For a long time ive been eating chicken breasts like crazy and really cant say its responible for any gains, same with tuna. But with steak it seems thats were im getting my gains ive actually tried something before. 2 weeks with chicken and tuna as a main protein source and 2 weeks with mainly steak protein source. i got little to nothing with the tuna and chicken and actually a few pounds with the steak diet (Lean mass). The other day a pro bodbuilder tolds me "Have you ever seen a big chicken?" and "Have you ever seen a small cow"? lol makes sense though.