Well for me I don't think there's an age factor. Even as a teen I preferred plumper girls. One of the girls I dated in high school was 4'11" and though she would never tell anyone the actual number on the scale I'm guessing she was somewhere between 250 and 300 at the time. Even then I worried about her health, but to me she was gorgeous. I've never had much success with weight loss before now though, so I've never had to deal with this confusing double standard I apparently hold.
Another crazy thing - while I am still not attracted to the real skinny girls or the over the top body builder types, the somewhat muscled women have become more and more attractive to me the more fit I become. Before this journey began I would never have been attracted to people with a Jillian Michaels type body, now I find her and others built like her rather hot (still not as much as a chubby girl though - hehe). For me it's happening with men too. I used to be kinda grossed out by men built like Vin Diesel. The other night I actually said "you know, he's kinda cute there". ACK!! What's happening to me? LOL