Is there a chubbiness threshold at which you create a "barrier-to-entry" so to speak?

I hear guys say that they consider it a numbers game, and that you should always be in-state and running game on every girl you meet. If a girl is beyond the size at which you would take her home, do you still run game on her as practice, and then not pursue it even after you've won her over? Or does she just not even pop on your radar?

(BTW, just for clarification, I'm a guy whose been overweight for a long time, but is getting back in shape because, quite frankly, I'm not attracted to the chubby girls that are most available to me at the size I've been. I want to be sleeping with the women I'm most attracted to, so I'm improving myself. Just want to know how the rest of you guys approach it.)