At the core...

At the big 5's core is the belief that saturated fat is good for you and should make up more of the human diet than it is allowed to do in modern day society. In addition to the paleo principle, here's a great article on the science of the failed hypothesis that saturated fat causes plaque build up in the arteries, higher incidence of heart attack and stroke, death, and other maladies.

Read it. Or skim it. At least understand that the science is not with those who claim that fat is bad for your cardiovascular system.

edit: And here's a short primer on cholesterol for those of you unaware of the "paradox" that higher cholesterol never tends to be an indicator of an increased rate of heart disease, no matter how the "researchers" try to manipulate the data and the studies from one of my favorite recent finds, Free the Animal.

To summarize, I'm operating under the assumptions (which science both predicts and finds when it measures) that you'll be healthier if you eat fewer grains/grasses and more animal fats. This stands at the Big 5's core.