Recently published reports show declines in the rates of obesity among children in both urban metropolises and smaller cities and towns. Though preliminary and confined for the most part to three geographical regions—Los Angeles, Philadelphia, and New York City—the data suggest that one of the most challenging epidemics to affect young people—17 percent of children under 20, or about 12.5 million children in the United States are obese according to the Centers for Disease Control—may be reversing itself, slowly.

Experts speculate that perhaps nutrition education and exercise initiatives are producing results, as the issue is now part of the national conversation, having been championed both by educators and physicians who have gradually waged war on in-school soda machines and deep fryers and by high-profile individuals like First Lady Michelle Obama.

A closer look, however, reveals that although dense urban centers like New York, Los Angeles, and Philadelphia are showing drops of five and a half percent, three percent, and five percent respectively, the weight loss is concentrated among white students from more affluent families. Some 20 percent of African-American children are obese while only 12 percent of white children are; among girls, 25 percent of African-American girls are obese while only 15 percent of white girls are. In New York City, for example, the rate of obesity among African-American students in kindergarten through eighth grade dropped only 1.9 percent from 2007 to 2011, while in the same time period and age group, the rate among white students declined by 12.5 percent.

What accounts for the disproportionality of the figures? Is it limited access to healthy foods in the food deserts of our cities’ low-income neighborhoods? Is it that many weight reduction efforts center on a single day designated to build awareness about choosing and preparing healthy foods and exercising regularly, rather than on the long-term programming and systematic policy changes that many scientists encourage? Is it the ubiquitous corner store where kids buy sugary, salty, and fat-laden snacks and drinks for mere pennies?

It seems the implication for initiatives such as Junior Leagues’ Kids in the Kitchen, currently underway in 200 communities in four countries, is to stay the course, to measure results, and to continue to chip away at the epidemic, with special attention to the neighborhoods where the problem seems most intractable.