By far the most exciting health trend to hit the scene in the last few years is the Carnivore Diet. Tens of thousands of people are adopting it. Passionate online communities devoted to discussing and extolling the virtues of exclusive meat-eating have sprung up. And while in raw numbers it isn’t as big as keto, “carnivore diet” is running neck and neck with “vegan diet” on Google Trends for the past year. It’s one I’ve been watching for a long time.
Over ten years ago, I addressed the idea of a zero-carb carnivorous diet right here on this blog.
A few years ago, I went over the advantages and shortcomings of the carnivore diet and even gave my suggestions for making it work better.
Earlier this year, I explored the notion of a seafood-based carnivorous diet.
Today, I’m going to pull it all together and give an overview—a definitive guide, if you will.
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Okay, so what is the Carnivore Diet?
It’s quite simple (which is part of the appeal and effectiveness). You eat meat and don’t eat plants.
If it explored three-dimensional space by hoof, claw, wing, or tail, had live kin or laid eggs, and defended itself with direct action, non-violent resistance, or by fleeing, you can eat it (and its products). If it rooted itself to the ground, reproduced by bee, consumed sunlight and water, and defended itself with chemical compounds, you cannot eat it (or its products).
If it sounds extreme, you’re right. The carnivore diet is unlike anything most people have ever considered.
But adoption rates aren’t exploding because everyone’s deluding themselves: People are reporting real benefits.
Clearer thinking: If a carnivore diet induces a state of ketosis, it will also increase mitochondrial biogenesis in the brain and reduce brain fog. This allows your brain to generate more energy and clears out excess ammonia which slows down the thinking process.
Improved gut health: A carnivore diet is an extreme elimination diet. It eliminates all the most common triggers of gut inflammation, including fiber, lectins, grains, legumes, sugar, seed oils, and in some cases dairy. If any of those foods are the cause of your gut inflammation, removing them from your diet will improve your gut health and even allow it to heal.
Weight loss: Weight loss gets a whole lot easier when you’re not starving. Most people who go carnivore find they’re unable to eat enough to gain body fat; the diet that is most satiating while still being nutritious will almost always come out ahead without even trying.
What Do You Eat On a Carnivore Diet?
At the heart of it, the carnivore diet is very simple: eat only animal foods and do not eat plant foods.
Meat: beef, lamb, bison, pork, chicken, turkey, venison
Seafood: fish, shellfish, shrimp, crab, lobster
Animal foods: eggs, bone broth, animal fat, bone marrow, organs
Eating food from all three categories on a consistent basis is important for obtaining all the nutrients you need.
The following foods are contentious and not all carnivores eat or accept them.
Dairy: milk, cheese, cream, butter; some carnivores avoid lactose and only eat low-lactose dairy like hard cheeses and butter and cream.
Honey: since honey comes from bees, which are animals, honey is technically a carnivore-friendly source of carbohydrates.
Most carnivores allow salt and pepper. Some use herbs and spices and even things like garlic. Some carnivore dieters avoid coffee, tea, and alcohol because they’re made from plants. Others permit them.
Carnivore vs. Keto
If carnivore sounds a lot like keto, you’re right. There are many similarities between carnivore and keto.
They’re both lower-carb and higher-fat than other diets.
They may both help you reach ketosis.
They both involve eating a lot of animal products.
The main difference is that keto contains plants and carnivore isn’t necessarily low-carb.
You could be keto and eat entire salad bowls full of leafy greens.
You could be carnivore and eat 100 grams worth of carbohydrates from milk.
You could be carnivore and eat more protein and more moderate amounts of fat, while keto is by definition a high-fat diet.
But, as commonly practiced, the two can be very similar. Most carnivore dieters eat close to zero carbs, a good amount of fat, and are in ketosis much of the time. Most keto dieters eat more animal products than the average person. It’s very easy to combine the two. In fact, there’s a clinic in Hungary called Paleomedicina that does exactly this, using a high-fat “paleolithic ketogenic” carnivore diet (2:1-3:1 fat:protein ratio) to treat patients with otherwise intractable chronic autoimmune diseases like type 1 diabetes, Crohn’s, and rheumatoid arthritis. Not only are they getting great clinical results, they’re getting great results and closely tracking relevant biomarkers.
Which leads me to the next section…
Who Should Try Carnivore?
Anyone can try it. Populations for whom carnivore seems to work best are people with autoimmune or immune ystem diseases like eczema or rheumatoid arthritis, and people with gut disorders like IBS or Crohn’s.
People with autoimmune and gut disorders almost always have dysfunctional and dysregulated gut biomes, and carnivore represents a hard “reset” for the gut. You pull out all the fermentable fibers and sugars and carbohydrates and gut-disrupting antinutrients found in plant foods and go back to square one.
Carnivore Diet Pros
Animal nutrients are more bioavailable.
Plant nutrients usually undergo a conversion process before humans can utilize them, and not every human has the same conversion capacity. Meanwhile, animals and their constituent parts contain nutrients in the perfect form for other animals to absorb. Retinol is the “animal form” of vitamin A, and it’s far more effective than beta-carotene, the plant form. Long-chained omega-3s found in seafood are far more effective than shorter-chained omega-3s found in plants, which must be converted to the longer “animal form.” Name a nutrient, and it’s probably more bioavailable in animal form.
Animal foods contain unique nutrients you can’t get in plants.
Some of those essential and/or helpful nutrients only occur in meat, like creatine, carnosine, taurine, or vitamin B12. If you don’t eat meat, there’s literally no realistic way to obtain these essential (or conditionally essential) nutrients without relying on supplementation, which didn’t exist until the last hundred years.
Animal foods have no toxins.
Because animals can run and bite and claw and fly to get away from predators, they don’t need to employ kind of passive chemical warfare that many plants use to dissuade predation. Plants cannot run. They cannot move, and so they must manufacture chemicals that irritate guts or outright poison the animals who seek to eat them. There are no phytates, lectins, gluten, oxalates, or other problematic compounds in a ribeye. Except for blatant allergies and intolerances to red meat, like the ones that arise with a Lone Star tick bite, meat is safe from a toxin standpoint.
Eating meat made us human.
When hominids ate very little meat, maybe grabbing a leg bone here, a lizard here or a mouse there, our brains were much smaller and less impressive. As hominids progressed and grew more intelligent, their diets changed to include more and more animal food. They started out as scavengers, cracking bones and skulls left behind by more obligate predators. They developed thrusting weapons. They became incredible throwers and developed lethal projectiles. They developed language and tactics to coordinate assaults and lay traps. And as the meat poured in, the brains grew. Humans as we are them today emerged stepwise with meat.
My take is that it was a combination of a few things:
- Animal meat, fat, and animal-based nutrients. The human expanded as we ate more and more meat, although the causality isn’t clear . It could be the nutrients, protein, and calories found in animal foods provided a stimulus for brain expansion. It could be that our desire for meat necessitated an expanding brain to enhance our intelligence, cunning, tool-making, and hunting ability—that those humans whose brains expanded were better adapted to hunting. It could be all of that at once (my guess).
- Fire. With fire, we could extract more calories from both plant and animal foods—cooked tubers are more digestible than raw and fire allowed us to access the residual calories bound up in bones and connective tissue. Paleo-anthropologists call this “grease processing”: boiling pulverized animal bones in animal skins to extract every last drop of fat, gelatin, and protein.
- Seafood. Early humans were coastal dwellers. Researcher Stephen Cunanne has been beating this drum for over a decade, showing through anthropological and neurological evidence that the long-chain omega-3 fatty acid DHA was necessary for human evolution and brain development.https://pubmed.ncbi.nlm.nih.gov/25373088/“>1
The point is undeniable, though: the expansion in human brain size and intelligence clearly coincided with the rise in meat consumption.
Now, none of these arguments confirm that we should only eat meat and eschew all plant foods. They do confirm that meat is a natural part of the human diet—and a major part.
Carnivore Diet Cons
Detractors point out some potential cons to the carnivore diet. How do they hold up?
Detractors say carnivore is unhealthy because it precludes fiber. Is this true?
For one, it’s not quite true that carnivore diets contain no fiber at all. Animal fiber exists in the form of gristle, cartilage, and connective tissue, and at least in other obligate carnivores like cheetahs, can provide prebiotic substrate that enriches the gut bacteria.https://www.ncbi.nlm.nih.gov/pubmed/22074361“>2
Two, it’s unclear whether fiber is necessary. Clearly, it’s not essential in the sense that you will die without it. And there’s evidence that “more fiber” is necessarily helpful in digestive disorders, and may even be harmful. But there is good evidence that prebiotic fiber offers beneficial metabolic and gut health effects in the average person eating an average omnivorous diet. And no, it’s not just about fecal hypertrophy. There is real evidence that feeding your gut bacteria soluble and prebiotic fiber can enhance health and produce beneficial metabolites.
Where the question remains is whether those benefits occur in carnivorous dieters, or whether carnivorous dieters need fiber. Is fiber necessary only on omnivorous diets? Perhaps. I suspect we’ll learn more as time goes on.
While meat is a great way to get bioavailable sources of most B vitamins and many other unique nutrients, plants are the primary sources of folate, magnesium, potassium, and vitamin C in the diet.
If you’re not careful, a low-carb diet can lead to low levels of folate.https://onlinelibrary.wiley.com/doi/pdf/10.1002/bdr2.1198“>3 Dr. Ted Naiman has seen this in carnivore patients of his who are otherwise healthy and robust. The best sources of folate on a carnivore diet are liver (which you can’t eat every day because of excess vitamin A) and egg yolks (which must be pasture-raised or follow a specially-formulated diet to be really rich in folate). Eggland’s Best Organic eggs are actually a decent source of folate and readily available if you can’t get pasture-raised.
There are no great animal sources of magnesium, with the best probably being halibut and cod. Snails and fish eggs are also good sources.
Meat is a good source of potassium but you have to make sure to consume all the juice. That means eating your meat rare and letting it rest before cutting into it.
Chris Masterjohn had a great talk with Paul Saladino about the vitamin C/carnivore issue. Chris’ stance was that while a well-made carnivore diet can provide enough vitamin C to avoid scurvy, it might not provide enough vitamin C to be optimal and do the “extra stuff” vitamin C can do. Paul was more skeptical of the need for higher levels of vitamin C. Where both agreed is that a carnivore must eat organ meats (liver and kidney, especially) to obtain enough vitamin C.
If you don’t eat dairy or bone-in small fatty fish, you risk calcium deficiencies—so consider incorporating them.
The potential exists for micronutrient deficiencies. Eating a bunch of turkey breast or ground beef won’t cut it.
In previous posts, I’ve supported the idea that plants are important to eat, or at least incorporate as medicinal inputs—in marinades, in teas, in small amounts.
I stand by that assessment. I still like vegetables. They don’t affect me in a negative way and they taste good. They’re low-carb, provide helpful micronutrients, and reduce the formation of harmful fatty acid peroxides in the digestion process.https://pubs.acs.org/doi/abs/10.1021/jf040401o“>4 Used in marinades and sauces, plants and herbs can reduce the formation of carcinogens during the cooking process. And every traditional culture we’ve ever seen—even the Inuit and Masaai—consumed plant foods on a regular basis and considered them important and even essential.
If you are someone who reacts poorly to the plant compounds found in vegetables, you may be better off not eating any. Vegetables aren’t required for survival like meat and animal fat are required. But if you can tolerate vegetables, it’s a good idea to eat them. To me, the benefits are great enough that I recommend most people (even carnivores) sample vegetables until they find some they can tolerate. Remember: there’s a difference between eating vegetables for calories and eating vegetables for medicinal purposes.
There are also acute issues that sometimes arise with carnivore diets.
What happens if you’re not pooping like you should?
Confirm you’re actually constipated. Carnivore is a low-residue diet. There’s not much left over after you absorb everything. You’re not eating loads of fiber and most of the nutrients you’re taking in are highly bioavailable. No matter what happens, you won’t be practicing fecal hypertrophy like you were on an omnivorous diet containing fiber. Your “lack” of pooping may be totally normal.
Get more electrolytes. Salt, magnesium, and potassium all impact your digestion. Potassium and magnesium in particular are required for optimal muscle contractions, including the muscle contractions that move food along the digestive tract. Salt provides the chloride we need to produce hydrochloric acid, aka stomach acid.
Check your fat intake. A mistake some people make when starting a carnivore diet is eating too much lean meat. Adding in fattier cuts of meat can speed things up.
Give it time. Your gut biome is adjusting to the new environment. Things may take awhile to normalize. Resistant starch can help here.
Back when Joe Rogan went carnivore for a spell, he had incredible energy and body composition shifts but first had to get past the “explosive diarrhea.” Reports from others around the Internet suggest that this isn’t rare for people just starting out. What to do?
Too much fat, too fast. Increase fat intake more gradually.
Rapid shifts in the gut biome. Suddenly removing all the substrate your gut bacteria were eating can throw things off. Give it some time.
Resistant starch if it persists. If the diarrhea lasts longer than a couple days, try a little raw potato starch (for resistant starch) to improve consistency.
If you noticed, the reasons for diarrhea track closely with the reasons for constipation. Changes to the gut biome can manifest differently along the same diarrhea/constipation spectrum and often have the same solution.
Carnivore Diet Supplements
If you do it perfectly, a carnivore diet should contain all or most of the nutrients you need to thrive. But supplements can make it easier, and they may optimize your experience. A few to consider:
- Mineral water
- Freeze-dried organs
- Fish oil
- Broad-spectrum polyphenol blend
Magnesium: Important electrolyte, vital participant in over 300 physiological functions, and rather hard to get on a pure carnivorous diet. Almost everyone should be supplementing with magnesium.
Mineral water: A good mineral-dense sparkling water like Gerolsteiner is a nice way to obtain hard-to-get minerals like magnesium and calcium.
Freeze-dried organs: The ideal is to eat liver, heart, kidney, and/or spleen on a regular basis. They’re more nutrient-dense and contain wide ranges of nutrients you won’t find elsewhere in the animal. If you can’t or won’t eat fresh organs, you can get freeze-dried capsules.
Fish oil: If you’re not eating seafood, you need a source of long-chain omega-3 fatty acids. Fish oil is the most straightforward way to get them.
Collagen: Collagen is necessary to balance out your intake of muscle meat—which will be elevated on a carnivore diet. In the absence of a steady intake of gelatinous bone broth or direct consumption of connective tissue, collagen peptides become essential.
Broad-spectrum polyphenol blend: The carnivore people go back and forth on polyphenols. Are they plant poisons? Plant pesticides? The point remains that the evidence in favor of polyphenol intake is quite robust. And yes, polyphenols are stressors. They act as plant toxins that our bodies interpret as hormetic stressors and trigger a beneficial response. I wouldn’t take something like this every day (nor do I), but I would take it intermittently as a stand-in for intermittent plant consumption.
Electrolytes: Electrolytes are essential, especially on any carb-restricted diet (keto, low-carb, carnivore, etc). There’s this dedicated electrolyte supplement that Robb Wolf helped design, or there’s my own Collagen Quench mix that also contains collagen, vitamin C, and polyphenols (from fruit powder) in addition to the potassium and sodium.
So, Does Carnivore Work?
Carnivore appears to work.
A big part of staying healthy in the modern environment is the erection of artificial boundaries and the self-administration of artificial hardships. We could eat 10000 calories of junk food a day if we wanted. We could sit on the couch and be entertained and have all our food delivered to us if we wanted. Most of us never have to do an iota of actual physical labor if we don’t want to. But because doing that would make us sick and fat, we limit ourselves to moderate amounts of healthy real food, we go the gym, and we make it a point to take walks. These are artificial interventions we enact to emulate the ancestral environment to which we are adapted. These are boundaries.
There isn’t a simpler boundary to set than “eat animals, don’t eat plants.” And therein lies the power.
Now, I’m not going carnivore anytime soon. Although I have shifted my eating in that direction, I’ll always die on the “Big Ass Salads are great” hill (even if I’m loading them up with extra meat and cheese). Carnivore is exciting because it reveals that there’s room for extremes:
It shows that eating only meat won’t kill you—and it may make you stronger. It won’t give you diabetes, colon cancer, heart disease, or make you obese. A diet based on animal foods is safe and, for many people, optimal.
Gut health is paramount. Health starts in the gut, as Hippocrates said, and extends to every manifestation of your wellness. Carnivore might not be the only way to fix a leaky, dysfunctional gut, but the fact that it’s so good at improving gut health-related conditions should give you pause.
Plant foods are not benign. The popular conception of a “healthy diet” is one awash in leafy greens, broccoli, whole grains, and other plant foods. Mountains of produce, a “baby’s fist-sized piece of lean meat.” Even those of us who’ve been weird enough to eat low-carb diets rich in animal fat for years often have a tough time washing that stereotype from our consciousness.
Carnivore repudiates what all the health authorities tell us to do. It’s the exact opposite of what our moral and scientific “betters” have been preaching for decades. And because I’ve always been an iconoclast, someone who bristles at the thought of being told what to do, this appeals to me. I’ve never been convinced by the shoddy evidence that meat is bad for us. That entire legions of people are eating nothing but meat and failing to come down with the colon cancer and heart disease they’re “supposed to” is endlessly satisfying.
Once more, I don’t think carnivore is necessarily sustainable for a lifetime, especially if you don’t take special care to eat nose-to-tail-to-tendon-to-tripe-to-skin. But I do think it’s worth a hard look for people with autoimmune diseases, gut disorders, or those people for whom no other diet has worked. I think carnivore-adjacent eating will become a thing. I think carnivore cycling paired with cycles of omnivory will prove useful for a great many people.
What about you, everyone? Have you tried the carnivore diet? Would you?
About the Author
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.