By Vanessa Rancano, freelance journalist, NPR |

As researchers have searched for ways to explain the childhood obesity epidemic in the U.S., many have posited that a child’s race or ethnicity alone can put them at greater risk of becoming overweight or obese.

Kim Eagle, a professor of internal medicine and health management and policy at the University of Michigan, was skeptical of this thinking. His hunch was that poverty was a much more important part of the equation.

And he saw an opportunity to parse the connections between childhood obesity, poverty and race in Massachusetts, where public health officials have been collecting race, body mass index and other data on about 112,000 students from about 70 of the state’s school districts. Eagle and colleagues decided to compare those data to students’ eligibility for free school lunch programs, an indicator of poverty, to find out what predicts whether a child might become overweight or obese.