I recall Christopher Sommer claiming on the Tim Ferriss podcast that, as he gets older, he prefers to eat protein less often. I think like two large portions per week, IIRC.
Then again M. Berkhan of leangains fame recommends a high protein diet because it fills you up without being converted to fat and actually resulting in less net calories, thus leading to less body fat (or so).
Something I wonder, however, is how oldtimers used to get ripped, when animal protein was more of a luxury item and the general population relied more on grains, potatoes, veggies, and animal fat. Does anyone have good information on that topic?