Seriously, im 5 10 and 125 pounds, i have a nice 6 pack, and some tone in my muscles(running, and being fit) and im ok with that. Besides, if you're worried about looking good to get a girl, its not worth it, any girl that would only date you because of how big you are, isnt worth it anyways. And if you wanna get big to be able to fight, thats not worth it either, cause more than likely, you're goign to get your ass beat anyways...To quote chris rock
"You got pecs? I got tec's"
(tec-9 for those that dont get it)
Basically, just be happy with who you are. I know i am, and thats what its all about.