I agree with Richard.

I have no doubt that the Paleolithic people ate the whole animal: muscle, fat
and organs, and may have prized the fattier portions of meat. BUT these
fattier portions of available Free Range or Grass Fed animals is no were as
near the fat content (and no were near the fat make up) of today's' grain fed
animals (As Richard so eloquently demonstrated).  So If you are trying to
mimic a Paleolithic diet it only makes sense to eat leaner, grass fed meat
since this closer resembles the type of meat humans ate during the major part
of our evolution.  In other words, we are plumbed and wired to live on a lean
meat diet.  It just makes sense.

I have been on Cordain's version of Paleo Diet for 2 months now, I've lost 21
lbs, 10 more to go. I have never cheated and have no desire to.  I eat grass
fed buffalo, rabbit, lots of free range chicken and turkey and fish. With
lots of veggies and fruit.

Perhaps marinating in flax seed oil is not a great suggestion, but his
reasoning for it is sound (to improve the omega 6-3 ratio) Unfortunately flax
seed oil is not so great to cook with, but it is great in salads!

Bottom line: Cave man never ate Prime rib with all the fat (from a grain fed
cow) smothered in butter, goose fat or coconut oil.

Keep smiling, Alex