The Carnivore Diet
By Ryan Heeney / February 7th, 2024
Would it be possible for a human to eat only meat and nothing else?
Well there's a group of meat-eating carnivores that have arrived on the nutrition scene and they're saying that not only is a diet of pure meat possible, but that it's actually optimal, and from all evidence available, they are practicing what they preach.
What I think I can do is attempt to make sense of the positive results which some have experienced from this diet. Then, explore why this diet ultimately fails.
The benefits of this diet would be as follows:
1. Very low PUFA (polyunsaturated fat) - In my opinion this is a big one. Eating just beef would make most of the fat they take in highly saturated. I found it interesting that most carnivores mention both chicken and salmon didn't work as well for her, which in my opinion would make sense in that the PUFA would most likely cause an inflammatory response.
2. No gluten - This one would be big as well and would make sense because gluten can be a very inflammatory food for lots of people and cause gut irritation. Many people that switch over to carnivore have preexisting celiac disease as well, so gluten for her would be a definite no-go.
3. No starch - In people with compromised metabolisms, starches can increase endotoxin in the gut, leading to an inflammatory response.
4. No problematic plants, grains or seeds - Free of the ant-nutrients and irritants plants, grains and seeds contain, along with their fiber. Some carnivore types mention for example, that apples gave her low back pain and other problems associated with inflammation and she expressed some confusion at that, as did Joe. But apples are known for their high pectin content, which can be very problematic for people unless the apple is cooked well and peeled. The same can go for many fruits and vegetables and my article here can help make sense of a lot of that. I would be curious at how fresh squeezed, pulp-free orange juice might react with her, for example, which is free of most problematic substances.
5. Adequate Protein - Adequate protein will keep the liver healthy and stress hormones like estrogen, low.
6. Free of "processed foods" that contain potential gut or intestinal irritants - Carrageenan, gums, thickeners and many other problem substances found in packaged foods can also cause great digestive distress and cause other systemic health issues.
7. Adequate dietary cholesterol - The hormone from which all other hormones in the body are made. Cholesterol is important for the production of youth hormones like testosterone, progesterone and pregnenolone. These are the hormones that keep us youthful, decrease body fat, and keep our metabolism high as we age.
8. Very low Vitamin C requirements - Since there is evidence that glucose and Vitamin C compete in the body, the meat diet becomes possible even in the face of the fact that meat contains very low levels of Vitamin C. This phenomenon is thought by those in the Carnivore Diet community, to be the reason cultures have been able to survive and pure meat diets without being victim to scurvy.
So is this the holy-grail of diets? With so many positives, could there any downsides to eating just beef, salt and water?
Yes, I do believe there are downsides:
1. Lack of adequate carbohydrate (especially in the form of sugar) - In the body there is a metabolic process known as the "Randle Cycle". Despite it's name it isn't really a cycle at all but more our body's preference to burn either sugar or fat as it's main fuel source. When the cell is forced to burn free fatty acids (fat) as its main fuel source, this actually inhibits the use of glucose (sugar), which is the cells preferred energy source. Burning primarily fat for fuel sounds like it would be the optimal mode for our body to operate in, but it's actually isn't. Burning fat for fuel causes our stress hormones to rise, the good youth hormones to fall, and is very stressful on the body. The use of sugar as our main fuel source, is a much better option for staying healthy, despite what your "trainer" might tell you. Low carb diets, by default, will push the body into the mode of burning fat for fuel (since you're eating low carbohydrate, fat is the only other macronutrient able to make up your caloric needs after protein needs are met). To ensure you stay in an oxidative metabolism (sugar burning), its helpful to eat enough carbohydrate (fruits, juices, honey, potatoes, rice, etc.) eat regularly and keep the diet low in polyunsaturated fats.
The Randle Cycle will be a future article in itself but for now I would think of it this way: The type of metabolism your body is in (burning fat for fuel or burning sugar for fuel) is like predicting who will win in a race, a car a 200 horsepower-engine or a car with a 700 horsepower-engine. Yes, there are going to be other small details that make either car different, like the types of tires each may have or how much more aerodynamic one is more than the other, but the power of the engine is going to overwhelmingly be the most important factor in who wins the race. In this case, a sugar burning metabolism is the vehicle with the 700 horsepower-engine. f you get your body into the right metabolism, everything else will follow much more efficiently.
2. Lack of calcium - An extremely important mineral that helps keep stress hormones low (parathyroid hormone for example) and keeps metabolism high. Besides bone and teeth health, this mineral is crucial for cell function
3. Lack of gelatin to balance out muscle meat - To further blunt the effects of cortisol, gelatin along with the anti-inflammatory amino acids it contains, should be eaten whenever muscle meat of any kind is eaten. This includes steak, chicken breast, fish, etc. Great Lakes Hydrolized Collagen is a great brand if you wish to supplement in powder form and works great in juice.
4. Lack of other important micronutrients - Nutrients found in seafood, dairy, fruit, and organ meats would be necessary be replete in all other micronutrients like selenium, magnesium, potassium, vitamins A, D, E and K, etc.
5. An increase in the stress hormones including cortisol and adrenaline - A lot of times people report feeling extremely good after going low carb or going on a diet in general. They experience a feeling of extreme alertness and seemingly have energy to burn all day, everyday. While at first this seems like a great benefit, they are most likely experiencing this under the effects of cortisol and adrenaline. What happens weeks, months or years in the future is the inevitable crash. Balancing protein with a carbohydrate will minimize the negative effects of these stress hormones.
So as a whole, the diet itself has quite a few benefits when weighed against potential downsides, and while I do think it is possible to do fairly well in the short term and possibly even the medium term (months). Low carbohydrate diets, in my opinion, do not do well in the long term (past 2-3 years). The "cortisol high" will begin to fade, and these stress hormones will begin to take their toll.
If I had to give general nutrition advice, though, excluding any potential unique cases, I would say to try and final the situation that is optimal and not to get “get by”. A point that I often argue is, why subsist on a diet that might score a B when you could go for an A+? Yes, if your current health is an F, a diet that could bring you to a B will be a big improvement, but that does not mean that that diet is optimal. While a carnivore diet may have massively improved someones health, and while their diet may be possible to get by on, and even do well on, I think the average carnivore eater could do much better.
I believe your best bet will be a diet that is:
Adequate in proper carbohydrate (in the form of fruit, juice, potatoes, white rice, sourdough bread)
Low in polyunsaturated fat
Sufficient calcium (from good dairy sources or in the form of supplemental calcium carbonate)
Adequate in protein (from good animal sources, seafood, milk or muscle meat balanced with gelatin.=
Contains salt to your taste preferences
Adequate in fiber from easily digestible fruits, daily raw carrot, or well-cooked mushrooms
What “adequate” means for each will depend person to person. A resting pulse of 85 and a body temperature of 98.6 degrees Fahrenheit will give you a good idea your metabolism is working the way it should. Just simply going by how you feel can be helpful as well; are you sleeping well, how are your energy levels, warm hands and feet, healthy libido, able to relax, etc.
A lot of "diets" come and go, and I'm glad they work for some, but I think a more nuanced approach towards nutrition is often warranted. While many diets get people by, I often think there are more optimal solutions. Diets as restrictive as an "all meat diet" can be too restricitive in my opinion.
Note: Recently on a famous podcast, two carnivores we’re talking, and the question came up"why has everyone become so fat and stupid, what has changed?", and he adds that whatever it might be, he believes it to be diet related. They came to conclusion that it's "probably carbohydrates". But the data shows that carbohydrate consumption is not the metric that has changed as of recently. In the past 100 years, vegetable oil consumption has gone up over 1,400%. That is 14 times what we previously consumed. Overall PUFA consumption in grams in the U.S. has nearly tripled. What has changed in a massive way, is the amount of polyunsaturated fat we have been consuming.
While sugar consumption among the obese has actually fallen as of lately:
