How do I know if I have an accurate body image?

Stand in front of a mirror. Naked. Without sucking in your belly. Now draw an outline of your body shape, both from the side and front views. Ask a partner or close friend to look at the shape you drew and tell you—honestly—if that's approximately what your body looks like. (Your clothes can be back on at this point.)

This is just a quality-control check to make sure you have an accurate self body image (those with eating disorders have very distorted body images, making it an obstacle for getting back to a healthy weight). This might be the first time you've ever had to articulate things about what your body looks like—and that's good.

For some of you, this assignment may feel natural, but for most, the exercise is as uncomfortable as a coach-class airline seat. I'm having you do this not to benefit the neighborhood peepers, but for other reasons.

First, I want you to realize that I'm going to be emphasizing healthy weight—not fashion-magazine weight, not featherweight. Healthy weight. And I think that means you have to start getting comfortable with the fact that every woman isn't as light as a kite and every man won't have the body of Brad Pitt. Where you want to be may not be exactly where your body wants you to be. I'm not saying you need to accept a belly that looks like four gallons of melted ice cream, but I want you to get closer to your ideal health—and that means physically and emotionally.

Second, I want you to look at your body. Really look at your body, as it genuinely is.