SUNDAY, June 27 (HealthDay News) -- School-based efforts at
better nutrition, more exercise and improved education about
healthy living can help kids who are most at risk for obesity keep
the weight off, compared to children in schools without such
programs, a new study suggests.
But the program failed to reduce the overall numbers of
overweight and obese schoolchildren -- those numbers fell by 4
percent over three years whether the 42 middle schools in the study
had such initiatives or not, the researchers report.
"The intervention, surprisingly, did not result in a [population-wide] reduction in overweight or obesity," said lead researcher Gary D. Foster, a professor of medicine and public health and director of the Center for Obesity Research and Education at Temple University, Philadelphia. "What's surprising is that the control group improved as well," he said.
The school-based initiative didn't seem to have much of an
impact on children who were not already overweight or obese by
sixth grade, the team found, but it did impact children who were
already having weight troubles by that grade level.
For those kids, "there were small [weight-loss] effects of about
3 percent. Although that's small, it's enormous given the rates of
obesity in this country," Foster said. "This was an unexpected but
fortunate finding -- that we are actually impacting the kids at the
The findings are slated to be presented Sunday at the annual
meeting of the American Diabetes Association in Orlando, and they
are also being simultaneously published online in the
New England Journal of Medicine.
For the study, Foster's team randomly assigned more than 4,600
students from the 42 schools to a diet, exercise and information
program, or to a program where only their weight and height was
assessed. The study targeted schools with high levels of minority
children, because studies have shown that they are at especially
high risk for obesity.
Children in the program were offered healthier food choices
throughout the school: in the cafeteria, at snack bars and in
vending machines, and during class events. These included:
lower-fat, higher-fiber foods; more fruits and vegetables; and an
emphasis on water, low-fat milk and drinks with no added
In addition, there were longer, more intense periods of physical
activity for the schoolchildren, and activities and awareness
campaigns to promote healthy living.
The researchers found that children who were already obese at
the start of the program lost a significant amount of weight, as
indicated by reductions in waist size, compared with other
In fact, children in program schools who were either overweight
or obese in the sixth grade had 21 percent lower odds of being
obese by the end of eighth grade, compared with students in schools
without such initiatives. The program also lowered levels of
fasting insulin, a key indicator for diabetes risk, the researchers
However, children from both types of schools had the same
average blood sugar levels and the same percentage of students with
elevated blood sugar, the study authors noted.
Foster said that it is intriguing that the rate of overweight
and obesity dropped by 4 percent regardless of whether the school
had an anti-obesity program in place or not. "This is potentially
good news -- that the rates of childhood obesity appear to be
declining [naturally]," he said.
Several factors may be at work in this decrease in overweight
and obesity even among those children, Foster noted, including
children putting more attention on their weight. Just the fact that
the researchers were measuring children's height and weight might
have made the youngsters more weight conscious, he added.
"Something has changed and we've got to figure out what that something is," Foster said.
Dr. David L. Katz, director of the Prevention Research Center at
Yale University School of Medicine said that "the results of this
study are open to interpretation, and thus conclusions are apt to
reside in the eyes of the beholder."
People who don't put much stock in school-based interventions
will point to the lack of an effect overall, he said. "However,
those who perceive value in school-based interventions -- and I am
among these -- will focus on the obvious pattern in an array of
secondary outcomes, including reductions in body fat and insulin
levels, which in turn would be expected to reduce diabetes risk,"
And the program's effect on obese children is important, Foster
"There is a strong signal here that this [program] can make a difference," Foster said. "If we can reduce the risk of type 2 diabetes in children by reducing the rates of obesity and reducing waist circumference, that's an important outcome," he said.
There's more on childhood obesity at the
U.S. National Library of Medicine.