From the AP, via msnbc.com:

Oregon Has Lowest Rate of Child Obesity
Unlike other states, obesity fell significantly from ’03 to ’07

Our great state of Washington is tied for third lowest with Minnesota; the South has the highest rate of obese kids. Here's some more specific info about the study.

Everyone would love to duplicate Oregon's success in defattening its children, but...

It’s unclear how much states can overcome the effects of poverty, race and family history—all of which have complex links to obesity.

Black and Hispanic young people in the study were twice as likely as whites to be overweight or obese, even when the researchers took into account other risk factors like inactivity and poverty.

Oregon is 90 percent white.

...In a separate paper based on the same data, Singh found that a child living in a neighborhood with unsafe surroundings, poor housing and no access to sidewalks, parks and recreation centers had 20 to 60 percent higher odds of being obese or overweight.

I did not know until this moment that Oregon is so mighty white.