Prior to reading Loren Cordain's book, I had understood the upper
limit on protein to avoid protein toxicity to be an absolute one
(as opposed to a percentage one) of about 200g per day. The book
says that for most people it is in the range 200 to 300g per day.

If that is the case, then the typical Paleo Diet data given on page
26 of his book, at 190g per day seems to taking things close to the
limit (for some people). Is it a good idea to take any part of the
body (e.g. the liver) close to its limits of coping?

I am unsure whether the upper limit to avoid protein toxicity is
absolute, percentage, or of some other type. If it is a limit on
percentage of calories obtained from protein (as opposed to a fixed
number of grams of protein per day), then someone who takes in
sufficient calories to support a large muscular body and a
strenuous life can eat a larger number of grams of protein per day
than a slender sedentary person who takes in fewer calories.

Could anyone shed any light on this please?

P.Smith