Quote[/b] ]But too much protein can actually inhibit gains. I know, it sounds totally contradictory to what you read everywhere, but it is true. Let me explain.
The ability of the body to grow is effected by the ratio of protein to carbs. It is an inverted U shaped curve where the top or highest point of the curve is a ratio of 12-15% protein to carbs (diet consisting of ~15% protein). At one peak you have all carbs, at the other you have all protein. It has to do with thermogenesis and hormones.
So, if a skinny guy wants to gain weight, he needs to plan a diet where he gets 15% of his calories from protein.
Now this may seem contradictory to the general rule of 1 gram per pound bodyweight. I'm not saying that a guy can't gain weight with more than 15% calories from protein. I'm only saying that weight gain is greatest at 15%. He will be ok with an intake of 0.75 grams/pound FFM to gain muscle. In fact, everybody should use FFM instead of bodyweight to plan protein intake. Sometimes its just to hard to figure it out, so most people use bodyweight.
For a guy who isn't all that skinny, or even a little fat, he should increase his protien intake to 20-25%. This will increase thermogenesis and prevent some fat gain as calories increase above maintenance.