What is a "Paleo" diet, anyway?

My interpretation of the "Paleo" diet is that it’s not about eating the exact same things that the Paleolithic people ate, or somehow returning to the primitive.  Rather, it’s about duplicating the human metabolic environment of the period.

Quite a bit is known about the diet and lifestyle of the period.  For example, have a look at Catching Fire: How Cooking Made Us Human, by Wrangham, or  Meat-Eating and Human Evolution, by Stanford and Bunn.

[[MORE]]While dairy wasn’t consumed in the Paleo period, it is certainly compatible with Paleolithic metabolism in the sense that it’s an animal product, high in fat and protein.  Two of the best tools you have to replace carbs are butter and milk fat.  They may not be “orthodox” Paleo, but they are definitely acceptable in terms of metabolic affects, provided you aren’t allergic.  Many dairy allergies seem to be provoked by gluten; once gluten is removed from the diet, those sensitivities often go away; sensitivities are also minimized by using dairy products with a high fat (and therefore low protein) content.

Here’s Dr Kurt Harris’ step-by-step approach to the paleo diet, which I think is fabulous (and is what I’m following).  See his blog at http://www.paleonu.com/.  He thinks that by the time you get to step #9 you have 80% of the benefits, and by adding proper exercise at step #10, you have 99%; eliminating dairy provides only a very small benefit after that.

1. Eliminate sugar (including fruit juices and sports drinks) and all flour
2. Start eating proper fats - animal fats and monounsaturated fats like olive oil - substituting fat calories for carb calories. Drink whole milk or half and half instead of skim.
3. Eliminate grains
4. Eliminate grain and seed derived oils (cooking oils) Cook with butter, coconut oil, olive oil or animal fats.
5. Get daily midday sun or take 4-6000 iu vit D daily
6. Intermittent fasting and infrequent meals (2 meals a day is best)
7. Fruit is just a snickers bar from a tree. Stick with berries and avoid watermelon which is pure fructose. Eat in moderation.
8. Eliminate legumes
9. Adjust your 6s and 3s. Grass fed beef or bison avoids excess O-6 fatty acids and are better than supplementing with 0-3 supplements.
10. Proper exercise - emphasizing cross-fit or interval training over long aerobic sessions
11. Eliminate milk (if you are sensitive to it, move this up the list)
12. Eliminate other dairy including cheese (now you are "orthodox paleolithic")

One natural consequence of this approach is that it tends to be relatively low carb. If you start with a SAD-like diet and eliminate sugar, grains, fruit and legumes, the resulting diet will have fewer carbs than when you started.