You need to look into muscle mass supplement (protein shake) or pills and incorporate that with what you're eating if you're trying to get mass (more muscle mass)

this website is awesome
http://www.bodybuilding.com/

The guys I box with take this stuff
http://www.bodybuilding.com/store/bsn/epozineo2nt.html
http://www.bodybuilding.com/store/bsn/xplode.html

I take these two
http://www.bodybuilding.com/store/cs/light.html
http://www.bodybuilding.com/store/eas/carbcontrol.html
Because I'm trying to drop weight. Less carbs more protein. If you're trying to gain more fat than muscle, then I would incorporate more carbs into your diet along with lean protein. With me I am incorporating vegetables, less carbs, and lean proteins.