TPNS 58-61: Ketosis Is Natural. Natural Is Good.
Monday, March 26, 2012 at 02:20PM
Plant Positive

Primitive Nutrition 58:
Ketosis Is Natural. Natural Is Good. Part I


So far in my examination of low-carb diets I've shown you that they are nutritionally deficient, metabolically damaging, and unlikely to produce weight loss, if only because fats are so calorically dense.  For the low-carbers, the solution to this last problem is ketosis.  For them, this special metabolic state is the ultimate goal of their diets.  They imagine it will effortlessly melt away all the fat they've accumulated from their prior unhealthy eating behavior.

Low carbers' zeal for ketosis has lead some to make a questionable claim which I'd like to ponder in this section.  Michael Eades presents it here in his blog explaining ketosis.  Of course, like many other primitive fad diet promoters, he wants you to start from the assumption that the activity pictured to the left somehow represents man's true nature and the way he has historically obtained food.  I don't see any women in that photo, which should give you a clue that this isn't the whole story.

According to The Economist, among the hunter gatherers who provide the Paleo model, "men usually bring fewer calories than women, and have a tiresome tendency to prefer catching big and infrequent prey so they can show off."  Eades is tapping into the same old macho vanity that has worked so well in marketing Paleo.

If you'd like to see what a group spear hunt really looks like in live action, watch this video.  Somehow the artist who created Dr Eades picture forgot to include all the blood.  Having read a bit about how intelligent and social elephants are, I find this unappealing to say the least.  If you watch it, see if you can imagine Michael Eades participating in such a hunt. 

But back to ketosis, despite his acknowledgement that ketogenic diets create a state quite a lot like starvation, he considers ketosis to be the normal human metabolism.  This seems to me to be a bizarre opinion, but he isn't the only one who says this.

This is a man with a proper education in nutrition who believes ketosis is the preferred human metabolic state.  He has a site called  He wants you in full gloom, avoiding sweetness in general and even limiting vegetables.  How can someone come to believe this?  Is ketosis natural?  Of course it it, just like starvation and death are natural.  But is it healthy, normal and desirable?  That is the subject of this section.

If you don't understand what a ketogenic diet is, I suggest you pause the video and read through this short description.  Ketogenic diets are designed to deprive the body of the carbs it needs for normal metabolism.  The diet has to be extreme to break the normal mechanism your body uses to burn fuel and to induce a dramatic elevation in the number of ketone bodies present in your bloodstream.

One of these ketone bodies is acetone, so someone in ketosis has breath that smells like nail polish remover.

These ketone bodies are acidic, which is why when you read the research conducted by the low carb gurus they supplement with sodium and other minerals.  Without this addition, the blood may become dangerously acidic.

I don't know of any other diets that require broths.  Low carbers try to make a virtue of this but it is clear this is only to minimize the adverse consequences of such an extreme diet.

The Atkins website runs down the problems attendant to this distorted diet without their supplementation ritual.

These diets are seen as mimicking the effects of starvation.

Ketogenic diets are used therapeutically today to control the seizures of epileptic children.  They have been used this way for many decades.  Fasting had long been known to be an effective method of seizure control.  In the 1920s a doctor named Wilder recognized how metabolically similar a ketogenic diet was to fasting.

It was this similarity that gave him the idea to use this extreme diet as a tool for managing seizures. 

It is not clear whether it is the reduction in blood sugar or the ketone bodies themselves that reduce seizures.

It is from observations of children subjected to such diets that most of the effects of the long term use of these diets are understood.  Here, for example, we see that these diets are damaging to the bones of these children.  This is only one hazard of this supposedly natural and normal diet.

Imagine little children having high cholesterol or kidney stones.  That doesn't sound natural to me.

Here is a list of the potential problems kids on these diets face.  I think if a similar list could be compiled for vegan diets the low carbers would find it quite damning, but somehow they still like ketogenic diets.

Despite the potential these diets offer for the treatment of epileptics, these numerous health hazards have hampered research into them.

If ketogenic diets are so natural and good, why do children abandon them at the earliest opportunity?  Why do they not prefer high-fat foods when they are back on normal diets?  Are these kids resisting their basic nature for some reason?  Are they under the spell of Ancel Keys, too?

Eades acknowledges the similarity between ketogenic diets and starvation, but starvation is not the only circumstance in which ketosis takes place.  Ketosis also takes place during uncontrolled diabetes and chronic alcoholism. 

Also producing ketosis are anorexia nervosa, prolonged vomiting, and several gastrointestinal diseases.  Of course, these all are unique in their own ways, but these associations should provoke a little skepticism of these diets.

As I said, the number of ketone bodies in the blood is dramatically escalated in ketosis, which are otherwise kept at very low levels by the intelligent systems of your body.  You know you're in ketosis when you have ketone bodies in your urine.

This is why low carbers buy a product called ketostix.  Diabetics use these to test their urine for ketone bodies.  If they have them in their urine, it means their insulin is too low and blood sugar too high, and this is a serious problem.  But for fad dieters, they want these ketone bodies in their urine.  This brings up another question for those who think ketosis is so normal.  Why should a person need to test their urine to see if they are in the preferred metabolic state?  Shouldn't it be easy to keep your body in ketosis if it's preferable?

Ketosis is rather delicate, actually.  Even sugar alcohols and the fillers in artificial sweeteners can provide enough carbs to knock you out of ketosis.  Why should the body be so resistant to it's preferred state?

There are a lot of things you can eat that will stop this supposedly preferred metabolic state, including most amino acids and even the fraction of fats which can be turned into glucose in humans.

Eades also wants you to believe ketosis is somehow efficient for your organs. He says the heart is 28 percent more efficient when it is fueled by ketones.  He says this even as he admits that glucose is still required by the brain.  I think it makes some sense that under conditions of starvation, it might be good for the heart to operate more efficiently.  Does this mean the rest of the organs operate more efficiently on ketones, too?  Is he saying this was a metabolic adaptation originating specifically in man during the Paleolithic?  Look for the answers to these questions and you'll see just how far off Eades' Paleologic is.

We're going to get back to basics in Part II.


Primitive Nutrition 59:
Ketosis Is Natural. Natural Is Good. Part II


Michael Eades says the heart runs more efficiently when fueled by ketone bodies.  So then ketosis makes your other organs, and indeed your whole body, more efficient, right?

To answer this, let's first look at the issue of efficiency generally before we look at specific organs.  Ketosis is the result of the breakdown of the normal cycle of chemical reactions most organisms, including us, use to convert nutrients into energy.  Your body needs some carbohydrate for this set of reactions, called the Krebs cycle, in order to extract all the energy available from fatty acids.

This is why it is often said that fat burns on the flame of carbohydrate.  Ketosis, therefore, is inherently inefficient.  Not only is less energy extracted from fat than normal, the energy available in excess ketone bodies is wasted in the urine.

Ketone bodies themselves are low in energy.  ATP is the elemental source of energy for all processes in your body.  Glucose produces 36 ATP.  Calorie-dense fat produces 146 ATP.  Ketone bodies, however, only yield 22 ATP.  This demonstrates the slouching approach to health of the low carbers at the most fundamental level.  Do they think we have evolved to store energy so well only to later waste it?  What do they think the purpose of body fat is?

Fat is there to provide energy to make survival possible in times of food scarcity.  A man carrying an extra 30 lbs of fat has a whopping 130,000 calories to burn when food is unavailable.  Think of this in terms of evolution and I hope you'll agree it's quite amazing that our bodies can do this so well.  We've evolved to be efficient machines, and this is one example of that. 

Consider that even without ketosis, fat metabolism is less efficient than carbohydrate metabolism because it requires more oxygen.    Moreover, it is hardly efficient to carry around a bunch of fat you don't need all the time. 

Fat is also less versatile than carbs.  Your body can turn glucose into fat, but it can't convert most fat into glucose. 

Lastly, ketosis wastes a lot of water, which can hardly be called efficient.  Looked at from the perspective of efficiency, fat is clearly a fallback fuel for use in hard times. Your body uses carbs much more efficiently.  Yet your body stores fat because it is just so good at keeping you from dying of starvation.  And that is because it holds lots of calories.  It would not have provided your ancestors any advantage to waste those calories.  So why say ketosis is natural?

Glucose is clearly the preferred energy source.  All human cells can use it.  Does that seem to be an overly broad statement?

We can take it further.  Glucose is the principal energy source for all living cells.  Can Michael Eades say the same about ketone bodies?

Remember Eades' statement that ketones are the preferred energy source for the heart?  What about the rest of your body?

Well, he said that ketones can't totally replace glucose as a fuel for the brain.  He should have said that except under extreme conditions glucose is nearly the only source. 

Your brain actually uses glucose disproportionately to the rest of your body, burning 25% of your glucose.

Our brains' greediness for glucose is far beyond what is seen in all other mammals.

Your brain only uses ketone bodies as a back-up power source. It has no minimum requirement for them.  They can even cause your brain to work less efficiently.

What about your muscles?  They're an interesting case.  Your muscles store carbs in the form of glycogen.  Your muscles are so stingy with glycogen, they won't share it with the rest of your body.

They keep their glycogen separate from your blood glucose regulation system.

If you engage in exercise and thereby become a more efficient machine, your muscles become better at storing glycogen to fuel them. Ketosis, on the other hand, requires the depletion of glycogen from the body.  This raises a question for those who think your body prefers ketosis.  Are they saying that as you become more physically fit and strong, you are also becoming increasingly metabolically broken? 

At this point you know that ketogenic diets are not adequate for athletes.  This is reason enough to conclude ketosis is not the preferred metabolic state.

So we know that your brain and muscles prefer glucose rather than ketone bodies from fatty acids.  Let's add to that list your red blood cells, which cannot use ketone bodies or fatty acids at all.  Without glucose they'll die, and without red blood cells, you’ll die.

Let's reconsider the heart while we're looking at different organs.  During normal metabolism your heart does not prefer ketone bodies.  Instead, it uses fatty acids.  Eades doesn't mention this.

In pondering Eades' statement that carb restriction was the norm for most of our existence as upright walking beings, with starvation being the normal metabolism, I find myself asking lots of questions.  Homo developed big, energy-expensive brains on a starvation metabolism?  Why would we hyper develop this uniquely glucose dependent organ in a glucose-poor environment?

Why do we seem so uniquely adapted to consuming starch?

I got to wondering, since it seems so improbable that ketosis is the normal metabolism for us, could it be the normal metabolism for any animals?  After all, Eades wants us to essentially be carnivores.  So are carnivores normally in a state of ketosis?

The answer is in Part III.

Primitive Nutrition 60:
Ketosis Is Natural. Natural Is Good. Part III


At the end of Part II I was wondering if any animals at all stay in ketosis under normal conditions.  It seems to me that carnivores are the world’s top low carbers so let's investigate them first.

Carnivores don't have much use for dietary glucose.  They are so dependent on animal protein they can't synthesize some amino acids the way we can.  So they must be in ketosis then, right?

Nope.  Carnivores need glucose.  They just make their glucose from the protein they consume.

Therefore, they consume protein not to satisfy an especially high protein requirement so much as they consume extra protein to satisfy their requirement for carbs, which are made during gluconeogenesis.

Here you see our minimum protein requirement is put in the range of 6 to 8% of calories.  Cats need at least 14 to 20%, yet their protein turnover is actually slower than in other mammals.  The extra protein is for making glucose.  Therefore, cats on low carb diets cannot enter ketosis if given adequate protein.  If a cat is in ketosis, it's either because it's diabetic or in prolonged starvation.

A protein-based diet enables cats to supply a steady stream of glucose to their tissues.

It's a good thing for them this glucose is supplied so steadily.  They have insignificant liver glycogen reserves to supply glucose in between meals.

This is why a carnivore like the mink is so poorly adapted to food deprivation.  It is quickly forced to break down its own body proteins to produce glucose.

What about that most low-carb, high-fat of carnivores, the polar bear.  Surely they are the one species that is normally in ketosis.  After all, they show a greater preference for fat than protein.  Could they really be running more on glucose than ketone bodies on such a fatty diet?

Polar bears are unique, but not because they are in ketosis.  They are actually using all that fat to manage their body water.  Because it can be hard to get enough water to drink in the Arctic, they don't want to eat excess protein because, as you will recall from my Protein Choices videos, the digestion of excess protein requires lots of extra water to eliminate all that urea.

When polar bears are starving, they actually begin to produce more glucose.  Unlike other mammals, they resist ketosis even during a fast.  They seem to be capable of turning their fat into glucose, something we can't do to a significant degree.

Notice the paragraph to the left.  If we look at ketosis as the back-up metabolism after normal carbohydrate metabolism breaks down, what is the back-up to ketosis?  There isn't one.  Even during terminal starvation, their bodies will make glucose right up until the end.

Polar bears in captivity are not fed a diet like they would consume in the wild.  They are actually fed fruits and vegetables.  But this isn’t their natural diet!  Surely this is a form of animal abuse, right?

Actually, polar bears in captivity live considerably longer.  But shouldn't an evolutionarily novel diet destroy their health?  This is yet another example of how Paleologic is no substitute for experiment and observation.

If there ever were an observed human culture that normally experienced ketosis, it would have to be the Eskimos.  They have eaten as close to an all-animal-flesh, polar-bear-like diet as any humans ever have.  Perhaps they will be an example of Dr Eades' normal metabolism.  Knowing now that polar bears are so resistant to ketosis, you might be doubtful, of this.  Your doubt is justified.  Eskimos don't normally develop ketosis.

This was studied all the way back in 1928.  Eskimos showed no ketosis at all on their traditional diet and during starvation became only mildly ketotic.

Even after his famous year-long meat diet experiment, everyone's favorite low-carber Vilhjalmur Stefansson did not experience ketosis.  His gluconeogenesis cranked up to make up for his carb deficiency.

Explorers who encountered Eskimos nearly 100 years ago remarked that they ate outrageous amounts of meat.  20 pounds of meat in a day!  Low carb didn't promote satiety for the Eskimos, did it?

Eskimos ate all that meat to turn their protein into glucose, which sounds like what carnivores do.  Eskimos were known to have unusually large livers, and this was speculated to be due to an adaptation to create more glucose from protein than other humans.

All that glucose probably kept them warm.  The present day practice of consuming sugar to stay warm goes back a long way.  Here in 1915 explorers in the Antarctic found sugar to be a necessity to tolerate the cold. 

Sugary beverages are advised for use today to warm up hypothermia victims.  Sugar would have been useful in any cold ice age landscape Dr Eades might be imagining, even if it was produced from protein.

Evolution helps us look at this from another angle.  An understanding of the utility of high levels of blood glucose in extreme cold has lead this doctor to suggest Type 1 diabetes is the result of an adaptation to cold.  Extra glucose would have prevented the formation of ice crystals in the blood.

In fact, Type 1 diabetes does have a pattern of occurrence that links it to cold weather.  Evolution seems to say that cold weather requires more glucose in humans and other animals, not less.

It seems to me this is the fatal flaw of the rationale for ketogenic diets that cheerleaders like Stephen Phinney like to employ.  The cold weather adaptation argument is not only ahistorical, it is metabolically backwards.

What about ketosis in naturally high-carb-eating mammals?  What can we learn about ketogenic diets from them?  That's where I start in Part IV.


Primitive Nutrition 61:
Ketosis Is Natural. Natural Is Good. Part IV


Let's look at ketosis in mammals at the other end of the carb spectrum.  If Eades says our normal metabolism is ketosis, and if ketosis is the result of carbohydrate restriction, then our primate relatives, which are frugivores who do not restrict their carbs, must then be resistant to ketosis by this logic.  In other words, in Eades’ mind we are natural ketotic low carbers, so ketosis must be really unnatural for primates because they eat so many carbs.  But this is not the case.  Primates experience ketosis a lot like us.

In the context of other species, even though we don’t enter or stay in ketosis easily, we are still on the end of the spectrum of animals that more easily enter ketosis right along with fruit-eating monkeys.  On the other end of the spectrum are dogs, which have much more obvious adaptations to meat eating such as teeth built for tearing rather than grinding. Dogs resist ketosis.  Farther still along this continuum would be polar bears.  Considering ketosis in other species, it seems very unlikely that we would normally be ketotic low carbers.

We're like primates in another way that wrecks the ketosis-is-normal argument.  You probably also know there are awful consequences to not consuming adequate vitamin C, namely scurvy.  Not only are we next to fruit-eating primates in the area of ketosis, we are next to them with our need for vitamin C as well.  Most mammals can synthesize their own vitamin C but primates like us can't.

A very good hypothesis to explain this is that we, like the other primates, consumed vitamin C from fruit regularly enough that our pre-homo ancestors did not need the ability to synthesize it. This created what amounts to a nutritional addiction.  We need to get our vitamin C fix somehow.

Here's another evolution-based argument for carbs and fruit.  It is also believed that our color perception developed from our ancestors' fruit-based diet.  Advanced color vision helped them to be discerning fruit-eaters.

Low carbers may say that Eskimos received enough vitamin C to prevent scurvy in the uncooked animal tissues they ate.  Cooking these meats would destroy that vitamin C, though, and we know that cooking goes back minimally around 400,000 years, which includes periods that were warmer than today.  This is before the beginnings of anatomically modern humans.  This timeline argues against the idea that our vitamin C requirement originated with the eating of uncooked meat.  The consumption of plenty of vitamin C from fruit long before that makes a lot more sense as an explanation.

I've noticed that low carb apologist and cholesterol denier Uffe Ravnskov thinks we need higher amounts of vitamin C than what is currently recommended by most institutions.  Just enough to prevent scurvy isn’t good enough for him.

I can't say I disagree.  I just wonder how he and Michael Eades would see us getting high levels of vitamin C on a natural low carb, ketogenic diet...

Especially during the times in our history when our ancestors lived in warm climates.  Here is a text from 1900 written by a US Army surgeon who noted that inhabitants of hot climates found meats and fats distasteful, preferring mostly vegetarian food.  Is Eades saying that it is more natural for humans to live in areas that are brutally cold?  Where does he think most people live?

It seems the human species concentrates more in warm places rather than cold places.

From an evolutionary perspective, it's clear the basic problem with Eades' thinking is that the capability to enter ketosis is not a uniquely human capability.  It seems almost all mammals can do it to some extent, regardless of their natural diet.  Therefore, ketosis metabolism must pre-date the first humans.

I would suggest another proof that ketosis is not normal is the issue of pregnancy, yet the guy goes there in this blog.  Without coming out and saying it directly, he tries to give the impression by presenting a handful of animal studies that ketogenic diets are appropriate for pregnancy.  This man is advising women to eat a lot of saturated fat and keep carbs low during pregnancy. 

This is quite irresponsible.  Even Eades, while he says ketosis is the normal human state, won't condone this fanaticism.  I'm not sure how he reconciles his belief in the normalcy of ketosis with how damaging ketosis is to a fetus, but at least he draws a line somewhere.

This guy, though, sarcastically mocks the lack of human studies of low carb diets during pregnancy.  The studies he does cite don't help him make his case very well.  The first is about glycemic load which is a non sequitur here.

He doesn't tell us he's referring to a study using a product called the "Solo GI Bar." The manufacturer of these snack bars supplied the researchers with all the bars they needed.  The other low-GI foods in the study were whole grains, fruits, vegetables, nuts and legumes.  Does he really think these researchers would approve of using this paper to promote ketogenic diets during pregnancy?  That’s quite a stretch!

He says the second study he references tells us pregnant women do better with carbs kept down to 40 to 45% of calories.

He neglects to mention the women in the study had diabetes, which seems an important detail to leave out.  Their carbohydrate metabolism was already broken.  Do you see why I am showing you all these studies?  I need you to see how trustworthy these people are.

Here are some facts the guy won't tell you.  Ketone bodies are likely to induce birth defects.

This is why groups assisting women to have successful pregnancies want them to test their urine.  They want them to make sure they aren't in ketosis.

For a while Robert Atkins himself recommended his awful diet to pregnant women.

He eventually learned that his diet could damage a fetus.  He then changed his mind.

If we are talking pregnancy, once again, we can look for clues in evolution that show us what proper nutrition looks like.  Fruit-eating primates start to become ketotic during times of fruit scarcity.  Females vary their fertility so that they are more likely to conceive when there is plenty of fruit around.

We don't have to consider evolution to know that ketosis is not desirable, though.  As I stated earlier, we know that children suffer ill-effects from these diets, including slowed growth, kidney stones and fractures.

We also have animal studies that show they can derange metabolism toward more accumulation of visceral fat.

And that they interfere with the hormones insulin and leptin.

Ketogenic diets also produce some of the very worst known risk factors for heart disease, which correlate with the degree of ketosis.

Top obesity researchers have found ketogenic diets have no benefit over other weight-loss diets.  To the extent they seem to work, it is believed this is simply due to the lower caloric intake most people consume on them.  Here's one reference for that.

And here's another.

Comparing a ketogenic diet to a less extreme low-carb diet, the ketogenic diet is not better for weight loss.  A ketogenic diet is, however, worse for cholesterol, inflammation, and emotional well-being.

And low-carb diets themselves are hard on emotional well-being.

Put it all together and you can see why a fad diet promoter needs to appeal to your inner disordered eater with language like this.  "On a low-carb diet you can feast and starve all at the same time."  This is the lazy, confused, magical thinking of low-carb in a single sentence.  Gullible diet chasers desperate for a quick and easy fix at any long-term cost, exit here.  All others proceed to a sustainable and healthy approach based on whole plant foods.

I have plenty more of Michael Eades in the next section of the Primitive Nutrition Series.  What can we learn from diet in China?  And just how ridiculous can Michael Eades get?  This may give you a headache, folks.  You have been warned.

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