I've been on dates with fat women, and it's hard to feel anything. I don't feel anything. I'm giving them an honest shot sometimes but I feel no attraction.
I can tell that they go through life feeling no affection from people. It's a little sad. When I meet even a modestly attractive woman from online dating, the first thing she does is peck me on the cheek. That's what she's used to: affection. If I meet a woman who isn't that attractive, typically they might give a nod of the head or a handshake to start the date, which I assume is because they're used to that coldness.
I went out with a big girl a while back. She only discussed intellectual topics with me. I might be over-interpreting, but I couldn't help but think it's because she's never been able to relate to people emotionally and discuss fun stuff since nobody wants to have those conversations with a big person. Attractive girls are more likely to laugh, smile, talk about travelling, family, etc rather than how policy makers can have more influence over the application of international human rights law, because -- I think -- they're used to the privilege of being allowed to be emotional creatures.
ETA: This other girl I was talking to a while back off eHarmony, then stopped talking to, she was moderately big as well but with a few redeeming features (decent facial attributes, nice rack). Same issue, she kept talking to me about intellectual topics, her classes, organic chemistry (which I have not thought about since 2003), and how more people need to value intellectual aspects and she can't meet anybody as enthusiastic as she is. She told me her grade: 93%. I can't remember the last time anybody told me their grade. She did not talk much about personal issues.