Derek Nance has a bone to pick. Constantly.

For the last five years Nance has eaten only raw meat from animals he slaughtered.

He consumes almost the entire carcass -- the innards and fat included. The nearly exclusive flesh diet makes us queasy, but Nance believes it cured his own nausea condition.

Five years ago, Nance was vomiting constantly. He began to experiment with several diets, including vegan. Then he went to the other extreme, excluding almost anything without a heartbeat, as part of his own interpretation of the Paleo diet (also known as the caveman diet).

"I've physically gotten stronger and more physically robust," he told The Huffington Post.

And no expiration dates for this committed carnivore. Rotting meat is OK. Someone else's rancid is Derek's USDA choice because it's probiotic, he told Vice.com in a story that sparked viral interest in the 30-year-old Kentuckian.

Dad doesn't approve, but his vegetarian girlfriend understands. A father of four, he also admitted to HuffPost that his eating habits "kind of led up to" his previous marriage ending in divorce. It's complicated.

Nance's unusual meal plan (lamb is his preference) has been documented from time to time over the past few years. A 2012 YouTube entry shows him cracking open a lamb leg that's been aging in the fridge and sucking out the marrow. "I wash it all down with a good cup of blood," he says, and does so.

But perhaps our favorite raw video comes at the beginning of "Extreme Animal Obsessions," a short film posted on Vimeo in 2011. Spotting rabbit roadkill, Nance slices a piece and eats it right off the knife.

At least one dietitian has a beef with Nance's lifestyle, even if he occasionally indulges in an avocado or coconut. "Although in theory this may seem like a sensible diet, particularly when removing sugar and salt, it has eliminated several food groups like dairy and grains, which provide essential nutrients such as calcium, vitamin D, magnesium and phosphorus in dairy and B vitamins, fiber and antioxidants in grains," Joy Dubost of the Academy of Nutrition and Dietetics told HuffPost in a previous report on the Paleo diet.