40g of protein is the largest possible amount the body can process, I have no scientific literature to support this as my lab is my gym and the subjects are professional rugby players. Through trial and error we have found this to be the most effective amount. Although I am sure if you search you will find some sort of journal to back it up.
I am all for peer reviewed papers, however, most of the time the study has been conducted on untrained subjects or for too short a time. If i find something that works i use it and dont wait for it to appear in a journal.
Try it for yourself and see how your body responds, you may find you need more/less.