It’s not a headline you see very often: Childhood obesity on the decline. But, as my Washington Post colleague Rob Stein reports, that’s exactly what’s been happening in New York City. There, the childhood obesity rate has dropped by 5.5 percent over the past five years according to new federal data. The drop cuts across all demographics and socioeconomic groups and has been particularly dramatic among younger children:

This is counter to some national trends, where childhood obesity has risen among older children after a slight drop in the early 2000s:

At least some of the explanation for the decline looks to be specific to New York City, notes the report from the Centers for Disease Control and Prevention. The Big Apple has a particularly aggressive approach to public health, using strategies such as offering financial incentives and banning the use of food stamps for soda to encourage New Yorkers to make healthy choices.

Perhaps more important, the city has implemented some basic reforms to fight childhood obesity that we know work: New policies require schools to provide more nutritious meals to students and to increase kids’ physical activity and cut down the time they spend sitting in front of computer screens.