Definitely count the protein in the egg. The rest of it is dependent upon how much of the simmering mixture is actually absorbed.
To figure that out, you would measure out your ingredients prior to simmering, then measure out what you have left after simmering. Most of difference is what was absorbed. Not a perfect way to measure, though, because some of the liquid will be lost during the simmering phase as it evaporates; but should be able to get a ballpark idea on it.