Well no, I don't believe there is a such thing as being obese and healthy. I know if I were obese, I wouldn't have as much speed and stamina as I do now. Essentially, being obese means you're out of shape.
That being said, it's about how one feels about him/herself. It's just that not many people find obesity very...attractive. How many people do you hear say they want to be obese? I guess you can say they are discriminated against.