The thing about obesity is that hardly anybody wants to be obese, yet a lot of people are indeed obese. Or maybe there is like a secret club that is into "extreme body modification." Maybe people get to a point where they say, "you know, I could stretch my earlobes out to the size of hubcaps, but I think I'm gonna weigh 600 pounds instead."
I have personally been both in "pretty good shape" and "dang near obese" I can tell you with confidence that being in good shape is way better. Just clench your butt cheeks while you're sitting there, even that is exercise.