I do not find women who exceed a certain weight-to-height ratio sexually attractive.
I just don't.
My tastes in this regard are probably a lot wider than, say, a Parisian fashion designer, but still there's just some body types I don't find sexy, and that's just how it is.
(Just for completeness' sake: I tolerate skinny a lot better, but there is a point where skinny becomes anorexic. And I mean real anorexia, not "OMG that celebrity is anorexic and I hate that she's famous and thin". Skeletal isn't my bag, either.)
How did I come to prefer what I prefer? I dunno. How do people become gay or lesbian?
I doubt, however, that it was society drilling into my brain that "thin is sexy" repeatedly.
For me, at least, what I find sexy is just there in my head. And anyone trying to tell me that I should find Person X also sexy is going to succeed or fail based on what triggers the old lizard brain, not any inherent fairness or unfairness in my perceptions.
So every once in a while someone says something similar to "well, they should add more realistic body types to comics heroines, so that there's some normal-weight people in there." And then some other people say, "Ew, I don't want to see average or heavy-looking superheroines, that's not sexy." And replies to THAT sometimes go like, "You're just brainwashed by society into thinking that these scrawny women are sexy! If the media had more heavy sex symbols, heavy would be sexy!"
Nnnnnnnnoo. I don't think so.
Look, it's rare, but there've been points where heavy meets sexy. Cameron whatsername on that lawyer show, The Practice. A host of Jerry Springer episodes titled "I LOVES MAH FAT WOMANS" or something like that. There's fat porn. And to some that is sexy, but thinking about it makes me shudder in proportion to the weight involved. Because the covers of magazines like Maxim or FHM feature taut, bikini-clad women of within a certain body mass index, I can infer that a majority of people think in a similar fashion to me. Yes, heavy people fall in love, have relationships, I've seen it in person. Lucky them, that they found people that find heavy attractive. But there's a reason why sex symbols, models and movie stars tend to be thin, and it's not a conspiracy of the fashion designers and Hugh Hefner.
Not like I want to deliberately hurt anyone's feelings by saying "you're fat, so I don't find you sexually attractive", but there it is, and maybe you're a wonderful, beautiful soul under that cellulite, but if you're overweight, that's just going to limit how deep our relationship goes. Whether that's fair or not, that's how it is. And you can't impose different standards for attractiveness on me just because we should all be all understanding and not judging people by their looks. Adding, what, fifty pounds to the physique of many a superheroine would make them that much less appealing to me.
Tell me - would you want a 250-pound Nightwing running around? Or better yet, a 350-pound Guy Gardner? His ring's power comes from his mind, so he doesn't have to actually keep fit, he could scarf Cheetos down constantly inbetween buying buckets at the KFC...