Honestly, I think women don't mind as much as guys "generally" do. Women generally don't care if a guy is bigger, or a little on the chubby side. Women care about whether the guy takes care of himself and more importantly whether or not the guy takes "care" of them. Also all women are different so what attracts them to you will differ, physically, mentally, spiritually, etc. I've seen some VERY, non attractive guys date attractive women before.
I agree though, while you can be preferential, being picky while not expecting a girl you like to be picky is asking for trouble. To me it comes off as a form of self-hate, if you can't relate to anyone in the same situation as you. Not saying "Ooh you're overweight, you have to hook up with that overweight girl, hook up with whoever you want to. Just give people the same chance you'd want given to you.
I'd tell anyone hating on you because you're overweight or big to take a hike, but still be concerned about trying to make healthy lifestyle decisions. Being healthy and fit, isn't "needed" to attract anyone, but just like for a woman, it doesn't hurt either.