Here is my understanding of the basic ground rules for eating this way:
Eat lots of vegetables, organic if you can find them and afford them.
Eat fruits when in season, and when natural to your climate.
Eat lots of pastured, grass fed animals, including their fat if 100% grass fed and grass finished. Embrace organ meats and bone broth.
Eat wild caught fish and seafood.
Avoid packaged, processed, refined foods. That means junk food too, and anything white. Additives and chemical preservatives are to be avoided.
Avoid grains, legumes, and anything that takes a lot of processing to be edible. The wheat kernel or oat is not edible from the field. It would break a tooth! It takes a great deal of work to make it into bread, cereal, etc. The same goes for beans.
Eat dairy if it is 100% grass fed, and raw, unpasteurized. Keep in mind that it is still processed to become cheeses, ghee, and butter, so these are part of the gray areas in the rules.
Embrace good fats. I have written a post just about fats a few months ago, so scroll back to learn more.
Avoid sugar and artificial sweeteners. If one wants a treat, use natural alternatives like luo han gao, stevia, or xylitol. Better yet, grind up dates or figs, if appropriate for the dish. Honey is a healthier alternative, but it is still a sugar in the bloodstream, so do not go crazy.
These are the ground rules. Now, within these ground rules, one may find that they are sensitive to certain foods, like eggs or dairy. Tweak the lifestyle to meet one's individual health goals, medical needs, and preferences as well.
As always, use the 80/20 or 90/10 rule of thumb. Treats and sweets, wine, whiskey, etc. can be added if one enjoys them as part of the 20% party animal that lives inside all of us. Eat clean most of the time and one will see marked improvements in the physical and mental health. It isn't that difficult and it isn't that expensive, really.
Sleep well, play hard, and move often!