When our Paleo ancestors settled down and began raising crops such as wheat and rice, that’s where our troubles began, according to Paleo advocates. They say grains are full of hard-to-digest gluten and “antinutrients” such as lectin, which prevent the absorption of other essential vitamins and minerals—while wreaking havoc on our digestive systems. “Our ancestors would soak or sprout their grains to get rid of these antinutrients, but we don’t do that,” says Neely Quinn, integrative nutrition therapist at PaleoPlan.com.
On the Paleo diet, even gluten-free grains like quinoa are verboten; you’re better off replacing them with more meat and vegetables. Still, many Paleo practitioners say it’s fine to “cheat” once in a while—a slice of birthday cake, say, or a plate of pasta or brown rice if you’re really craving it—so long as your body can handle the grains without any nasty GI side effects.