The zero carb philosophy is based on the words of Vilhjalmur Stefansson during his time staying with the Inuit people, his subsequent year-long all meat diet study at Bellevue Hospital, and the words of Owsley Stanley aka 'theBear'; and states that a diet of just fatty muscle meat is not only healthy but optimal, and that organs meats and other animal foods are completely unnecessary. In this post I will show that this is utter fantasy.
The main issue of eating just fatty muscle meat and no other animal foods is the deficiency this will cause. While muscle meat is rich in many vital nutrients it is completely lacking in retinol (vitamin A) which is the biggest concern; but muscle meat is also very low in copper, calcium, magnesium, and sodium, and low in potassium, selenium, vitamins B1 and B5, and the amino acids glycine and proline. These nutrients are easily found in other animal food: Egg yolks, dairy, and liver are rich in vitamin A; liver (except pork liver), kidneys, heart for copper; bone broth for calcium and magnesium (though supplementing magnesium is also advisable due to water filtration); unrefined salt for sodium; potassium salt for potassium; kidneys for selenium; liver, and pork for vitamin B1; liver, kidneys, and eggs for vitamin B5; and gelatin for glycine and proline. In essence, you need to eat the whole animal (or at least liver, and gelatin-rich bone broths in addition to fatty muscle meat, and to a lesser extent kidneys and the other organs) for complete balanced nutrition.
If you read the Bellevue Study, you'll quickly see that Stefansson ate many different organs: "The meat used included beef, lamb, veal, pork, and chicken. The parts used were muscle, liver, kidney, brain, bone marrow, bacon, and fat. While on lecture trips V. S. occasionally ate a few eggs and a little butter when meat was not readily obtainable". When he was recovering from the high-protein experiment, which only lasted two days (where the scientists conducting the experiment wanted to see what would happen if lean instead of fatty meat was eaten (protein was eaten at 45% of total calories, rather than the usual 20%), his food of choice for the recovery was brains fried in bacon grease! You can read the study for yourself here. As Stefansson ate organs and bone marrow and therefore he can't be used as proof that just fatty muscle meat is enough.
When Stefansson lived with the Inuit he did rightly point out that the Inuit did not eat the liver of the animals they killed. Weston Price also stayed with the Inuit, and as he actually tested the foods they ate to see what nutrients they were getting and from where: he remarks that blubber, of which the Inuit eat a great deal, was extremely rich in vitamin, so they didn't need liver as well! Further-more the liver of their prey would be toxic, as it is too rich in vitamin A, many people know that polar bear and dog liver's are toxic too us, all carnivorous animal's live are. Seals, the main food of the Inuit, eat a lot of fish, including the fish's liver, so have a large amount of retinol in their diet; cod liver oil is very rich in vitamin A but not at a toxic levels, the Inuit eat fish livers. The Inuit did NOT avoid eating liver because it is 'too carby' as theBear claims, which is insane as an ounce of liver adds a measly __g of carbs. This means the Inuit have to use other sources for vitamin A than their prey's liver to avoid toxicity, so they go for blubber instead.
Here's a couple of videos showing Inuit people eating every part of the animal they can: here ("I can't wait to eat the brain", ) and here. So Stefansson's claims that the Inuit do not eat any organs and instead feed them to their dogs is clearly not representative.
theBear was the main creator of the modern day ZC idea by posting on the Active Low-Carber forums, about his experience on the zero carb diet. He reports that his diet for the last nearly half century was made up of fatty muscle meat, eggs, butter, cheese, coffee, with occasional protein powders and other animal foods. So even theBear can't be used as an example of the modern day claimes by the zero carb community that all you need is fatty muscle meat and water, as he regularly ate eggs and dairy. My 'beef', as it were, is with pure fatty muscle meat diets.
theBear repeatedly shows that he has limitied knowledge of nutrition and frequently gets things wrong:
|"Vitamins. that is easy, there are virtually no sources of any vitamins to be in vegetation (which is why all vitamin supplements are synthetic), but all are found in abundance in meat. For example no source of A other than animal liver exists."||Vegetables do contain vitamins, you can get supplements made from plants instead of synthetically, but he's right that vitamins are more concentrated in animal foods, they're also more bio-available due to lack of anti-nutrients such as fibre or phytic acid. There are other sources of vitamin A, even restricting to just sources of retinol, which is preformed vitamin A rather than beta-carotene, liver is not the only source: egg yolks and dairy (butter, cream, cheese, etc) are two such examples. But when looking at meat as in a dead animal rather than all animal foods, yes liver is the best source; grass-fed animal fats though will have beta-carotene in them which is what makes grass-fed animal fats yellow, but conversion of beta-carotene to retinol is non-exist in 45% of the population and extremely poor in the rest of the population even when highly deficient in retinol.|
|"The one meat that needs to be eaten sparingly is liver, which contains a lot of starch (glycogen) and vit. A which is toxic in excess. Excess may be as little as one ounce of the liver of an animal feeding on fish."||100g of beef liver contains 3.9g of carbohydrates, 100g lamb liver 1.8g, this is hardly a lot when all you need for vitamin A requirement is one or two ounces a day. Vitamin A is only toxic if you're deficient in vitamin D. Animals feeding on fish will be getting lots of vitamin A in their diets (fish livers are very rich sources of vitamin A, cod liver oil is one of the most concentrated sources per gram) so their livers will be extremely rich in it, we know that the livers of polar bears and dogs have too much vitamin A for us to eat, but the livers of herbivores are perfectly safe to eat.|
|"'Excess' dietary protein is broken down and discarded, never converted to glucose except in an emergency- such as under heavy and extensive fasting- and then only after all the stored glycogen in liver and muscle has been converted first. The liver under these circumstances only produces from protein the exact amount necessary to maintain the normal level. Only dietary intake can drive the blood glucose level above your baseline."||Protein is converted to glucose (via gluconeogenesis) all the time, even on a high carb diet and there's plenty of glycogen. The liver can and sometimes does make too much glucose from protein and raises your blood glucose level, many people low/zero carb experience elevated blood glucose levels after eating too much protein. Diabetics have it even worse, as their liver is less sensitive to insulin (or insulin is lacking) and so makes a huge amount of glucose via gluconeogenesis, sometimes such that it uses up all dietary protein and thus leads to muscle wasting. Phinney and Volek's research shows that plenty of glucose can be made from gluconeogenesis, which along with using glycerol from triglycerides (fats) to make glucose, can provide up to 200 grams per day. Those with diabetes can't turn down this production of glucose down, which is why they can experience severe hyperglycaemia even while fasting.|
For more on gluconeogenesis: http://www.ketotic.org/2012/08/if-you-eat-excess-protein-does-it-turn.html, http://ajcn.nutrition.org/content/86/2/276.full, and http://omega3galil.com/web/8888/nsf/web/5922/148534imagefile3.pdf
Gluconeogenesis in diabetes: "The rate of gluconeogenesis was three times higher in the diabetic subjects than in the control subjects" http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995498/
|"So long as your body has retained any level of glycogen (the liver usually is about 40% glycogen, plus some is stored in muscles) you will not tear apart proteins for glucose"||So how is the body keeping glycogen level from being completely depleted after years and years? Gluconeogenesis, aka making glucose from proteins, see above point.|
We never stop using glucose completely even when fully keto-adapted, parts of the body always need glucose, this is why blood sugar levels are maintained at a stable level even when no carbohydrates are eaten, and why we have a way of making glucose from protein. If you give a drug to reduce blood sugar down too low, we would soon faint and then die. Glucose is vital for life, the question is whether it's better to eat it or make it ourselves (this is of course a topic for another day but the above links discussing the rate of gluconeogenesis on a high/low carb diet points very heavily to it being making it ourselves).
|"If the body was able to create glucose on demand from ripping the core out of protein, then why is 100% protein so deadly it can kill you in about a week to ten days? Adding dietary fat or carbs prevents this poisoning. The fact is gluconeogenesis is rare except under two conditions, severe fasting and recovery from starvation-induced bodyfat depletion on a zero carb diet. Then the adipose tissues are re-built by diverting a small amount of blood sugar which stimulates mild gluconeogenesis."||Protein toxicity, or rabbit starvation, is when too much protein is eaten. The toxicity is not from the protein itself but the breakdown products of the protein which accumulate faster than they can be removed from the body. Stefansson experienced this after only too days on a high-protein low-fat carnivore diet.|
The last bits makes no sense at all. Adipose (fat cells) would be rebuilt from dietary fat. After every meal the fat you eat is stored in your fat cells (but they can freely leave to supply fuel/energy between meals and overnight as insulin is kept low all the time), too much fat in the blood is also harmful to the body just like too high blood sugar. Blood sugar doesn't stimulate gluconeogenesis, a lack of it does (as in low blood sugar stimulates gluconeogenesis in order to raise blood sugar to a safe level).
The idea that fat tissue, an active regulatory tissue in the body, is simply destroyed and rebuilt on demand is fallacy. This is easily verified in any medical text book since the invention of the microscope.
Also this point is a void anyway, any diet made of 100% of just one nutrient would be fatal, not just protein.
|"Glycogen is not depleted by exercise, period. The muscles ONLY use free fatty acids complexed with n-acetylcarnitine to provide the energy to reverse ADP to ATP, no carbs are consumed in this process, either as glucose or as glycogen.|
The famous 'wall' hit by runners etc., indicates a problem in mobilising bodyfat in a carb-loading individual once dietary circulating fat is consumed. It does not occur in a keto-adapted meat eater."
|Glycogen is depleted in exercise, though when keto-adapted it is used up at a much slower speed and can be refilled by gluconeogenesis easily such that it never appears to decrease. Glucose is used to generate ATP, it enters the Krebs cycle via pyruvate.|
The 'wall' is caused by depleted glycogen and has been studied extensively, but he's quite right that that you also need an ability to access your fat stores too. The winner of the last Western States 100, a 100 mile ultra-marathon, was described as low-carb but when actually questioned as to what he ate while running it was revealed that he was some carbs to refill glycogen albeit a fraction compared to the high-carb runners.
Exercise when keto-adapted meaning being able to burn both glycogen/glucose and fats/ketones for fuel at the same time.
Anaerobic exercise always uses glycose/glycogen for fuel, as without oxygen fat/ketones can't be oxidised, the glucose/glycogen is metabolised to lactate aka lactic acid, which will build up in the muscle until the exercise is reduced enough or stopped such that oxygen can being used to metabolise the lactate back into glucose.
In a way the whole animal versus just fatty muscle meat argument could be boiled down to a these comparisons:
|ZC community||Weston A Price|
|Based on one group, the Inuit; and the experience of a few people, mostly theBear||Travelled the globe looking at many different cultures and what that had in common|
|Based on conjecture, no real scientific basis for only fatty muscle meat||All cultures went to great lengths to ensure supply of foods which contained the fat soluble vitamins A, D, and K2, animal protein, and the long chain omega-3 fatty acids EPA and DHA|
|Says no harm with come to you eating nothing but fatty meat||Photographed results of fat soluble vitamins deficiencies, such as lack of eyes in pigs born to vitamin A deficient mothers|
|"If it's not in fatty meat, then you don't need it"||Actually tested the foods different people ate to see what nutrients they were getting and from where they got them|
|Based on the experience of a few decades at most, by a handful of people||Based on the accumulated knowledge of many thousands of years of knowledge by people from all over the world|
|theBear: no scientific background, frequently gets things wrong||Accomplished scientist who was knowledgeable far beyond his time|
If organs (or other animal foods like egg/dairy) aren't needed and just fatty muscle meat is not only sufficient but actually optimal, then why do other carnivorous animals get very sick on just fatty muscle meat, why did primitive cultures put so much importance on organs and other sacred foods even sometimes going to extreme lengths to obtain them.
In nature, the predators who eat first (the alpha wolves, the lion) will go for the abdominal cavity, and organs at once and even fight to defend their choice cuts. Betas will eat the peripheral organs and muscle meat, both will eat fat. Bones will be broken and contents eaten by all. As well scavengers quite often will work the smaller bones the top level predators missed, as well as eat things like the eyes (carnivorous birds especially). The whole animal in nature is essentially picked clean of anything edible by a series of carnivores.
The simple truth is there has never been any carnivorous animal of meat-eating human population who didn't eat the whole animal until very recently. Practically everyone even included a serving of liver a week until the last few decades or so.
Is there some magical difference between modern day zero carbers and every single other carnivorous animal and every single primitive culture? Because unless there is some magical difference then eating a diet of purely fatty muscle meat is highly dangerous? Are zero carbers that arrogant in the status or 'truthiness' of their leaders' a priori proclamations that they are willing to risk serious deficiencies will possibly permanent damage? How arrogant do you have to be to do that?!
In my mind these people are no better than fruitarians who also claim their diet is perfect, that any nutrient not found in fruit/veg is not needed (replace fruit/veg with steak), etc. In fact just go to the table above and replace every instance of 'fatty muscle meat' with 'fruit/veg' and you'll have 90% of what comes out of a fruitarian's ass.
At least the fruitarians have admitted that you need vitamin B12 injections on their diet after people have gotten permanent nerve damage or had their babies die from B12 deficiencies. How long do we have to wait for ZCers or their unfortunate children to go blind from retinol deficiency or even die, before they realise the stupidity of ignoring that fact that certain substances are vital for health, or even just life itself?!
Do you really want to be part of an experiment of which the results are at best unknown and at worst extremely dangerous? No... Then eat your liver and drink your gelatin-rich bone broth, or eat eggs, dairy, or other animal foods.
If you follow a zero carb diet which includes eggs or dairy, but think I'm wrong, don't complain to me, this is about people eating only fatty muscle and no other food, your diet includes nutrients not found in muscle meat so your lack of deficiency doesn't prove just muscle meat is healthy.
|Main nutrients low in a|
muscle meat only diet
|Retinol||Cod liver oil, liver, egg yolks, dairy|
|Folate||Poultry Liver, less so mammal liver|
|Choline||Egg yolks, liver|
|Calcium||Bone broth, bones in fish, egg shells|
|Magnesium||Soils are depleted so supplements advised|
|Glycine & proline||Gelatin (skin, feet/hooves, cartilage, heads,|
tails, ears, powder/sheets)
I am still looking at how much of each nutrient is needed on a ketogenic carnivore/near-carnivore diet, but the result is highly likely to still include liver, gelatin, bone broth (or other calcium sources), and possibly other organs, eggs, and other animal foods; NOT just muscle meat.