The rate of childhood obesity in the U.S. rose by 10 percent between 2003 and 2007, but in Maryland that rate of increase was just two percent, according to new study that shows wide variations in obesity rates by states.

About 13 percent of Maryland children ages 10 to 17 were obese in 2007, a slight increase from four years earlier, the study found. But it was still below the national average of a little more than 16 percent.

The percentage of overweight children in Maryland was 29 percent, a decrease by nearly four percent, according to the statistics published online in the Archives of Pediatric and Adolescent Medicine.

We've known for years that children across the country are getting fatter. But this study zooms in on the huge disparities that exist by state and region and suggests that if the country is going to fight the obesity epidemic as everyone from local schools to Michelle Obama would like to do, zeroing in on these variations will be key. 

Nationwide, more than 16 percent of American children are obese and 32 percent are overweight, with rates highest for states in the Southeast. The highest was Mississippi, where more than a fifth of children are obese. Oregon had the smallest percentage -- just under 10 percent of children were obese. It was the only state that had a significant decrease over the four-year period.

African-Americans and Latinos were twice as likely as whites to be overweight and obese, even when researchers adjusted for issues such as poverty and inactivity. And the increases for girls in some states were dramatic. For instance, in Arizona and Kansas the obesity rate for girls doubled, the study found.

The findings, gleaned from statistics of more than 44,000 children, mirrored geographic differences among adults. For both adults and kids, the Southeast had the highest obesity rates and the Western states had the lowest. 

Prevention programs should focus on reducing these disparities and should include behavior interventions -- getting kids more active and cutting out the TV time -- as well as policy measures that get at the broader societal factors for the obesity epidemic, the authors write. 

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