What’s the deal with David Miller’s incredible shrinking waistline?

The secret to Miller’s recent deplumpage is a largely vegetarian diet that basically excludes everything fun and fattening. Like Bill Clinton, who famously gave up Big Macs, Miller was a fast-food junkie. Quarter Pounders with cheese, he says, got him through the 2003 election—and left him pushing 250 pounds. Since then, he’s cut out his daily McD’s fix. In fact, he’s cut out all unhealthy fats and refined sugars. The relentless wine and cheese affairs that come with being mayor require steely willpower, but he resists the call of the canapé by filling up on five protein-rich meals a day (a typical weekday lunch might include chickpea-lentil casserole, plus a handful of almonds). He also now works with a trainer twice a week and runs an average of 12 kilometres three or four times a week. Lately, instead of food, he’s been devouring running books in preparation for a half-mara­thon on September 27. All told, our lean, mean mayoral machine has shed more than 50 pounds. No doubt a Miller Lite campaign slogan is in the works for 2010, though it’s probably safe to assume “Everything you want in a mayor, and less” won’t make the cut.

• Question from Angie Stephanopoulos, Riverdale