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What Is The Carnivore Diet: Health Myths, Side Effects And Pseudoscience

What Is The Carnivore Diet: Health Myths, Side Effects And Pseudoscience

Is your life not hard enough? Would you like to deplete your body’s reserves and deprive it of essential nutrients to lose a few pounds? Meet the carnivore diet, a fad that's bad for your health, your wallet and your self-esteem.

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The carnivore diet is the shiniest fad diet on the block. It’s not new, it’s not even original, but it is Bear Grylls extreme (though we doubt Bear Grylls would ever endorse this diet). But if you’re into magic beans and conspiracy theories, it might just be the perfect diet for you.

Sadly, your body won’t agree because this diet completely overlooks the body’s essential nutrition needs. It parades pseudoscience as fact, promising that a meat-only diet will cure everything from autism to alcoholism.

To be clear, there is no carnivore diet science. Instead, this fad presents non-specific medical research as proof to convince people that it’s the magic bullet for a six-pack and eternal life. In this article, we review the carnivore diet claims and explain exactly why you should stay away from it.

☝️DISCLAIMER☝This article is for informational purposes only. It is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment.

1. What is a carnivore diet?

The carnivore diet is a zero-carb diet that spreads misinformation about antinutrients in plant foods – a belief shared by many fad diets including the paleo diet and the blood type diet. Lectins, they claim, are evil antinutrients in plants that make people fat.

Say goodbye to fruit, vegetables, grains, starches, nuts, and legumes because the carnivore diet dictates that you can only eat meat, animal fat, and eggs.

Rather than targeting proven causes of obesity, weight gain, and diabetes, like refined sugars and fast food, carnivore diet gurus incorrectly accuse lectins – proteins found in raw beans, lentils and grains. But lectins are eliminated by baking and boiling, which makes them perfectly safe to eat.

However, there's plenty of evidence to suggest that we are not eating enough of these fiber-rich plant foods. Lectins are not a problem. If they were, obesity and diabetes would be very old health problems, but they’re not. These are diseases of our century.


2. The carnivore diet plan: fuel vs macronutrients

The carnivore diet is a more extreme version of the keto diet. The goal is to cut out glucose and turbocharge the body’s fat-burning capabilities to replace the lost fuel and make up for the lack of glucose - a process called ketogenesis.

The body stores excess carbs as fat. When blood sugar levels drop, it starts to break down fat stores, and cells can then turn fatty acids into ketones - an alternative source of energy for most cells (except the liver and red blood cells).

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However, this theory conveniently forgets that your body doesn't just need energy - it needs other stuff too. Every chemical reaction is regulated by a range of nutrients, including sodium, potassium, calcium, vitamins, and antioxidants. We get most of these from our diet.

So when you cut out food groups, you’re restricting your micronutrient intake too. Let's take the vegan diet as an example: nutrient deficiencies aren’t caused by eating too many vegetables, they’re caused by cutting out whole food groups. The same logic applies to the carnivore diet.

Dietary fiber: a carnivore diet myth

Proponents advocate with cult-like fanaticism that your body doesn’t need fiber. This is totally incorrect. Fiber is a critical part of a healthy diet, and there's plenty of science to prove it.

Here are some important dietary fiber benefits:

  • preventing constipation - a common problem in keto-based diets.
  • removing excess cholesterols and bile acids from your body
  • regulating blood glucose and blood lipid levels
  • supporting immune system health
  • feeding the essential bacteria in your gut microbiome
This last point is not to be underestimated – scientists even call this ecosystem of microorganisms a ‘new organ’. Good bacteria in your gut help prevent infections, and they produce vital nutrients (like butyrate) that fuel the cells of your gut lining.

A happy and balanced gut microbiome even helps regulate body weight, but these microbes thrive on prebiotics – dietary fibers and nutrients found in plants – which are often completely absent from the carnivore diet.


Carbs: flawed carnivore diet reasoning

Carbs are the devil in this diet, a position that defies common sense: your body depends on carbs for energy. Your brain is mainly fueled by glucose and carbs give your muscles energy, so when you go cold turkey, your brain doesn’t work as well, neither do your muscles because they are hungry.

Unfortunately, carbs are very unpopular nowadays because they have been linked to serious deadly diseases: obesity, diabetes, and heart disease. But not all carbs are bad! Refined carbs in fast food, sugary beverages, and chocolate bars are nothing like the carbs in whole grains, beans, fruit and veg.

In the animal kingdom, even hypercarnivores eat plants, and the mid-level carnivore diet is 30–50% plant-based. So what's the fuss?

Whole, unprocessed carbohydrates are good for your body. They are packed with nutrients, fibers, and resistant starches that make you feel fuller for longer. Complex carbs keep your blood sugar levels stable, while providing nutrition for your cells and your gut bacteria.

The carnivore diet would have you believe that all carbs are evil and your carb cravings must be eliminated. That’s simply not true. Your body would benefit more from a balanced diet with whole grains, beans, fruit and vegetables, than bingeing on meat, bacon and eggs.

As microbiome expert Miguel Torribio-Mateas points out: “Scientists have found that when an Inuit swaps carnivore meals for a typical American diet (like tacos or fried chicken with fries), their microbiome becomes Western very rapidly, and their risk of becoming obese and diabetic increases too.”

3. Carnivore diet menu

Now, let’s take a look at the list of foods on the carnivore diet and think about how this will affect your digestion and your monthly budget. Carnivore diet gurus recommend that you only choose the highest quality of meat, such as grass-fed beef, and wild line-caught salmon.

Carnivore diet food list

  • red meat
  • white meat
  • offal (i.e., organ meat)
  • animal fat (i.e., lard)
  • poultry
  • fish
  • seafood
  • eggs
  • dairy (optional)

A sample carnivore diet plan

Get ready for very limited variation in your daily diet. Carnivore diet recipes allow you to season your meat with spices and cook it in fat, which is perfect if you enjoy heart burn, indigestion, or constipation.

And while we all occasionally dream about bingeing on bacon, take a look at this hypothetical carnivore diet meal plan and ask yourself how long you could really survive on meat alone.

Breakfast Lunch Snacks Dinner
Eggs and bacon Shrimp and beef Pork rinds Fatty steak
Sausage Boiled eggs with sour cream Cheese slices Beef burger w/ cheese (no bun)
Pork belly Slow-cooked beef Bone marrow Roast fish with tallow (beef fat)

Like other restrictive fads, a zero-carb diet will likely fuel cravings for other foods (probably junk food). This increases the risk of bingeing, unnecessary shame, and abandoning your goal of getting healthier. Plus, restrictive diets are associated with eating disorder tendencies.


4. Carnivore diet benefits

There is a treasure trove of seemingly magical weight loss carnivore diet before and after transformations online. The same websites claim that people have recovered from every kind of imaginable disease too. And yet, there's no evidence to suggest that the carnivore diet has any health benefits whatsoever.

Carnivore diet weight loss

There are no proven carnivore diet benefits by Thought Catalog for Unsplash
There are no proven carnivore diet benefits

Yes, you can lose weight on the carnivore diet because it is an extreme diet that deprives you of adequate nutrition. However, extreme weight loss also comes with a yoyo effect. Sure, you lose the weight, but many people end up putting it back on and getting even heavier.

5. Carnivore diet side effects

There are short-term and long-term carnivore diet side effects. At first, you may experience a set of symptoms known as the keto flu that are caused by depriving your body of glucose.

Short-term side effects

Nausea Vomiting
Headache Fluid imbalances
Fatigue Dizziness
Insomnia Constipation

Short-term symptoms last a few days to a few weeks and are unpleasant. They can result in fluid and electrolyte imbalances. These are serious because they are a sign that your body lacks essential micronutrients that allow your cells to function normally.


Constipation: keto and meat-only diets are severely disruptive to your digestive system. At first, you may develop constipation as a side effect of the carnivore diet because there is no fiber to add mass and water to your stool.

Diarrhea is also a well-known side effect of carnivore and keto diets. Some bodies just can’t handle the excessively fatty diet, which results in runny, greasy stools. Plus, the lack of plant foods starves good bacteria in the gut, making it more susceptible to invaders that can upset your digestion.

Heartburn: people with heartburn who are taking PPI medication (proton-pump inhibitors) that stop acid production in the stomach will also have problems. Stomach acid is essential for digesting meat and fat, but PPIs reduce stomach acidity and prevent your stomach from emptying as efficiently as it should.

Long-term side effects

Has everyone forgotten that bears love berries, new shoots, and honey? by Zdeněk Macháček for Unsplash
Has everyone forgotten that bears love berries, new shoots, and honey?

There are also many serious, long-term side effects that should not be overlooked. We all think we are relatively invincible until we get sick, but making smart choices today is the best way to stay healthy.

Hepatic steatosis Fatty liver disease is caused by fat build-up in the liver.
Hypoproteinemia Abnormally low blood protein levels can be life-threatening.
Kidney stones Painful mineral and acid salt deposits can block the urinary tract.
Nutrient deficiencies Vitamin and mineral deficiencies have very serious side effects.

The final word on the carnivore diet

The carnivore diet is a fad based on pseudoscience and effective marketing, so please don’t believe the carnivore diet before and after photos. By cutting out whole food groups from your diet, you will deprive your body of essential nutrients.

Extreme dieting is damaging for the body and your mind, putting you at increased risk of disordered eating and long-term health problems. There’s also a good chance that you’ll put that weight right back on because you can’t be a carnivore forever.

Leigh Stewart
Leigh Stewart Head of Atlas Biomed content, trained chef and avid fermenter of edible bacteria.

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