If you are already very lean, you need to chow down. Don't be counting egg whites and shit. Concentrate on improving your squat, dead, bench, row, chins, and overhead press (all barbell/no machines) then eat everything in sight. Chow down, if it's a double Whopper or QPounder so be it - don't eat fast food and junk all the time but don't worry about it, tons of muscle can be put on eating less than ideal diets and frequently it is a lot harder to gain eating super clean (just hard to get that many clean calories in). If you find youself getting too fat, drop back a bit (of course some is to be expected in bulking). Once you lean out, chow again and push the weights up.