And let's be clear: It's not enough just to limit ads for foods that aren't healthy. It's also going to be critical to increase marketing for foods that are healthy.

I think that mentoring is such a critical part of the role I can play in my position. I see how little bits of exposure and big bits of exposure really change my girls significantly, and I want that for more girls around the country and the world.

My sense is that being a First Lady is a full-time job, but I'll know more when the time comes.

Exercise is really important to me - it's therapeutic. So if I'm ever feeling tense or stressed or like I'm about to have a meltdown, I'll put on my iPod and head to the gym or out on a bike ride along Lake Michigan with the girls.

There are still many causes worth sacrificing for, so much history yet to be made.

I've always been a closet jock. With exercising, the more you do it, the more you get into it. And the more you see results, the more you're pushing for the next level.

Moving [to the White House], whatever stresses would be on my husband and me, we could handle; we are grown-ups. But it wouldn't be until the day that my kids came home and said to me, "I like it here," that I'd feel like I could breathe and know that we're all going to be okay here.