Dieting Commercials

Why is it on Lean Cuisine commercials, the women on diets are women who don't need to be on a diet (skinnies)? Isn't that sending the wrong message?

On the other hand, I love the new Slim Fast commercials with the curvy women and the slogan "Find Your Right Size." These women are dieting and losing weight, but it's not about becoming really skinny. It's about being healthy. Isn't that a better message to send women?