If we had to design the most harmful diet according to official dogma, it would be the carnivore:
- Very high in protein.
- High in fat, and much of it saturated.
- Without fruits or vegetables.
- Without fiber.
According to the food pyramid of the CSIC (Higher Council of Investigations Scientific), meat is the worst food, only above sweets and eggs. All very scientific.
And yet thousands of people claim that the carnivorous diet helped them regain your health and lose fat, when other approaches had failed.
Today we explain what the carnivorous diet consists of, its possible risks and benefits.
What is the carnivorous diet?
Although there are variants, the concept is simple: eat only animal products.
The most extreme version is limited to red meat and water. Some more moderate include organs and fish. The more flexible alternatives also allow eggs and dairy.
As a concrete example we could take the approach Paleo Keto Diet, with some therapeutic evidence (detail). These are its premises:
- Emphasis on grass-fed meat, using salt as a seasoning.
- Generous organ consumption.
- Two grams of fat for every gram of protein.
- Dairy is not tolerated.
- Depending on the intestinal health of each person, coffee and small amounts of certain spices and fruits are allowed.
Thousands of followers claim that this diet worked for them when classic approaches had failed. They report rapid fat loss, better digestion, less depression, greater mental clarity, and reduced symptoms of multiple autoimmune diseases.
Some have been on the diet for a few months and others have been on the diet for several decades (like Charlene Andersen).
However, scientific evidence is very scarce, and is limited to a handful of case reports documenting improvement in various disorders, from Crohn’s disease (report) to cancer (report).
The main argument of its proponents is that plants are trying to kill us, and technically they are not wrong.
Plants are not interested in being part of your salad, and they contain a huge chemical arsenal to eliminate their enemies (detail): lectins, saponins, oxalates, phytates, alkaloids … 99% of the pesticides we ingest are produced by the plants themselves (study).
For our ancestors, animals were difficult to kill but easy to digest. The opposite was the case with plants. Killing them was easy digesting them had some danger.
However, thousands of years of selecting the least troublesome varieties have turned today’s vegetables into domesticated versions of their wild ancestors. Their poisons strengthen us now by hormesis (detail, detail).
What then is the problem? Individual variability. The dose that is beneficial to the vast majority may be excessive for a small minority.
The dose makes the poison and, in some people, the poisonous dose is very small. If you have a poor combination of genes, dysbiosis, and other factors, you may have a poor tolerance to different plant compounds.
And the fiber?
Fermentable fiber is the favorite food of our bacteria, and its intake is important to maintain a healthy microbiota.
But again we must consider the individual response. If your microbiota is not good, giving it more fiber can magnify the problem. Precisely many of the disorders that improve with the carnivorous diet are due in part to intestinal problems: dysbiosis, SIBO, intestinal permeability …
If you have small intestinal bacterial overgrowth, for example, the fiber in your food could feed the enemy. The same in the case of people with Crohn’s disease or ulcerative colitis, who frequently have some degree of intolerance to fiber.
As Bonnie Leclerc explains, before planting new flowers in your garden, you must remove the weeds. In extreme cases, temporarily limiting the fiber may be the best strategy.
Is there a risk of deficiencies?
Meat is a nutritionally dense food (detail). Provides all essential amino acids and fatty acids, such as Omega 3 (especially grass meat). It is rich in minerals such as phosphorus, iron, zinc or selenium, and provides multiple vitamins of group B.
However, it does contain low amounts of relevant nutrients, such as vitamin C or magnesium. Curiously, deficiencies are not observed in people who have been following the carnivorous diet for many years, but they are still anecdotal.
According to some researchers, recommended daily intakes are designed for high carbohydrate diets, and the requirements would decrease by reducing this macronutrient.
For example, glucose and vitamin C compete for the same transporters to enter cells (detail, detail). Therefore, by reducing blood glucose levels we need less vitamin C. A study in obese people found an increase in vitamin C levels when adopting a ketogenic diet.
By eliminating phytates, it also improves the absorption of minerals such as magnesium (detail, detail), requiring a lower intake.
Another obvious risk is phytonutrients. Although they are not essential for our physiology (and in fact there are no minimum recommended intakes), their consumption benefits us in different ways. We do not know the long-term impact of his absence.
Is it dangerous to eat so much meat?
Reviewing the analytics of people who have been on this diet for years, nothing strange is detected, but they are still isolated cases.
There are no societies that have fed solely on animal products, nor do we have long-term studies. Evolutionarily it is still an experiment, and the result is still uncertain.
The fear of some of the meat is not justified (detail, detail), and we already analyzed at the time the complex relationship between meat and cancer.
That said, a meat-based diet could raise some risks:
- Activating mTOR. MTOR is essential for gaining muscle mass, but an excess can be problematic, especially in sedentary people. The impact would be reduced if the carnivorous diet is carried out in a caloric deficit and / or intermittent fasting is incorporated.
- Iron excess. Iron is necessary, but in excess it can be problematic, especially in men. Luckily, reducing this risk is simple, checking the levels from time to time and making blood donations.
- Toxic compounds. Aggressive preparations, such as barbecue or grill, increase the production of potentially carcinogenic compounds (study), such as heterocyclic amines (AHC) and polycyclic aromatic hydrocarbons (PAH). Although its true impact is unclear, it is advisable to prioritize less aggressive cooking methods.
- TMAO excess. Years ago, a publication in Nature speculated that the intestinal metabolism of carnitine gave rise to a compound called TMAO (detail), which could increase the risk of cardiovascular disease (study). Paradoxically, fish provides even greater amounts of this compound (study, study), and its consumption is almost always associated with cardiovascular benefit (detail). There is much to investigate, but it is not a risk that we should ignore.
- Hormones and antibiotics. Although grass-fed beef is better, conventional beef is not packed with hormones and antibiotics as some believe (detail).
In short, meat is a great food, but its effect depends on the context. The consumption of fruits and vegetables minimizes the possible negative aspects of excess meat, and we don’t really know the long-term impact of eating only meat.
What is the reason for the improvement?
According to some followers of the carnivorous diet, all the benefits they experience are due to eliminating the terrible plant foods.
In especially sensitive people this will be partially true, but surely there are many other aspects. And if we understand the mechanisms, we can design less restrictive strategies that accomplish the same.
Let’s see what could happen when eating a carnivorous diet:
- Caloric deficit. It is not always true, of course, but by relying on very filling foods and such a restrictive diet, you tend to eat less. This will produce fat loss, with all the associated improvements.. Protein will also minimize muscle loss (detail, detail). At its core, it is a kind of PSMF (Protein-Sparing Modified Fast), but if the goal is to lose weight fast, I prefer a more varied ketogenic diet.
- Ketosis. By restricting carbohydrates so much (almost to zero), ketone bodies will rise, experiencing many of the associated benefits: satiety, less general inflammation, mental clarity …
- Bowel rest. The meat is completely absorbed in the small intestine, generating little waste and giving the rest of the digestive tract a breather.
- Reduction of bacterial overgrowth. Limiting the food of invading bacteria would improve various intestinal symptoms, but the same could be achieved with less radical treatments.
- Less sensitivities. By eliminating almost all the suspicious elements (gluten and other lectins, eggs, casein, nuts, fruits …), problems due to unknown sensitivities to any of these compounds would be reduced.
In what cases would it make sense?
If you do not have any health problems, learn to eat well and forget about the carnivorous diet. Although thousands of people follow it, we do not know the possible long-term effects, and I think it is an unnecessary risk.
However, if you have any of the following problems, and you have not improved with other more moderate approaches, an extreme exclusion diet makes sense. In these cases, the potential benefits far outweigh the possible risks:
- Autoimmune diseases. For example, benefits have been reported in cases of rheumatoid arthritis or psoriasis.
- Intestinal disorders such as ulcerative colitis or Crohn’s disease.
- Parasites, fungi, and other invaders, from Candida to Lyme (Borrelia).
- Mental problems such as depression, schizophrenia, or bipolar disorder.
As we saw previously, there are still no studies confirming benefits, and we simply rely on anecdotal cases. It is not optimal, but this is often how science advances, from observation to experimentation. And I repeat, the carnivorous diet would be the last option.
You could carry out a short phase of a carnivorous diet, for example 30 days and, if you notice improvement, gradually transition to a more complete and easy-to-follow diet.
Many times when someone improves their health after a big change they become dogmatic. Think that if that intervention was the only thing that worked for you, it implies that it is always the best option. It’s a mistake.
The reality is that there is great individual variability, and there are no magic recipes for complex disorders.
Unfortunately, some leaders of the meat-eating movement, like Shawn Baker, have become as dogmatic as the vegan preachers. They claim that vegetables are bad and that humans are better adapted to a carnivorous diet.
Physiologically, this is false. We are omnivores, and the best human diets include animals and plants. No society has survived in a wild environment eating only vegetables, but there are no carnivorous tribes.
Thinking that a diet without fruits or vegetables is the best option for the entire population defies reason, and does not fit with the scientific literature.
That said, there are individual cases where an elimination strategy will work best, and the meat-eating diet is a possible solution.