i think that the use of AAS will also make a difference, if you are using then your body is more willing/wanting to absorb protein, every person will have a different level of absorption, then it will also vary depending on the type of protein you are eating, and possibly the time of day, i can digest much more at night than i can in the morning, eg 30-40 gm am but 50-100 eve, also depends on when you trained last, for me that is usually the eve, so this will affect my eve consumption ability. not sure if there are any tools to help you find out how much you can digest, i personally use feelings of fullness or bloatedness.
regarding enzymes and such, i thought that you only need pepsin to digest protein, and that you digest then absorb?
regarding enzymes and such, i thought that you only need pepsin to digest protein, and that you digest then absorb?