Obesity among preschoolers not declining after all, experts say

A study last month reported a 43 percent decline in obesity among preschoolers, but experts are now questioning the claim.

The study was published in late February in the Journal of the American Medical Association. It cited changes to the federal nutrition program for low-income women and children, the elimination of trans-fats from fast food, more physical activity in child-care programs and declining consumption of sugary drinks as the reasons for the drop in poundage.

Obesity experts now suggest that the findings were a fluke, especially given that no previous studies showed such a significant decrease in obesity among preschool kids.

"You need to have a healthy degree of skepticism about the validity of this finding," Dr. Lee Kaplan, director of the weight center at Massachusetts General Hospital in Boston, told Reuters.

Kaplan went on to say that these children, ages two to five, have not drastically changed their behavior in a way that would explain these results.

The 43 percent headline is based off of the obesity rate from 2003-2004 (13.9 percent) compared to that of 2001-2012 (8.4 percent). By rounding the figures, researchers at the U.S. Centers for Disease Control and Prevention came up with the 43 percent statistic. However, in part due to the small sample size of participants, there was a large enough margin of error that the actual rate from 2003-2004 could range between 10.8 percent and 17.6 percent, and the 8.4 percent rate in 2011-2012 reported could range from 5.9 percent and 11.6 percent.

The CDC scientists concluded "there have been no significant changes in obesity prevalence in youth or adults between 2003-2004 and 2011-2012."

A CDC spokeswoman said the lead author of the JAMA study, Cynthia Ogden, "is not doing any media interviews," but tried to restore the study's validity by saying that "the sample size is somewhat small so the (ranges of values) are a little wide."