Guys, when you see a girl...?

Is the first thing you notice her weight? And if so, does that play a part in if you are attracted to her? Do you ever talk to/hit on/etc. a girl who doesnt have a "smokin' hot body", but isnt fat either? I'm just wondering, because i've talked to a lot of girls, and about 85% of them dont even consider a guy's weight a factor.