At least that’s the argument that an international team of researchers (read: real scientists, not self-proclaimed Paleo wellness experts with blogs) have made in The Quarterly Review of Biology. After poring over the anthropological, physiological, and genetic data, they concluded that there’s a big discrepancy between the original Paleo diet and our modern take on it. More specifically, our ancestors ate a lot of carbs. MORE: 7 Ways To Go Paleo on a Budget Turns out, early humans needed a lot of glucose to meet the metabolic demands of their growing brains, as well as help moms-to-be supply steady energy to their growing fetuses. They might have been able to get a little bit of glucose from meat, since animal proteins deliver a small amount of glycogen, a sugar that the body can break down into glucose. Fruit might have been a source of glucose, too, but finding it was probably a rare treat. (Plus, you’d have to eat a ton of wild blueberries to match the number of carbs you’d get in something like a potato.) More than likely, our cave-dwelling ancestors probably hit the glucose motherload by chowing down on starchy carbohydrates like roots and tubers. Of course, the study authors didn’t just come to this conclusion by process of elimination. To unlock the maximum amount of energy from starchy carbs, you’ve gotta cook them. And evidence suggests that right around the time we started using fire to cook our food, evolution began to favor the development of the salivary amylase gene, which helps the body break down starch. Isn’t nature smart? MORE: The Real Paleo Diet Was Actually Super Gross What’s more, there’s a limit to how much meaty goodness humans can actually eat (SEE: 5 Dangerous Things that Happen When You Eat Way Too Much Protein). According to experts, protein can’t make up much more than 40% of your total calories. Go above that, and you could end up damaging your kidneys. Finding enough protein to make up more than 40% of your diet would probably be difficult anyway. Your body needs energy from carbs to run at high speeds for long distances, like when you’re chasing an animal to kill for dinner. Which means that if our Paleo ancestors weren’t eating any carbs in the first place, they probably would have had a hard time catching any antelope or buffalo, period. Does this give you license to eat mashed potatoes morning, noon, and night and still say you’re following a Paleo diet? Don’t even answer that. But if you want to swap half of your ginormous chicken breast for some roasted butternut squash, you probably shouldn’t feel guilty. In fact, you might even notice you have a little more energy for your nighttime run—even if the only wild animal you’re chasing is a squirrel.
