Call it whatever you want: Paleo. The caveman diet. Primal eating.

Everyone from athletic trainers to holistic health professionals to diet book authors has something to say about why we should (or shouldn’t) take a lesson from ancient hunter-gatherers and get back to our dietary roots—which, Paleo enthusiasts will tell you, is the way humans were really designed to eat.

And for every nutritionist or worst-diets list that slams the plan, there’s a research scientist, endurance athlete or weight loss winner who swears by it.

What’s behind the hype?

The Paleo craze has its roots in a 1985 study by S. Boyd Eaton, M.D., titled “Paleolithic Nutrition,” published in the New England Journal of Medicine, and was further popularized by evolutionary medicine expert Loren Cordain, Ph.D., whose book The Paleo Diet, first published in 2002, is considered the seminal guide on the subject. Since then, guides to eating Paleo have proliferated, and while they may differ slightly from one another, they’re all based around a few common principles.

To give you a bit of an introduction to this prehistorically-minded nutrition plan, we broke the diet down into seven preliminary rules. Read on to learn the basics—and see if eating like a caveman could be right for you.