You’ve heard it before: Based on the idea of eating like a caveman, the ever-so-popular Paleo diet forbids anything our Neanderthal ancestors couldn’t find, catch, or kill — including all processed foods, refined sugar, salt, and dairy. But what did Neanderthals actually eat? According to a new study from the University of Tübingen in Germany, the original Paleo dieters may have eaten each other, Mic reports. In an area known as the Troisième caverne of Goyet, located in modern-day Belgium, Neanderthal remains dating back to 40,500-45,500 calBP (an archeological term that means "calendar years before present") were discovered almost 150 years ago. Recently, after conducting a multidisciplinary analysis of the remains, researchers found marks on the bones that pointed towards evidence of cannibalism: “Our results show that the Neandertals from the Troisième caverne of Goyet were butchered, with the hypothesis of their exploitation as food sources the most parsimonious explanation for the observed bone surface modifications,” the study reads. These findings provide “the first unambiguous evidence of Neandertal cannibalism in Northern Europe.” So, there you go: yet another reason not to jump on the Paleo bandwagon. But okay, beyond this gag-inducing addition to our understanding of the Neanderthal diet, it's also worth knowing that there are other downsides to going Paleo. In fact, in a recent study in Nutrients, participants who adhered strictly to the Paleo diet lacked the important nutrients thiamine, riboflavin, and calcium. Anyway, vitamins aside, we really, really don't recommend adhering to this latest creepy development in the wacky web of the Paleo world.