I don't find big people attractive at all but now you've asked, I don't know why in particular, I just don't. I think of all the photo's are awful but then a lot of people don't find members of other races attractive. Not due to the colour of their skin but they just don't and can't really explain why. Maybe it's just the views of this society, whereas other find skinny people really ugly. Or subconsciously, fat people very generally to have more health issues than those who are just slim (not anorexic) so maybe it's part of the natural instinct of passing on genes and looking for a mate.