Funny you should mention that.. because when I was scanning the crowd for skinny girls, I saw a few skinny guys, but they were in a group and were not americans, so I did not want to embarrass the guy in front of his friends...
I think doing it with guys would be harder actually, only because girls are not supposed to be stronger than guys in societal norms.. I could put up a casting call for skinny male models, but i am 1 for 6 in getting them to show up.. they cancel left and right on me... If I see a likely one in kentucky when I film again, I will... but don't be surprised if he wants to be masked,... but hey, can't hurt to ask.. so I will