The Carnivore Diet: A Dietitian’s Perspective

by Nate Widom

This article has been reviewed by Jeannie Versagli, RD, LDN. Jeannie is a Registered Dietitian with the Academy of Nutrition and Dietetics, a national professional organization, and is licensed in nutrition with the State of Delaware.

A new fad diet has arrived! It’s the Carnivore Diet, and it entails only eating meat and animal products. But one thing is clear: any diet that skews dangerously close to being zero carb will have its setbacks. After all, carbs are essential! I sat down with Registered Dietitian Jeannie Versagli to discuss this new fad and what may happen to your body if your diet involves too few carbohydrates while being too reliant on protein and fat.

What is the Carnivore Diet?

“It’s interesting how this all started,” Jeannie says. Shawn Baker, MD and former orthopedic surgeon, began preaching the power of proper diet to his patients in the 2010s. Baker claims that, in many cases, dietary changes allowed his patients to come off their medication or even avoid orthopedic surgery altogether. It is worth mentioning that Baker’s license was suspended by the New Mexico Medical Board in 2017 due to competency concerns. Two years later, his license was reinstated, and he released his book, The Carnivore Diet, which became popular after gaining the attention of podcast host and comedian, Joe Rogan.¹

So, what is the Carnivore Diet? It’s a diet that includes only meat, seafood, eggs, and limited amounts of full-fat dairy products like butter, tallow, and heavy cream.² Carbohydrates of any kind are entirely absent from the diet – no veggies, fruits, whole grains, nuts, breads, or sweets.

These guidelines result in a meal plan with zilch carbs and lots of protein and fat. There are a few benefits that advocates of the diet commonly cite. One benefit is weight loss. Protein and fat are more filling, which can leave you feeling less hungry on the diet. “Fat is the last thing to be digested in the system,” Jeannie explains. “It slows digestion down, so you’re going to feel full longer.” The longer you feel full, the less food you are likely to eat, and the less you eat, the more likely you are to lose weight.

Another benefit you’ll often hear discussed is alertness. Protein tends to give off a caffeine-like effect.

Rogan himself claimed to have lost weight and gained energy after trying the diet for 30 days. Others who have adopted the diet have claimed to experience improvements in various chronic ailments including, eczema, rheumatoid arthritis, and even type 2 diabetes. However, research-based evidence about the safety and effectiveness of the Carnivore Diet is lacking. “There’s absolutely no scientific evidence that this is a healthy diet,” Jeannie explains. “There’s no research.”

A 2021 survey found “few adverse health effects,” and participants did report satisfaction and health benefits.⁴ However, those surveyed were pulled from online carnivore diet communities. Most were also long-time dieters, not those who tried the diet and stopped if it didn’t work for them.⁵ The researchers themselves even concluded that further study of the diet is needed.

Here’s what your daily intake might look like on the Carnivore Diet³

Breakfast: eggs, bacon, sardines
Lunch: turkey burger patty, salmon jerky, beef tips
Dinner: filet mignon, crab, chicken liver
Snacks: a small amount of parmesan cheese. jerky

Comparison to Keto

Jeannie likens the Carnivore Diet to the Keto Diet, albeit more extreme. The Keto diet is about using fat instead of carbohydrates to fuel your body in a process known as ketosis. While ketosis can result in more efficient fat loss, it requires decreased carbohydrate intake.

Carbs break down into glucose, the body’s most efficient energy source. Jeannie explains that when you limit the amount of carbohydrates you consume, “the body has to do a reset and start breaking down body fat or the fats you’re eating to generate fuel.”

Though conceptually similar, there is a clear difference between Keto and the Carnivore Diet. “With a keto diet, at least you have carbs,” Jeannie explains, “A keto diet can range anywhere from 45% carbohydrates down to 10%. [The Carnivore] diet eliminates EVERYTHING. You can only have meat. Nothing else. That’s it.”

Jeannie feels that Keto isn’t necessarily bad. She’ll even plan modified Keto diets for her nutrition clients when appropriate. That said, Jeannie would never endorse totally eliminating carbs. She always stresses the value of lean proteins and fiber, and she feels that a modified Keto plan can still provide a healthy ratio of carbohydrates, meats, and fats that is unachievable with the Carnivore Diet. “I’m very comfortable with 40% carbs for a general purpose because that means you can still get your vegetables in, nuts and fruits in, and a couple of complex carbohydrates like your grains,” she says.

You Need Carbs!

No matter the name, any diet heavy on protein and fat and lacking carbs may lead to deficiencies. We all need them! Below are just some of the main vitamins that carbohydrates provide that are limited or absent in animal products:^6,7

Jeannie doesn’t recommend the carnivore diet for anyone. However, adverse effects may be more prevalent in those who have chronic kidney disease, eating disorders, and cholesterol sensitivity as well as children and pregnant women.³

Vitamin C is not found in animal products; we generally get it from fruits and vegetables. It’s essential for skin and gum health and helps us absorb iron. Plus, it improves your immune system and lowers the risk of some cancers. If you are deficient in vitamin C for long periods, you can develop scurvy.
Magnesium is found in nuts, seeds, whole grains, and green vegetables. It regulates blood pressure and blood clotting and builds bones and teeth
Vitamin E is found mainly in plant-based oils, leafy green vegetables, and nuts. It protects your cells from damage and may prevent Alzheimer’s.
Folic acid or folate is found mainly in veggies and legumes. It’s vital for pregnant women as it helps prevent specific birth defects.
Fiber is found mainly in fruits, veggies, legumes, and whole grains. It can help with weight management and gut health and reduce the risk of type 2 diabetes and heart disease. It’s also known to alleviate constipation.

If that isn’t enough, both the Keto and Carnivore diets can also produce unwanted side effects. Ketosis is linked to bad breath, headaches, flu-like symptoms, lack of energy and fatigue, and insomnia.⁸Furthermore, the specific ratio of fats and proteins consumed can also result in constipation – when stool builds up in the bowel – or steatorrhea – when stool becomes oily and loose.

“All of our muscles would prefer to work off of glucose, and when you don’t provide it, the body may feel a little bit fatigued,” Jeannie explains. “You’re fighting Mother Nature when you’re doing that.” This effect will be especially prevalent in athletes and those doing high-intensity cardio.

Not All Protein is Equal

The Carnivore Diet also doesn’t stipulate the kinds of proteins to consume. Many meats, namely highly processed meats like sausage and bacon, are high in saturated fat, which is particularly problematic. This fat increases your LDL (bad) cholesterol, putting you at risk for heart disease and stroke. Not only that, but too much saturated fat can clog your arteries.

Since the adverse effects of saturated fats come later in life, Jeannie is concerned that people may find these diets appealing and not realize future downsides. “You could be compromising your cardiovascular health by eating something like this thinking you’re losing weight. But that fat will stay there,” she explains. “You do not have any fiber to pull it out, so you’re accelerating clogged arteries. Once you put that saturated fat in there, that plaque doesn’t go away.” Processed and cured meats are also typically high in sodium, raising blood pressure.

Jeannie recommends avoiding processed and cured meats if you enjoy protein. Consider lean chicken, turkey, fish, and less fatty cuts of beef.

Sustainability and Takeaways

Fad diets tend to catch on because enough people experience anecdotal benefits. However, it’s important to consider whether those positive outcomes result from the foods included in the diet or the foods cut out. Following the Carnivore Diet doesn’t just mean eating lots of meat and dairy – it also requires eliminating alcohol, potato chips, and other foods your body may not agree with. Baker himself admits, “If you get rid of the garbage, you’re going to have a benefit no matter what diet you go on.”

And then, with any diet, Jeannie always asks the critical question—whether they can sustain it. If your goal is to lose weight or overcome chronic fatigue, there are much less restrictive methods out there with extensive data to back them up. Due to insufficient research and nutrient considerations, Jeannie does not advocate for any diet that drastically restricts or limits carbohydrates. She recommends that all diets aim for a balance of wholesome, unprocessed foods rich in vitamins and fiber.