I have thought on this a lot, and I think a large part of that is standards. It's not, "I think I'm fat", it's, "I think I'm too fat for someone like her."

For guys, there can be pressure to be or at least look physically fit and while a lot of girls and guys like the fit look, they might actually prefer something else in a partner. Now, I'm not the most in shape guy ever, though I do exercise and have a naturally muscular build, but I can't remember the last time I saw my abs. My stomach doesn't even hang over my belt, but there is some jiggle.

What's surprised me though, is the number of times past girlfriends have made some kind of comment along the lines of, "don't get any more muscular" or "don't get any leaner" followed by "I like putting my head on your stomach". <shrug>

In my experience, girls that are into me like strong arms, shoulders, chest and legs, but they want some cuddliness too. Most men have at least a bit of a belly and a lot of women don't mind that.

People are into all kinds of stuff. I used to know a guy who looked like he'd have no problem (but not a huge amount of success either) with girls who once told me that he was into fat older women and he made it pretty clear that when he said "older" he meant old and when he said "fat" he meant fat. I didn't believe him until he went on a trip and never made his flight. Turns out he'd shacked up with such a woman when he stopped to get a quick beer before heading to the airport and was so enthralled they spent three days in bed together. Personally, yuck. But y'know . . . people.