Ancestral health means living like people lived for hundreds of thousands of years before life got messed up - before food ingredients with names you cannot pronounce and high fructose corn syrup in everything, before fear of eating healthy fats and red meat, fear of being out in the sun, before we started exercising like rats on a wheel, before everyone was taking medicines that do more harm than good.
The ancestral health movement includes: Paleo, the Primal Blueprint, the Weston A. Price movement and other similar approaches. My primary orientation is Mark Sisson's Primal Blueprint, which is based on the Paleo Diet but is IMHO more sensible and easy to follow.
Authority Nutrition by Kris Gunnars is the most accessible explanation I've found. The site is somewhat slick but there is lots of documentation.
The premise of Paleo is that our ancestors evolved over millions of years to eat a certain diet. Agriculture has existed around 10,000 years, and much less than that in most of the world. That is not nearly long enough for us to have evolved to eat grains or highly processed foods such as seed oils. Most followers of Paleo no longer have a rigid "if cavemen didn't eat it neither should we" attitude. "Primitive" isn't always best.
Strict Paleo ("Caveman") Diet
We should eat like cavemen and women.
- Eat lots of lean red meat. (Paleolithic people did not do that.)
- Also eat eggs, fish and some poultry.
- Eat vegetables and fruit.
- Avoid all grains, legumes (beans, peanuts, etc.), seed oils, dairy.
- Avoid new world foods, especially the nightshades (potatoes, tomatoes, peppers and eggplant) because our Paleolithic ancestors did not eat them.
- Eat low carb meals.
Primal Blueprint and Similar Approaches.
We should learn how Paleolithic hunters and gatherers lived and ate. We should think about whether those apply to living in the 21st century.
- Eat moderate amounts of red meat, fish, poultry and eggs. Eat the whole animal, e.g. liver, rather than just red meat.
- Butter, hard cheese, cream, sour cream, yogurt and other dairy products are fine if you tolerate them well. Generally avoid milk. If you do drink milk, drink whole milk. Many Paleo/Primal people use raw milk. I do not. It probably is safe but I'm not comfortable with it. I use minimally pasteurized, non-homogenized dairy when I can. I do eat well-aged raw milk cheese.
- Saturated fat, especially from grass-fed and pastured animals, is good for you.
- New world foods such as tomatoes, peppers, avocados, potatoes, maple syrup and various other fruits, vegetables and nuts are OK.
- Most of what you read about fruit in Paleo books, web pages and blogs is very wrong. Fruit is fine to the extent you can handle the carbs/sugar. Read this post by Denise Minger.
- Potatoes are fine if you can handle the carbs. Paleolithic hunters and gatherers ate lots of roots and tubers. Most are not available now.
- Beans that have been soaked overnight and rinsed are OK if they don't cause problems for you. They are Paleolithic.
- Avoid most grains. White rice and some other grains are OK in moderation if you can handle the carbs.
- If you need to lose weight (fat) or heal from metabolic syndrome, you need to keep your carbs low. If you don't, eat however many carbs you need, especially if you do heavy work, workouts or other activities. Primal emphasizes fairly low carb but not zero carb.
- You need to do lots of things besides just eating right, e.g. get proper exercise and rest.