So I can debunk this as a healthy diet simply using commonly known facts. My first thought was where are they getting their energy if not from carbs? As I've documented before, carbs are the body's default choice of energy. It only runs on other energy, like fat, when it runs out of carbs. Well, most meat contains very little, if any, carbs. I believe eggs have a bit of carbs in them, but certainly not enough to supply one's energy needs.
Then it dawned on me, this diet has one running on fat, just like the Keto Diet. Unlike the Keto Diet, however, there are no vegetables at all. Zilch. It is an all meat diet, all the time. That has a couple of huge problems.
1. There will be a serious lack of vitamins, some key ones, in this diet.
Let's look at the nutritional value of various meats. First up: 3 oz of beef.
There is a definite danger of scurvy with this meat. Where's the vitamin C? Also, no vitamin A. Vitamins E along with any others not mentioned here are totally absent. Bye bye antioxidants. The only vitamins here are B12 (Cobalamin) and B6, and out of the minerals, a little iron, with a touch of magnesium.
Notice also that beef has zero dietary fiber. What it does have is 25% of ones cholesterol intake. Remember, this is just 3 oz. of beef. Most people eat at least 4 or more oz. in a single meal. Now, let's look at 1 cup of chopped chicken breast.
Here we have a similar vitamin profile, except with chicken you get a lot more B6 and a lot less B12. And more magnesium. Yet, still no vitamins C, A, E, and other important vitamins. Again, no dietary fiber, and a whopping 39% of one's daily intake of cholesterol.
"But Rick, you're not mentioning the big amount of protein there." That's right, because I figured that was so well known it wasn't worth mentioning. However, notice here that 43 g of protein is 86% of one's daily needs as established by the FDA. In other words, in this one cup of chicken, you have all the protein your body needs in a standard 2000 calorie diet. Keep in mind, this is just one cup. Someone eating a carnivore diet will get way, way more protein than their body could possibly use. Which means most of it will simply get expelled in your waste.
Next, let's look at a pork chop, 219 g of pork.
Here we have the same profile, again, adjusted for some more B12, more B6, same magnesium as chicken, this one though throws in some calcium as well. Missing, again, is any of vitamins A, C, E and dietary fiber, but plenty of cholesterol--a huge 57% of one's needed daily intake--and protein. One pork chop has 104% of a 2000 calorie diet's worth of protein!
I forgot to mention above that protein can increase one's acid levels if too much gets in the blood. The body, btw, compensates for it dissolving bone into one's blood stream. It is the basis for the high osteoporosis rates of groups like the Eskimos who have a high protein diet due to eating a lot of meat.
So, as you can see, on a carnivore diet, one is missing a lot of essential nutrients that are needed to prevent diseases like scurvy and the other such diseases known to exist from vitamin deficiencies.
Also, in all meat there is a problem of missing dietary fiber. This is an important component of anyone's diet in feeding one's gut bacterial to keep that healthy. It is vital for avoiding constipation, which I can foresee most anyone on this diet having a problem with. One cannot forgo all fiber and expect to stay healthy.
"But Rick, we have supplements for that kind of thing." Yes, one could take supplements like multivitamins and fiber pills. Two issues with this approach.
One, aside from the error of taking a pill for your vitamins, you are getting a combination of extracts, artificially combined, with no fiber. In other words, most vitamins you take pass right through you with minimal absorption. Most of your vitamins will go right into the toilet. Additionally, there is a study showing that the bioavailability of multivitamins are not well established:
Although the bioavailability information on single doses of individual vitamins and minerals is fairly well established, the bioavailability of MVMs is slightly more complex because of various nutrient-nutrient interactions. The standardization of testing for MVM bioavailability may prove difficult indeed, because each micronutrient is unique in its bioavailability characteristics.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3823510/
Two, part of the carnivore diet's premise is this is how ancient man used to eat. Aside from the scientific evidence showing that early man used to be a carnivore to be a fallacy, ancient man could not survive on purely eating only animals. The natural selection would have weeded them out long ago due to the lack of certain vitamins in their diet. They couldn't have taken multivitamins back then to offset the lack of important vitamins. Yet, they survived, primarily because as archaeology shows, they were primarily plant eaters. In other words, they were more gathers than they were hunters.
So supplements are not ideal at best. It is a gamble that you are getting the vitamins you need to prevent diseases and be healthy by taking a multivitamin. The best way to get those vitamins is from whole foods. But that is impossible to do on a strictly carnivore diet.
2. Going into ketoacidosis is a big problem with the carnivore diet.
Okay, we need to get back to our basic energy sources and how they work. First off, there are three potential sources of energy: carbs, fat, and protein. Carbs is what our body is designed to operate on in default status. In other words, that is the first energy source our body looks to use, because at the foundation of our cells, they run on glucose. The body is designed to operate on that fuel, and so it looks for nutrients that are predominately made up of glucose, like starches, because those are easiest to break down into glucose.The next easiest fuel to break down into glucose is fat. It does this by converting fat into triglycerides, and then converting that into glucose. It is a more difficult process than breaking down starches, and has the added problem of producing ketones as a by-product, that get expelled from the body through one's urine and breath. Ketones are also used as fuel for the brain since fat can't pass the blood-brain barrier.
The body can also convert protein into glucose but it is a much more complex process which the body reluctantly gives up. It is rarely ever used as a primary energy source because 1. You need protein to repair damaged cells, 2. your body doesn't store protein, 3. the process is more complicated to produce glucose from protein than from carbs, 4 There are numerous problems that result for the body in burning protein as fuel, including bone damage and wasting away of your muscles.
So, as the article I linked to about using ketones as fuel for the brain, even that is a limited fuel for the brain. It can only survive on ketones and glucose created from that process for a set period of time before that runs out due to the metabolic needed chemicals to burn ketones being drained. Then one risks going too far into ketoacidosis, a fatal condition where too many ketones build up in the body.
This is what a carnivore diet has to end up in, is ketoacidosis, due to the lack of carbs in the diet. It is natural for fat to become the primary source of energy when there are no carbs, which means the liver is put under stress converting the fat into energy that the brain can use. Once glycogen stores are used up, one risk burning more protein thus resulting in muscle loss and bone loss. Especially since we know a more acidic environment is created by eating fat and protein as one's main energy intake.
This is aside from the other documented problems of a big meat diet in promoting cardiovascular disease, diabetes, and cancer growth that I've expounded on in previous articles.
Therefore, I would label the carnivore diet the death diet. Even most Paleo folk recognize the advantages of vegetables in one's diet. No, the carnivore diet is a fad diet, not based on science, but upon the fake news produced by the beef, chicken, and pork industries. Don't buy into it, or you may be buying into your death.