I love studies like this that examine things that I'm interested in. I wonder how these attitudes play into disordered eating, workout obsessions, how males and females treat each other, the effects this has on a relationship, the cultural context etc.
This study was done in 1985 and is super popular. People replicate it all the time and look at differences between generations, cultures etc.
Basically, they asked men and women to note where they believe they are currently on the body scale, then note where they would like to be ideally, and what they think is attractive to the opposite sex. They also asked them to mark on the opposite gender's chart what they find attractive.
It's interesting to me that men think they should be bigger/bulkier and women think they should be skinnier. I wonder how much this has changed in the past few years. I think there are more guys trying to be skinny lately as well as the pressure to be really muscly so it's kind of divided (Note all the nasty skinny jeans men wear lately. I guess they're just helping with survival of the fittest.)
Click on the figure to be able to read it.
Fallon, A. E., & Rozin, P. (1985). Sex differences in perceptions of desirable body shape. Journal of Abnormal Psychology, 94, 102–105.