of PE a day would be impressive progress for school health, but such a policy would only impact children during the ~180 days of schools in a calendar year. For middle school students, this translates to an average reduction of 14 kcal/day impact on energy balance. On the other hand, an intervention to cut TV viewing time every day has the potential to affect the same child with a reduction of nearly 106 kcal a day.
It can be easy to lose sight of the magnitude of the impact of any one policy without a common metric for comparison. We hope that the Caloric Calculator provides a mechanism to synthesize the newest evidence on childhood obesity prevention and a springboard for prioritizing and comparing the wide range of possible interventions. Further, with its user-friendly interface, we hope that the tool allows for better communication among practitioners, teachers, parents, researchers, and policymakers alike.
— Y. Claire Wang, MD, ScD, and Amber Hsiao, MPH, Mailman School of Public Health, Columbia University
AJPM Article: Wang YC, Hsiao A, Orleans CT, Gortmaker SL. The Caloric Calculator: Average Caloric Impact of Childhood Obesity Interventions. Am J Prev Med 2013;45(2):e3-13.