We're speaking to more and more of our customers who are following various versions of a carnivore way of eating so we thought we should dig into what it is and why people are following this diet.
Some have said they're following it for health reasons, others to lose weight and we've been told by others they are using it as a simple detox or reset.
We will firstly look at they types and variations of the carnivore diet then consider the pros and cons of each
What is the carnivore diet?
Essentially the carnivore diet is eating just meat but there are variations on this which people follow according to their needs and tastes with varying degrees of strictness and elimination.
The Animal Based Diet
Describing a diet as 'animal based' is the least restrictive version of carnivore as it allows the consumption of all animal based foods which include all meats, fish, eggs and dairy but with the inclusion of plant based foods with very low toxicity (more about this later). Plant foods considered to be low toxic are generally fruits and not grains, pulses or leaves however this diet, like all others, is subject to being whatever works for the individual, it is not nor should be completely prescriptive.
This diet however does vary from a Paleo diet in that most of the calories should come from animal based foods not plants and the plants are eaten as supplement rather than the other way around, plant based fibre is kept to a minimum.
All meats, seafoods, eggs and dairy (dairy if well tolerated)
All fruits and berries to include avocado (which is a fruit)
Not allowed foods:
Grains of any sort - no breads, cereals, pasta or pastry.
No seed oils (vegetable oils from seeds, olive oil, coconut and avocado is ok)
No legumes - Beans and pulses
No nightshades plants - Tomatoes, chilli, peppers, potatoes or aubergine.
Maybe (according to personal reactions)
Fermented vegetables such as kimchi, sauerkraut or pickled veg.
Some root vegetables that are not potatoes such as parsnip, sweet potato or carrot.
Conventional Carnivore diet
For most people's understanding this is the carnivore diet and it is simply consuming only foods of animal origin, that is all meats from grazing animals, poultry, pork and game as well as organ meats from those animals and any other foods of animal origin such as eggs from poultry or fish and any dairy products be it from cow, sheep or goat to include butters and cheeses.
Only water is drunk and only salt as a seasoning.
Cooking oils are strictly of animal origin and include tallow, lard, Schmaltz (poultry fat) as well as dairy cooking fats such as butter and ghee.
Variations / maybe foods:
As a seasoning salt is of course included but this is where the personal preference comes in, some people following this diet will use some flavouring herbs, pepper and even spices as well as tea or coffee to drink if well tolerated.
The Lion Diet
The lion diet is the strictest version of carnivore making it the easiest to explain as it contains just three ingredients.
Meat and organs from grazing ruminants (beef, lamb or goat) only.
For this version simply nothing else is permitted and this means that this diet is usually reserved for those who have serious medical conditions that the other versions have not addressed.
Above we've looked at the types or variations of the carnivore diet not not yet considered the why, why would or should someone try this diet?
The most common reasons for trying a carnivore diet are to help autoimmune issues and for weight loss although it is being increasingly adopted simply as a high performance diet for athletes, in this section we will consider why this is the case, after all, aren't plants good for us?
How organisms avoid being eaten.
In evolution there are no mistakes, every organism has found its place through millions of years of natural selection and in the case of many of our foods, thousands of years of un-natural selection as we cross breed to enhance certain traits that are beneficial to us.
Picture shows the original banana (top) and the modern version (below) created by cross breeding for desirable traits.
No animal 'wants' to be eaten and only those at the top level of an ecosystem do not have to fear predation, everything else has some method of defence which very often is simply the ability to run to avoid capture.
As much as the individual gazelle doesn't want to be eaten by the lion, a full grown male lion will eat 7gs of fresh meat per day and it needs prey to survive. Since nature is a balanced system using feedback loops the gazelle also needs the lion. Without being preyed upon, the population of grazing animals in any given system will rise to a point where it becomes unsustainable and will suffer from being undernourished. The lion and the gazelle need each other for balance.
However, as an individual, the gazelle can escape being eaten by running, the top running speed of a gazelle is comparable to a lion but it is more nimble and can keep running for longer giving it a real chance for escape, once caught however, it is doomed as it doesn't have defences to win the fight against the claws and teeth of a predator, once caught the gazelle is the perfect food for the lion.
You might be wondering where this is going so now let's talk about plants.
Before we start talking about plants being poisonous it's important to look at this in the context of animals as well, very few animals are poisonous however many are venomous. The difference between poisonous and venomous is if an animal bites you and you die, it is venomous, if you bite the animal and you die, it is poisonous!
Some plants are poisonous.
Plants can't run away from predators so they use different methods of defence , some external methods such as thorns, spines, barks or waxes can physically prevent them from being eaten (see picture above of cactus showing both waxy paddles and sharp spines which are modified leaves to defend against being eaten) but mostly they defend themselves internally by using chemical defences.
If the first line of defence is breached, the plant must resort to a different set of defence mechanisms, such as toxins and enzymes. Secondary metabolites are compounds that are not directly derived from photosynthesis and are not necessary for respiration or plant growth and development.
Many metabolites are toxic and can even be lethal to animals that ingest them. Some metabolites are alkaloids, which discourage predators with noxious odours (such as the volatile oils of mint and sage) or repellent tastes (like the bitterness of quinine). Other alkaloids affect herbivores by causing either excessive stimulation (caffeine is one example) or the lethargy associated with opioids. Some compounds become toxic after ingestion; for instance, glycol cyanide in the cassava root releases cyanide only upon ingestion by the herbivore. Foxgloves produce several deadly chemicals, namely cardiac and steroidal glycosides. Ingestion can cause nausea, vomiting, hallucinations, convulsions, or death. - Link
Many of the plants we eat contain these chemical defences and in many cases these are WHY we like to eat these , great examples are herbs and spices, we enjoy the aromatic compounds which the plants produce to defend themselves, a chilli is hot for its protection, not because we like spicy food!
Of particular interest to this subject is the defence mechanisms in seeds and leaves. Plants have coexisted with herbivores for almost 400 million years and in that time have evolved to limit their consumption by predators.
The grains we eat in our diet are seeds and there is no evolutionary advantage for these be eaten by us, especially not to be ground up into flour and baked as the seeds are the plant's offspring and the carriers of its future genetic material.
The defence chemicals in seeds mainly take the form of antinutrients and these particular defence chemicals have the effect on us of blocking the absorption of other nutrients we consume such as iron, calcium and other minerals, hence the name. The major antinutrients found in plant-based foods are:
Phytates, oxalates, saponins, tannins, lectins, and goitrogens.
We will now look at these defence chemicals in more detail.
Phytates (and phytic acids)
Link Phytic acid, or phytate, is found in plant seeds. It serves as the main form of storage for phosphorus in the seeds. Then, when seeds sprout, phytate is broken down and the phosphorus is released. The phosphorus will be used by the young plant. All edible seeds, grains, legumes, and nuts contain phytic acid in varying quantities. Small amounts are also found in roots and tubers.
This chemical affects us both positively and negatively.
The negative effects are that it blocks nutrient absorption especially iron, zinc, calcium and other minerals but only when eaten with foods containing these minerals, not with subsequent meals but this can be an issues for people who consume a lot of these foods or frequently consume them, one of the biggest risk factors is for vegans who do not consume any heme iron as this non-heme iron in plants is not well absorbed and phytates can block this further
The positive effects are that phytates can act as an antioxidant, they are in fact sometimes used as a preservative in processed foods, and this antioxidant effect has been linked to reducing insulin resistance and protecting against certain cancers.
Oxalates (oxalic acid)
Link Oxalic acid is an organic compound found in many plants, including leafy greens, vegetables, fruits, cocoa, nuts, and seeds. In plants, it’s usually bound to minerals, forming oxalate. The terms “oxalic acid” and “oxalate” are used interchangeably in nutrition science.
Oxalates are found significantly in leafy greens and are particularly high in foods such as beet greens, rhubarb, spinach, beets, Swiss chard and even cocoa.
Negative effects: Oxalates cause similar problems to phytates in that they block mineral absorption, a great example of this is spinach, almost none of the calcium in spinach can be absorbed due to the anti nutrient effects of the oxalates which bind to the mineral, these crystals can form kidney stones which are a serious health problem and extremely painful.
Positive effects? It's hard to make a claim that oxalates have anything positive to add to the human diet however for most people they are of little concern but many of the foods that contain them do also contain useful nutrients.
Link Saponins are a group of bitter-tasting chemicals that naturally occur in plants. They get their name from their ability to form soap-like foams in water. The latin word for soap is sapo. Interestingly, saponins are responsible for the foamy substance you see when you soak beans.
Saponins are found in foods such as quinoa, soy, chickpeas, spinach and oats and are there to protect the plant by acting as a natural insecticide, once the cell wall insect's digestion is destroyed by consuming these substances meaning it cannot reproduce.
Like many of these substances, saponins can have a positive or a negative effect on us.
Negative effects of saponins are that due to their 'soap like' nature they can increase intestinal permeability, especially when combined with proteins such as gluten, this 'leaky gut' can lead to a number of autoimmune conditions as the bloodstream is presented with foreign substances the body launches an attack on itself.
The positive effects of saponins are that they decrease blood lipids, lower cancer risks, and lower blood glucose response. A high saponin diet can be used in the inhibition of dental caries and platelet aggregation, in the treatment of hypercalciuria in humans, and as an antidote against acute lead poisoning. Link
Tannins are bitter tasting chemicals produced by plants to deter consumption, they are commonly found in foods such as legume seeds, cider, cereals, cacao, peas, some leafy and green vegetables, coffee, tea, and nuts.
The negative: Tannins have a similar effect as other anti nutrients mentioned above on blocking iron absorption so that a glass of red wine with the steak might taste good but it comes at a price.
High levels of tannin intake from foods such as betel nuts have been associated with mutagenic and carcinogenic effects and inducer, hepatotoxic activity meaning they disrupt liver function. Source
The positive: As with many of these plant compounds there are also positives.Many classes of tannins have antioxidant properties, which have been found to lower total cholesterol, lower blood pressure and stimulate the immune system. They also have antibacterial properties that, among other things, fight tooth decay.
In summary of plant toxins
In the section above we've looked into some of the mechanisms that plants have adapted to defend against being consumed and this has taken place over 400 million years, as we've pointed out we too have adapted to make use of some of these substances so that they are not all a poison.
As with many things, the poison is in the dose and historically we wouldn't have had access to the same plants year round, leaves, seeds, pluses, tubers and the other plant parts we consume would be seasonal. Now we can buy a bag of spinach or quinoa at any time of the year, this combined with the use of chemical fertilisers and pesticides mean that we are subjecting our bodies to a continuous onslaught of defence chemicals from which it needs to defend itself and for some people this leads to autoimmune conditions such as eczema, psoriasis, gut problems and even serious conditions such as MS.
It's impossible to make categorical statements that plants are good or bad for us, the devil is in the details.
What about plants that DO want to be eaten?
Not all plants, or should we say, not all parts of plants try to avoid being eaten, some actually encourage it!
Many plants are reliant on animals to spread their offspring and entice animals into consuming them by making brightly coloured fruits which contain seeds that can remain intact after passing through an animal's digestive system.
Interestingly many fruits do not ripen, change colour and contain sweet tasting sugars until the seeds are fully developed enough to withstand this passage through digestion. This is a perfect symbiotic relationship, the plant gets its genetic code taken to a new location away from the parent plant where it is deposited in a nutrient rich medium called dung! The animal gets to eat sweet rich energy packed fruit that sustains energy and provides other nutrients, it is not in the interest of either to create poison or be poisoned, this is why fruits are considered 'safe' to consume on the softest form of a carnivore diet which is the animal based one.
So this is great, we can eat lots of fruits!
Maybe not lots. In latitudes away from the equator fruits become increasingly seasonal with distance and for this reason our genetics can predispose us to store or use the simple sugars in fruit in different ways, as in Northern Europe where we are, access to these sugars would be seasonal and limited, now of course we can buy any fruit from anywhere in the world in any quantity at any time meaning the situation is quite different. The 'animal based' version of carnivore should still be animal based and not fruit based.
So why are people thriving on a carnivore diet?
If you remember back to the start the conventional carnivore diet eliminates all plants and allows only animal based foods, it is therefore simply an elimination diet and can be a diagnostic tool for autoimmune conditions.
For example, a sufferer of a condition such as psoriasis or eczema trying to ascertain which foods are triggers for their condition could set themselves on a carnivore diet, probably without dairy products. After a few weeks if their condition improves it shows that one or more plant based foods is triggering the autoimmune response.
The literature varies in its suggestion as to how long someone should try the diet before seeing results but a time period of 4-6 weeks seems to be enough to make a change.
After the period of healing individual foods can be reintroduced one at a time to see if there is a reaction, if there is, patients report the reaction is fast and acute giving direct subjective evidence. This experiment can be repeated for various food types, those that don't create a reaction can become part of the diet again if desired.
The Lion Diet
At the very start we identified the variants of the carnivore diet with the most restrictive version being called 'The Lion Diet' and consisting very strictly of just meat from ruminants, meaning beef or lamb, salt and water, absolutely nothing else.
The term was coined by Mikhaila Peterson, daughter of world renowned clinical psychologist Jordan Peterson.
Mikhaila's story is truly extraordinary and she credits this extremely restrictive diet as curing her from very serious illnesses. By the time she was 22, Mikhaila had been diagnosed with rheumatoid arthritis, bipolar disorder, hypersomnia, Lyme disease, psoriasis, and eczema, all cured by eating only beef, salt and water.
On seeing the results his daughter achieved Jordan Peterson tried the diet and credits it for curing his depression and anxiety, easily losing 50 lbs, stopping snoring and reversing degenerative gum disease and psoriasis as well as needing less sleep and gaining sharper mental acuity.
However, he famously stated on Joe Rogan's podcast it's not something he'd recommend lightly as "its boring as hell, plays havoc with your social life and makes travelling really difficult"
The lion diet is about as restrictive as it gets as fatty ruminant meat is probably the only single food that is possible to sustain human life indefinitely with many people reporting living on this diet for not just months but years and even decades and far from suffering ill effects, all report to be better than ever.
Another famous carnivore and influencer in the space is the orthopaedic surgeon and author Shawn Baker.
Dr Baker is an imposing 6'5" hulk of a man who at 56 years old holds various world records in disciplines such as indoor rowing and weight lifting which he credits to over 5 years on a carnivore diet. Dr Baker's approach isn't quite as strict as the Peterson's but is mostly fatty red meat and certainly no vegetables.
Dr Baker's 2019 book simply titled The Carnivore Diet was an Amazon best seller and challenged mainstream medical paradigms concerning what we consider to be 'healthy' foods. He has since launched a website called Revero which brings a scientific data driven approach to applying the carnivore diet to people with chronic illness.
So what are the downsides?
Hopefully we've covered enough detail about how and why it works as an elimination diet but what are the downside and potential pitfalls of this diet? When mentioned the first thing that people get concerned about is what is missing.
Fibre and vitamin C
A strict Carnivore or Lion Diet contains no plants and therefore no fibre which we have been told repeatedly is good for us.
Fibre is a carbohydrate in plant foods that humans can’t digest. There are two types of fibre:
Soluble - Fibre that can be fermented by gut bacteria in the colon to create short chain fatty acids (energy)
Insoluble - Fibre that can’t be broken down by the stomach acids or bacteria in our gut.
So if we can't digest fibre, why is it thought to be good for us?
Fibre feeds bacteria in our gut which produce short chain fatty acids,
Link These short chain fatty acids nourish the cells that line the colon, called colonocytes, and improve gut health as a consequence.
It’s true that colonocytes use short chain fatty acids for nourishment, but only after they’ve converted them into beta hydroxybutyrate, or in other words, ketones. However, not only is fibre not the only source of short chain fatty acids or ketones but a study by Harvard University showed that switching to an animal based diet changes the gut microbiome and produces more short chain fatty acids than a plant based diet.
The other main function of fibre is to add bulk to the stool as it passes through the digestive system and we've been told that this reduces constipation but what does the science say?
Link - Unfortunately, even after half a day of digging through papers on PubMed, you won’t find any significant randomised control trials on the benefits of fibre on gut health.
Funnily enough, the best study on fibre and symptoms of constipation included 63 participants who presented with constipation and were put on high, medium, low and zero fibre diets.
At the beginning of the study, all participants had constipation and strain, with some experiencing bloating, bleeding and pain.
A high fibre diet actually increased the number of symptoms, a reduced fibre diet experienced a modest reduction in symptoms.
So what happened to those on a zero fibre diet…
That's not missing data... Not one patient on the zero fibre diet had any negative symptoms. Not only did they eliminate their symptoms but they had just one bowel movement per day compared to one bowel movement every 6.83 days in the high fibre group.
In fact, one of the problems often reported by people starting the carnivore diet is quite the opposite of constipation, many people report that initially their bowels react by experiencing 'rapid emptying' which has been dubbed 'disaster pants' for obvious reasons! This side effect is quick to pass with subjects reporting normal movements after just a few days as their bodies get used to the extra fats and reduced fibre.
So what about vitamin C
Scurvy is the disease suffered famously by seamen of old whose long voyages would be devoid of fresh foods containing vitamin C and led to the British being called 'Limeys'.
From Wikipedia - The term is thought to have originated in the 1850s as lime-juicer, later shortened to "limey", and originally used as a derogatory word for sailors in the British Royal Navy. Since the beginning of the 19th century, it had been the practice of the Royal Navy to add lemon juice to the sailors' daily ration of grog (watered-down rum). The vitamin C (specifically L-ascorbic acid) in citrus fruits prevented scurvy and helped to make these sailors some of the healthiest of the time. At that time, "lemon" and "lime" were used interchangeably to refer to citrus fruits
So why do modern carnivore diets not cause scurvy?
The answer is simply that fresh meats DO contain vitamin C, however, our seafaring ancestors only had dried meat and as vitamin C is water soluble it is almost completely gone after processing this way.
Red meats contain enough vitamin C to sustain us as this study shows with about 16 mcg/g in grain-fed meat and 25 mcg/g in grass-fed meat.
We're used to thinking about the RDA for Vitamin C being in the milligram levels rather than microgram levels but there's another factor at play here, in the absence of any carbohydrates in the diet our requirement for this vitamin is greatly reduced.
For either glucose (sugar) or vitamin C to enter the cells, they dock onto receptors on the cell surface, which then opens a gateway, allowing them into the cell. And because sugar and vitamin C are similar in chemical structure, they use the same receptors and compete with one another - Link
So should you try the carnivore diet?
We're not here to offer dietary advice or to recommend anything that could conflict with medical conditions but just to present information as we see it.
Many people probably don't need to restrict themselves to this level as there are a great many pleasures to be had from plant based foods, vegetables, fruits grains, herbs and spices offer us a near infinite number of wonderful taste combinations and make both cooking and eating complex and interesting, not to mention the pleasure from good glass of wine or a cold beer.
However if there's something bothering you, something about your health that you can't quite put your finger on that's just not right or if you have a known autoimmune condition it could be worth a try, after all, nothing is a sentence, you can always go back to omnivorism at any time if it's not for you, or you might decide that this is how you want to mostly eat from now on.
I was chronically ill until I was 23 and then suffered from SSRI withdrawal until I was 25. When you’re chronically ill, it’s all encompassing. Nothing else matters as much as being healthy. Sick or injured people have one goal: how to not be sick or injured. The lion diet - How to get started
A thought leader in the keto carnivore movement, Dr. Kiltz believes that an animal-based diet dramatically improves mental clarity, fertility, and health, empowering people to live their best lives. In addition to his own media channels, Dr. Kiltz appears regularly on numerous popular blogs and social media outlets, and has shared his views as a speaker at TEDx. His website here contains a wealth of information about a carnivore diet
Dr Shawn Baker
Shawn Baker is a lifelong multisport elite-level athlete and a medical doctor who served as a combat trauma surgeon and chief of orthopaedics while deployed to Afghanistan with the United States Air Force. His focus in recent years has been on using nutrition as a tool for health, performance, and overall well-being.
His website here is full of individual reports and anecdotes of people who have gained huge benefit from a carnivore diet
Paul Saladino - Carnivore MD
I graduated from medical school at the University of Arizona in Tucson, and completed my residency at the University of Washington in Seattle. After residency, I attained a board certification as a Physician Nutrition Specialist.
I firmly believe that nutritional choices lie at the ROOT of so many chronic illnesses that western medicine deems irreversible.
And I also believe that most chronic illnesses are preventable AND reversible
Pauls version of the carnivore diet is what we referred to at the beginning and is dubbed the animal based diet as he advocates the inclusion of fruits with meats, his website here contains a wealth of information