Despite numerous federal and statewide efforts to reduce childhood obesity over the past decade, more young males are now considered obese than at the turn of the century, while the overall rate of childhood obesity in the United States has remained steady, according to an analysis published online today in the Journal of the American Medical Association.
Researchers examined a representative sample of data from roughly 4,100 children, from birth to 19 years of age, taken from the 2009-10 National Health and Nutrition Examination Survey. The researchers recorded each child's height and weight, then examined overall body mass index trends.
Among children ages 2 through 19, 16.9 percent overall were considered obese (they had a BMI above the 95th percentile of the BMI-for-age growth charts) in 2009-10. In total, 31.8 percent of children ages 2 to 19 were considered either overweight or obese that year.
The researchers also discovered significant differences in obesity between children of different races and ethnicity, which, given socioeconomic factors, shouldn't come as much of a surprise.
"In 2009-2010, 21.2 percent of Hispanic children and adolescents and 24.3 percent of non-Hispanic black children and adolescents were obese compared with 14.0 percent of non-Hispanic white children and adolescents," the researchers write.
Childhood obesity increased throughout the 1980s and 1990s, according to the Centers for Disease Control and Prevention, but leveled off over the past decade. In the 1999-2002 NHANES, 16 percent of children were estimated to be obese.
The researchers also discovered no significant difference between the rates of overall childhood obesity from 2007-08, when 16.8 percent of children were considered obese, to 2009-10 (16.9 percent).
They did, however, discover a significant increase in the overall trend of obesity for males ages 2 to 19 over the past decade. (Females had no such increase.) Based on regression models, they attributed the rise largely to a "significant change in BMI" in 12- to 19-year-old males in that time span.
They note in the analysis that studies from other countries have noticed similar trends, with young males experiencing a much more significant increase in obesity than females.
Overall, they say it's difficult to compare obesity rates between the U.S. and other countries, due to discrepancies in how each country defines and measures obesity. (The U.S. uses BMI, which the authors dub "an imperfect measure of body fat."
"Nonetheless, estimates of childhood obesity in the United States tend to be higher than in other countries," they write.
With that said, childhood obesity may still be on the rise outside the U.S. With the data suggesting that the U.S. childhood-obesity rate has begun to plateau, the researchers hope to figure out what's sparked the change.
"Some have suggested that the prevalence of obesity among children will reach 30% by 2030, but the data presented herein suggest that the rapid increases in obesity prevalence seen in the 1980s and 1990s have not continued in this decade and may be leveling off," the authors conclude.
"More research is needed to understand why these changes may be occurring."
There's no understating the importance of the obesity rate leveling off in the U.S., given the enormous estimated cost of health problems related to obesity. In 2008, health problems tied to overweightness and obesity cost the U.S. an estimated $147 billion, according to the CDC.
Want all the latest K-12 sports news? Follow @SchooledinSport on Twitter.