"These are the kids you expect least to change," said Gary D. Foster, director of Temple University's Center for Obesity Research and Education, who chaired the study of 4,603 students in 42 middle schools around the country, including six in Philadelphia. He and others speculated that the decline might be greater in the general population.
Though good news, the finding was not what the researchers were looking for. Their primary goal was to determine whether an intensive, school-based effort to decrease calories and increase physical activity could make a dent in the combined prevalence of children who are overweight and obese, key risk factors for Type 2 diabetes.
In fall 2006, they divided the schools into two groups. The sixth graders in half the schools participated in the program; the other half were controls. When they were reassessed as eighth graders in spring 2009, the rate of overweight and obese students had dropped by nearly the same 4 percent in the schools that got the intervention as in those that did not.
However, the researchers did find notable differences among subgroups and in specific measures. For example, body-mass index scores, average insulin levels and the percentage of students with the largest waists - all risk factors for Type 2 diabetes - were significantly better in the intervention schools. All the effects were even stronger among students who were overweight or obese when they began the program in sixth grade. That group, in fact, had 21 percent lower odds of being obese at the end of eighth grade compared with the controls.
Foster and colleagues presented the findings Sunday at the association's annual scientific meeting in Orlando. Underscoring their significance, the results were simultaneously published online in the New England Journal of Medicine.
