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Not Getting Enough Fat on the Carnivore Diet: Side Effects and Remedies

By Liam McAuliffe Updated on

The carnivore diet is, by default a high-fat, low-carb way of eating–meat is essentially a zero-carb food. Yet because we’ve been trained by nutritional misinformation to fear fat, many people suffer the pitfall of eating too little fat on the carnivore diet. When you’re not getting enough fat on carnivore, a slew of issues can arise, including the uncomfortable and potentially dangerous symptoms of protein poisoning. 

In this artilce, we’ll take a closer look at what happens when you’re not getting enough fat on carnivore, and some easy tips to help you boost your fat intake. 

Table of Contents

Not Getting Enough on Carnivore: Fast Facts

The human body is ruled by metabolic constraints when it comes to the percentage of calories we can get from protein. 

When you cut carbs to less than 10% of your diet–as is the case for nearly every carnivore dieter– you need to get at least  70-80% of your calories from fat. only Only 10-30% of caloreis come from protein. 

Not getting enough fat on the carnivore diet can result in various issues, including: 

  • Persistent hunger
  • Intense cravings for carbohydrates
  • Risk of protein poisoning, also known as rabbit starvation
  • Digestive disturbances like diarrhea or constipation
  • Potential deficiencies in essential micronutrients
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Humans are Designed to Eat Mostly Fat 

To better understand the repercussions of inadequate fat consumption on the carnivore diet, it’s vital to grasp the central role fat has played in human evolution and physiology.

For nearly two million years, preceding the advent of agriculture, humans thrived primarily on high-fat, low-carb diets. Our ancestors’ ability to flourish on fatty meats fueled the development of our larger brains, distinguishing us from our primate relatives.

Researchers like Miki Ben-Dor and Amber O’Hearn emphasize that our evolutionary history is deeply intertwined with a carnivorous diet rich in fatty animal products. This genetic predisposition for fat consumption is reflected in our bodies’ physiological makeup and metabolic preferences. 

  • We store far more fat on our bodies (to be used as fuel) than any of our primate relatives
  • We enter ketosis in non-starvation states
  • Fatty meat provides the near-perfect balance of macro and micronutrients for our specific physiological needs. We evolved and optimized as meat eaters. 
  • Our digestive tract is much shorter than our primate ancestors. Our short, highly acidic digestive tract is designed to digest meat. The long, less acidic, digestive tract of primates is designed to ferment plant fibers into fatty acids. In both cases fat becomes the main macro nutrient. The difference is that humans evolved to get it from other animals, not to create it within ourselves.
  • Our brains are massive and demand 20% of our caloric energy. We were able to evolve our brains once we discovered the ready-made fat loaded with brain-specific fat-soluble vitamins from other animals. The brains of our primate ancestors use only around 8% of caloric energy because so much energy goes into fermenting fiber into fat.  [1]


Source:  Dr Miki Ben Dor

Protein Poisoning on the Carnivore Diet

Getting more than 50% of your calories from protein will put you at risk for protein poisoning. 

When the body metabolizes protein, it produces waste substances such as ammonia and urea. When not getting enough fat on carnivore, excessive protein can overwhelm the body’s ability to process and eliminate these waste products efficiently, leading to elevated levels of urea in the blood. High levels of urea can be toxic to the kidneys, which are responsible for filtering and excreting waste products.

Symptoms of protein poisoning include [3] :

  • Nausea
  • Diarrhea
  • Fatigue
  • Hyperaminoacidemia: Elevated levels of amino acids in the blood that can lead to liver, kidney, and hormonal disorders. 
  • Hyperammonemia: Elevated levels of ammonia in the blood that can lead to liver and intestinal problems.
  • Hyperinsulinemia: Elevated levels of insulin that can lead to numerous hormonal imbalances.
  • In extreme cases, can result in death after 2-4 weeks of prolonged protein poisoning

Clinically Observed Protein Poisoning on a Carnivore Diet

In the early 1900s, Arctic explorer and Harvard trained ethnologist Vilhajlmur Stefansson spent years living with the inuit, where he learned to thrive on a traditional carnivore diet of mostly animal fats and organs. 

Upon returning to America, Stefansson wanted to demonstrate the health benefits of the diet to a Western world that thought he was crazy. 

To add legitimacy to his demonstration, Stefansson practiced the carnivore diet with a friend while under observation New York’s Bellevue hospital for a year.

During that year, there was only a single time that the men experienced illness, and it occurred when the doctors overseeing them asked them to experiment by eating only lean meat.  

Not getting enough fat on his carnivore diet caused, as Steffanson described, “diarrhea and a feeling of general baffling discomfort.” 

Fortunately, Steffanson and his friend quickly reversed their symptoms with one feast loaded with fatty beef brains fried in bacon fat alongside sirloin steak.

This situation led the observing doctors to declare that a ratio of 3 parts fat to 1 part protein was ideal on the carnivore diet. To this day, this ratio stands as the rule of thumb for all modern low-carb, high-fat diets. 

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Digestive Issues

For most people the most obvious manifestation of not getting enough fat on the carnivore diet will be digestive issues. 

Carnivore constipation and diarrhea can both be addressed by increasing fat intake while making sure you’re getting enough water and salt

Micronutrient Deficiencies 

Fat-soluble vitamins, including A, D, E, and the unique meat-specific vitamin K2, play crucial roles in supporting essential bodily functions such as immune response, hormonal balance, and gut health.

Vitamins A and D directly influence the production of bile acids, which are vital for metabolizing the increased fat consumption characteristic of a carnivore diet. These nutrients are predominantly obtained from meats rich in beneficial saturated fats.

One 2015 study found that 80% of participants with IBS, and over 30% of healthy participants were deficient in vitamin D. [5]

Given that many individuals turn to the carnivore diet to manage digestive issues like IBS, it’s plausible that they may already have insufficient levels of these essential fat-soluble vitamins. 

Carb Addiction and Always Feeling Hungry 

The typical American diet is inundated with carbohydrates from processed grains and added sugars. Research suggests that carbohydrates can trigger neurotransmitters and activate the brain’s reward centers in a manner akin to addictive substances such as alcohol and cocaine.5  

Carb addiction can contribute to a host of serious metabolic issues, including diabetes, infertility, heart disease, and various cancers.

Fortunately, unlike carbohydrates, fat consumed independently is not associated with addictive properties. In fact, fat has a satiating effect, meaning it helps us feel full for longer periods, reducing cravings for additional food.[6]

Not getting enough fat on the carnivore diet removes sugar without providing the satiety benefits of fat. This can intensify cravings for carbs, increasing the likelihood of indulging in highly processed and carb-laden junk food.

carb addiction cycle diagram

How to Get Enough Fat on Carnivore 

Though not getting enough fat can be a serious issue, on carnivore, it’s remarkably easy to increase your fat intake.

Build your meals around fatty cuts of meat, including

Cook and slather your meats in animal fats, including

What Happens if You Don’t Eat Enough Fat on the Carnivore Diet? The Bottomline

The carnivore diet is essentially a zero carb way of eating. When reducing carbohydrates, not getting enough fat can lead to potentially serious issues stemming from an excessive reliance on protein.

The human body has a finite capacity to derive energy from protein, typically between 35% and 50% of total caloric intake. Exceeding this threshold can lead to a condition known as protein poisoning and digestive discomforts such as diarrhea, bloating, and constipation.

Furthermore, insufficient fat intake deprives the body of a highly satiating nutrient, potentially exacerbating cravings for carbohydrates, particularly during the initial phases of adopting the carnivore lifestyle.

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