that doesn't really explain to him why it'll make him fat, lol. i dunno how accurate this is but let me take a stab at it. insulin carries triglycerides, aminos, and glucose to cells in the body wherever they are needed. you take in a certain ammount of slin and it does its job with what it has to work with, once it has shuttled aminos and glucose to all areas or most areas that need it its going to start doing the same with triglycerides wherever they are needed. hence, you get fat.
dj