First thing that comes to mind is... CHEESE. Thanks again WI! Anyhow.. 165lbs for a 5'11 frame sounds a bit light to me. I suggest you get to know about the 3 body types - ectomorphic, mesomorphic and endomorphic. Or as someone like me might say.. skinny, jock or tubby. I can only assume that because you're ok with a whoppin 155lbs, that you're a ectomorphic type.

If it's weight you're trying to lose and you want to do it quickly, I suggest the Adkins diet. No, not because you're friends tried it, but because it works. Bonus: you get to eat lotsa cheese!

You'll get to eat right, lose weight and exercise isn't a bad idea either.

Good luck!