McCardle and Ambinder are having a back-and-forth over obesity: Megan interviewed Paul Campos who called obesity a fake problem, Marc –who is writing an article on waistline politics – responded, Megan fired back, Ambinder followed up and Megan went one more round. Here's Marc:

McArdle is right that it it's not fair for government to lecture people about weight loss and exercise, but she's right for the wrong reason: policy choices -- ag subsidies, zoning laws, education and budget priorities -- create a flow that, absent any intervention, are sweeping many young kids, particularly poorer kids of color, into obesity. Government's role isn't to scold; it's to make better policy choices. She's wrong about the interventions, too: some, like a physical education project in Somerville, Mass., seem to be working. Taking fast food vending machines out of schools and weighing children at least once a year has arrested the obesity growth rate in Arkansas.  Nationally, the obesity growth rate also seems to be be slowing.

Fallows sides with Ambinder. Like Megan, I have a visceral dislike of being told by government how to live my life.

(Photo: Matt Cardy/Getty.)