Damn silverbackn, good lookin' out, it does have other minor functions. Insulin also controls the uptake of valine, leucine, and isoleucine by the muscles, which in turn helps to increase the synthesis of muscle proteins (Stryer 773). I'm not sure whether or not this increases the amount of protein you can absorb by any valuable %, but it does increase uptake of at least 3 AA's anyway. As far as I could tell though it doesn't shuttle anything but glucose, those 3 AA's it just helps other processes increase uptake, but still I stand a corrected penguin