Rates of obesity among preschoolers declined in 19 of 43 U.S. states and territories examined in a Centers of Disease Control and Prevention study reviewing data from 2008-11.

The report revealed what it called “small but significant” declines in obesity among low-income preschoolers but said continued prevention efforts are needed to sustain the trend and prevent childhood obesity.

“This is great news,” said Lorelei DiSogra, vice president of nutrition and health for the United Fresh Produce Association, Washington, D.C.

The CDC said it could not attribute changes in the obesity prevalence to any specific factor. However, the research report said that federal policy changes such as the alignment of the Women Infant and Children food package to the Dietary Guidelines for Americans might have led to improved diets among low-income preschool children and their families. Beginning in 2008, women participating in the WIC program received a voucher to purchase fruits and vegetables.

WIC changes may have helped trim obesity among preschoolersThat long-sought improvement in the U.S. Department of Agriculture's WIC food packages, along with a greater percentage of moms participating in WIC who are breastfeeding, both seem to be factors in reducing the incidence of child obesity, said Doug Greenaway, executive director at National WIC Association, Washington, D.C. “We are happy we finally got those changes (to the WIC food package) and we believe that has had a significant impact,” he said. “We are able not only to educate about eating healthy, we’ve got a food package that reinforces those educational efforts.”

The CDC report also said reductions in obesity among preschoolers may also be credited to local and state initiatives that focus on the implementation of nutrition and physical activity standards for early care and education programs.

The study used measured weight and height data from about 11.6 million low income children from 2-4 years old from 40 states, Washington, D.C. and two U.S. territories. The CDC said obesity among preschoolers was defined as having a body mass index of greater than the 95th percentile of CDC growth charts.

The results of the survey showed the states and territories with the largest absolute decreases in obesity prevalence included Florida, Georgia, Missouri, New Jersey, South Dakota, and the U.S. Virgin Islands. The CDC said 20 states and Puerto Rico showed no change, and obesity prevalence increased significantly in Colorado, Pennsylvania and Tennessee.

Despite the decreases in some states, the survey said obesity among low-income preschool children remains high. In 2011, the CDC said the prevalence of obesity for all contributors to the survey as 14.4%, or about 4% points higher than in the early 1990s. CDC statistics show that children who are overweight or obese as preschoolers are five times as likely as normal-weight children to be overweight or obese as adults.

The prevalence of obesity among states/territories in the study ranged from 9.2% to 17.9%, according to the report. Ten states/territories had an obesity prevalence above 15%, with the high obesity prevalence in Puerto Rico at 17.9%. Six states/territories had an obesity prevalence of less than 12%, with the lowest obesity prevalence in Hawaii at 9.2%.