Kurt Harris and Mark Sisson both argue that you don't need to eat 100% Paleo all the time. It seems to me if your goal is weight-loss that's pretty uncontroversial, while if you went Paleo for a specific illness you would probably go 100%.
In my case I came to Paleo for my heart and cholesterol numbers, confident that SAD was taking me to a heart-attack. I guess a lot of people on Paleohacks may have come to Paleo for the same reason.
So I want to ask opinions on whether there is some magic degree of fidelity for avoiding diseases of civilization, or some particular food that is absolutely non-negotiable for long-term heart outcomes.
My own guess is the absolute no-no-list is refined sugar and glutens, but I'm pretty new to Paleo so I want to hear from others.
There definitely isn't a general, identifiable tipping point; like everything else in life, the change occurs at the margin.
If you're exercising regularly and eating a clean paleo-style diet for 90% of your meals, you'll never have to worry about the "diseases of civilization".
I also don't buy into the idea that any food is "non-negotiable". That implies that eating it even once a year will irrevocably damage your health. Our bodies are not that fragile. You could probably smoke crack laced with High Fructose Corn Syrup and pure wheat gluten once a year and not die a single day earlier.
For heart healthy paleo/low carb blogging, I follow Dr William Davis at
Non negotiable items on the no list: No oatmeal, no refined oils like soybean, safflower, canola, corn, margarine, anything hydrogenated, no store bought salad dressings. No sugar free anything, no soy anything.