Before the nation's Food Nanny guilt-trips you into ditching boxed dinners on a frazzled night, know this: The first lady profited from cheese dust before she was against it. In the new issue of Cooking Light magazine, Michelle Obama takes another sanctimonious stand against processed foods. The occasion of this latest hectoring is a month-long celebration of the fifth anniversary of her Let's Move initiative. This time, she spins a slickly crafted tale of how her former personal chef challenged daughter Malia several years ago to turn a block of cheese into powder. "She sat there for 30 minutes trying...