Well I was just reading a study comparing protein synthesis in postmenopausal women vs. men of the same age (the study group were aged 65-80), which found that the women converted a much smaller percentage of their protein intake into muscle. The authors compared their results to other studies of younger populations (pre-menopausal women, with men of comparable age), where there was no significant difference between the sexes.

So the conclusion they drew was that post-menopausal women need to eat more protein than pre-menopausal women, or men of any age.

It was a very small sample, but IIRC the results were pretty striking. Not surprising they couldn't recruit more test subjects, considering the study involved a cannula in each arm (one for protein infusion, one for blood draw) and three quadriceps biopsies

Just one study of a small sample, but "food" for thought