I watch those documentaries on existing hunter gatherer tribes today. I read a lot of the existing studies on traditional hunter gatherer diets. I ascertain that 1) They eat nose to tail and 2) They eat from 4 main food groups that contain calories (meat, nuts/seeds, roots, fruits/berries, and honey). The standard ketogenic diet calls for at least 60% of calories from fat, and under 10% of calories from carbs.
Major sources of protein are from wild pigs, monkeys, small birds, eggs (very seasonal), small Gazelle type creatures, Antelope, and reptiles. The largest mammal I am aware of them eating (and not even nearly on a daily basis) is Antelope, which is quite lean. Even the fat humans are only about 20-30% body fat. So you wouldn't even be able to make it into ketosis if you lived on fat American's. Why would you be able to make it into ketosis regularly when you aren't eating fat animals or animals any where near 60% fat and don't intentionally exclude other sources of calories? Butter and oils are not consumed in traditional hunter gatherer societies. If we can omit the outlier that is the Inuit, it seems to me that it would be extraordinarily hard to eat a ketogenic diet as a hunter gatherer...even as a hunter gatherer who is TRYING to live in ketosis, because meat doesn't even get close to being 60% fat.
In short. Ketosis via a high fat diet is a Neolithic phenomenon, is it not? Of course, our ancestors may very likely have dipped into ketosis from calorie restriction, but not from a high fat diet. high fat ketosis = Neolithic. Intermittent calorie restriction ketosis = paleolithic.
I am not even going to touch on gluconeogenesis from protein, which would make it even harder to get into ketosis if you eat nose to tail.
Is this totally incorrect reasoning? It very well could be. IF it is, could you please correct me?
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I think the disconnect is assuming that Paleo peoples were ketogenic. I'm pretty sure they stayed lean by earning their food on a different level than we do today.
Likewise, if anybody knows better...
It has nothing to do with the vast majority of HG societies ever observed. I think maybe they're imagining themselves hunting mastodon on a tundra during the last glacial maximum or something along those lines. I doubt that even the neanderthals were actually anything close to obligate carnivores.
During our entire evolution there were the smart ones back near the equator eating a highly varied diet (the Hadza are known to eat 880 different species - 741 of which are birds, to be fair). There can be massive sex differences in diet just among a single group. During a period of a year, the Hadza men were observed eating about 40% meat, while the women ate less than 2% meat (in camp). We are a highly adaptable species that can live off of a great number of things.
I've read that their hunting failure rate is 97%, even with bows, steel arrowheads and several types of poison (so just imagine a neanderthal with a relatively crude spear). They simply cannot eat meat every day. Most of the time they're going to be eating their fallback foods like tubers and baobab
Anyway, I think the people who eat these diets must be doing so as a means to treat a particular health issue, not because the think it's something their ancestors did.
"meat doesn't get close to 60% fat" I'm not sure about that if we're talking hunter-gatherers. From what I understand many cultures have preferred to consume the fatty parts (organs and tounges) and consider the muscle meat to be lower quality or less tasty, so its fed to the dogs.
I'm pretty sure the standard Ketosis diet was created in or around 1921 as a therapy. They were trying to mimic the effects of fasting so that sick people could benefit from fasting without, well, dying from not having enough food. Elizabeth A Thiele did an AHS talk on this.
In terms of what happened in the paleolithic- people went into ketosis when there were periods of time when they fasted (our own fat stores do get converted into ketones) and/or during times when they did get a sufficiently fatty animal, but no carbs. So people moved in and out of ketosis depending on the food situation in the area. No one would be trying to stay in ketosis- they would be trying to get out of it.
It has value as a therapy and a similar value as fasting for paleo practitioners wanting to maintain adaptability.
Probably only relevant to the discussion in the comments, but I don't like them to be hidden down there.
Well, since we actively sought out fat, we ate the same foods as lions on the savanna, and unless it's the dry season animals are still quite fatty, IMO dietary ketosis was a possibility. Did we actually do it? I'm not sure, it's next to impossible to tell.
14:55 min mark: http://www.youtube.com/watch?v=OrjM47L_hnE&feature=youtu.be I really enjoyed this documentary.
If we did do it, did they say dumb shit like "your not doing it right!" or "hey Frank I saw you eat that tuber this morning, your gonna get the low carb flu again!"
No argument about how or when some mythical paleo person entered ketosis (obviously though it's a preserved physiological capability, so it probably helped during some evolutionary bottleneck). But, afaik, the "60%" number you are throwing out to enter ketosis isn't a hard and fast number, and it's also referring to energy not mass. So if you had 60% of your energy intake from fat it wouldn't require an animal that had any more than 25% body fat, really, in fact it could have 10% body fat, by mass, and you could still get 60% of YOUR energy from eating that fat.
Well you know alot more about paleo diets than me, but one thing I do know that may solve your conundrum is that a diet 60% fat by calories is only 30% fat by weight. Remember that fat has double the energy (calories) compared to an equal weight of either carbs or protein. ie double the energy density.
So if you eat a fat American (or a fat Australian like me) who is 30% fat by weight, then thats roughly 60% of your calories coming from fat.
I calculated I could live for 3 months just consuming my own 35 kg (77 lbs) of fat and nothing else, thats assuming the following: normal dehydrated weight of bushwalking food is about 650 g per active day; if that was all fat you would need a little over half that, say 350 g fat per active day So that should last 100 days; just over 3 months.
Link for more detail http://www.caloriesperhour.com/tutorial_pound.php
Just thought I'd add that producing ketones is not dependent on carb intake. If you flood your liver with the right fats you'll produce them in quantity.
An excerpt:That answer maybe buried in the bio-energenic literature I reviewed while a resident at LSU for brain energy transport. I recalled reading about the effects of the ketogenic diet on pediatric brain tumor patients and on patients with neurodegenerative disorders in the mid 1990s. I had to put together a talk on this back in 1995. When I got home I opened up some books and Pubmed searched a bit. I think that nap might have been what I have been looking for. Got to love autophagy from sleep! It surely does stimulate neurogenesis so we can learn!
First, let???s talk a little bit about what a ketogenic diet is and what it does for certain peoples??? brains. It is a current mainstream treatment for epilepsy and neurosurgical pathology today but it is rarely used often enough. The reason it is not used is because antiepileptic drugs are now considered first lines of therapy these days. Conventional medicine wisdom exists even in neurology and neurosurgery I am afraid. The treatment actually dates back to the early Greek civilization around 350-400 BC. They used fasting as a way to improve the symptoms of epilepsy. I remember reading back then the reason the treatment often failed is because the patients got quite hungry after a week of this. So it was not a sustainable long term treatment. The medical community re-discovered fasting at the turn of the 20th century in Europe. A study was even undertaken in France to show its efficacy. It showed much promise but again compliance was the rate limiting factor. The idea then traveled across the pond to the USA and several physicians came up with a ???modified water diet??? that had ten percent food and 90% water as its backbone. The American trials showed promise but again were limited by hunger compliance.
Interestingly enough, one of the patients was boy who father was a rich NYC landlord who donated some money for further research into how this ???water diet??? actually worked. The money went to Dr. Lennox and Dr. Cobb at Johns Hopkins, who later became famous. From those studies we found out that fasting induced the formation of ketone bodies. All three ketone bodies were found with that grant. Once this occurred the Mayo Clinic researchers joined the party and actually named the diet the ???ketogenic diet???. They actually worked out the macronutrient ratios for the diet to be used in 1924. They found children needed one gram of protein per KG of weight, no more than 15 grams of carbohydrates per day, and the rest of dietary calories had to come from fat. Once this was done it was used extensively in children with great success. It met with limited success in adults and interestingly enough, this is why the diet was abandoned and antiepileptic medications became first line drugs back then. This is where my residency recall ended of the papers I had read for my talk. I knew even today that in difficult seizure cases where all medications fail, like Lennox-Gastaut syndrome, that the ketogenic diet is still used. I have used it myself as a neurosurgeon for patients with difficult seizure control who harbor brain tumors.
The diet came back to life while I was in residency because another famous NY TV person had a son who went on the diet and did quite well. They even made a TV show about the child???s case. A multicenter trial was begun and the results released as I was finishing my training in Neurosurgery. Today most epilepsy centers offer ketogenic diets as mainstream therapy for drug resistant seizure disorders. It is even covered by all US insurance carriers as of 2011. Interestingly, the literature is bare with a mechanism of action. I can hear you saying this to me now, Doc, where is this all heading? Why should I care? Well, in the paleo blogosphere there are so many arguments about macro and micronutirents ratios and levels and what is optimal and what is not. There are constant questions to many podcasters asking about metabolic typing and related topics. I think the ketogenic diet firmly answers the question whether or not specific macronutrient levels can have a direct effect on metabolism in a measurable way. Remember most current low carb paleo diets are direct ketogenic diets as well. Here comes your relevance.
The ketogenic diet of today is loaded with MCTs usually from coconut oil. MCT are metabolized quite differently than other fats. The low carb paleo diet is heavily steeped in MCT oils as well. The carb content is usually kept below 100 grams but the range most use is even lower than that. Mind you I don???t advocate this across the board for everyone.
I myself eat a high percentage of calories of fat and protein with copius amounts of non fluoridated hard water based upon my own testing and results. This puts the patient in sustained ketosis and is a successful way to reverse metabolic syndrome and lose weight. But it confers a much bigger advantage that previously has gone unrecognized until now. What is that advantage? OK??????.this part is going to hurt your brain because it has a lot of cerebral physiology but I promise the pay off is worth it.
In neurosurgery, we have hundreds of thousands of studies done on the coupling of cerebral blood flow (CBF) to cerebral metabolic rate of oxygen consumption (CMRO2). Neurosurgeons are experts in managing CBF and CMRO2 in neurologic injury or in pathologic states to navigate patients back to health. We spent seven years learning how to alter this simple equation to provide the best outcomes to patients. We need to control CBF often because, if it increases indiscriminately, the patient will die because the brain swells and it is located in a fixed closed compartment. This is commonly how one becomes brain dead in case you are wondering. The brain controls its own CBF by a process called autoregulation. In simple terms, the metabolic activity of the neurons determines how much blood flow a certain region of the brain gets. The only way to uncouple CBF from metabolism and keeping the patient alive is inducing general anesthesia. Uncoupling or losing autoregulatory control does occur in many neurologic diseases. For example , when we do dynamic cerebral blood flow studies in the brain we can tell the difference between patients with Alzheimer???s disease (AD) and vascular dementia by testing their metabolic consumption of oxygen. The difference lies in how the CBF looks in each disease.
In vascular dementia (chronic TIA???s) the problem is a poor blood supply to the neurons. Dehydration robs the brain water and it slows energy production because water is found in the mitochondria and makes up 70% of the brain. This starves the brain slowly of oxygen causing long standing neuronal cell death and leads to a dementia. The neurons are completely normal???just starved for air and water. Autoregulation however is completely intact. In AD, the neurons are diseased from protein folding defects but the blood vessels can deliver a normal cerebral perfusion pressure. Protein folding is a key early problem in all neurodegenerative diseases. This means oxygen flow is intact in the AD patients??? brain.
The neurons however on the dynamic PET/SPECT scans show major hypo-metabolism and hypo-perfusions in the frontal and temporal lobes. Autoregulation is clearly uncoupled in AD and it is 100% tied to a loss of energy. Remember the only way we have to uncouple CBF from CRMO2 and keep the patient alive is anesthetic drugs. This begs the question???when we put a person with AD under a general anesthetic do they react differently since their neurons cannot control their own perfusion do to the formation of neurofibrillary tangles? Anesthesia literature says this is a true statement. So then why is it that a ketogenic diet, high in MCT oils, very helpful in improving cognitive function in AD? Here is where it gets real interesting.
The brain is an amazing organ of evolution. It makes up 2% of our body weight but draws 20% of our cardiac output. This means it is the ultimate energy hog. But one would expect that because of the amount of energy it uses to run the entire human body. Moreover, as humans evolved the neocortex (human parts of our brain) it increased the demand for energy to greater degree than primates. More brain tissue evolved means more oxygen is needed. This is why primates pound for pound are stronger than us. Their lineage chose muscle-skeletal strength to climb trees while we evolved brains to increase our thinking ability. This allowed us to forage for food with more diversity because we could think to find ways to forage better than we had. Forming social networks to use collective knowledge is an example. But this huge evolutionary advantage also came with a cost. A human can live without food for 30 days. They can survive for without water for seven days. But the human brain cannot do without oxygen for 4 minutes or it dies. It is clear water and oxygen are the fuel sources for the brain somehow.
Because of the brain???s high metabolic demands, when humans think or do any mental activity they can only activate about 2% of the total neurons in their brain to carry out the task when they are using glucose as a source of fuel. This has been shown by PET scan studies and more recently in fMRI studies using CRMO2 as the major variable. This limits our ability to use multiple systems at once. If we did we would pass out from the lack of oxygen due to the heightened CRMO2 by the neurons actively engaged. Remember that oxygen consumption in the brain is directly coupled to blood flow. When the human brain is running on a ketogenic diet as its primary source of fuel the ketone bodies directly down regulates genes that allow glucose to be utilized in neurons. Moreover, the ketone bodies allow us to use between 35 ~100% more total neurons than we could with the isocaloric dose of glucose as fuel. This means we can activate and use more neurons using less oxygen! That provides a huge macronutrient advantage for ketosis. It appears that the real advantage of ketosis from the brain???s perspective is an increase function and cognition. This is pretty amazing and in fact has been shown in many patients with neurodegenerative disorders like Alzheimer???s disease.
Remember my original point about how the brain works normally. Neurons determine how much CBF it needs based upon its own metabolic demands. CBF is tightly coupled to CMRO2 given the wide variations in blood pressures. BP is a function of plasma water content. A ketogenic diet works by uncoupling CBF from CMRO2! This means that eating a ketogenic diet allows a higher CBF while have a lower resting cerebral metabolism. Carbohydrates and proteins have never shown this benefit in any study I know of testing cerebral autoregulation. This means that a low carb, high MCT fat diet confers a significant metabolic advantages to the brain. The brain directly controls all efferent and afferent pathways of metabolism via leptin. The implications are big. Remember that food is thought to be our only a substrate source of electrons for our mitochondria???s electron transport chain in organic chemistry terms. This also means that somehow the electrons that come from these ketone bodies affects the neuronal ATP requirement of cerebral mitochondria. Is it possible they come from elesewhere or does the electrons from food have a quantum effect?
This was the essence of the question that I asked ???The Kracken??? at AHS. I asked him if all electrons are created equal? On the surface this sounds like an ???ignorant question??? until one thinks about the implications of these findings in the pathologic brain. Something has to allow for this metabolic advantage. So what is it? That is open for debate, but I think i have a solid answer. But this is where the physics papers come in that I was talking to Matt about.
We know experimentally that CMRO2 (cerebral metabolism) is tied directly to microtubule function and mitochondrial ATP production in the brain. The only way we have as neurosurgeons to uncouple neuronal oxygen consumption from cerebral blood flow and not kill neurons is inducing anesthesia. Today we don???t know precisely how anesthesia works, but Stuart Hameroff, MD (an Anesthesiologist at Univ of AZ) believes he does. His work is pretty amazing and I have been reading it for sometime. I just never put metabolism and physics together until today???s trip home. We know that volatile anesthetic gases act by Van deer Waals (London Convention) forces in hydrophobic pockets of select brain proteins to ablate consciousness. It???s called the induction of gamma coherence of neuronal microtubules. The quantum field theory mathematics and physics are quirky, but I think the answer to many unknown biologic forces will come back to Einstein???s core principles he laid out in 1905 and in subsequent papers. Most of you know that quantum mechanics deals with the physics , chemistry and biology at a subatomic particle level. Well, electrons from all types of sources and from foods fit that bill.
The real question is do electrons from different macronutrients have specific quantum biologic effects? Many of the things that have been mathematically predicted by Einstein???s quantum mechanical theory have been proven true by science today. For example, the presence of a black hole, a quasar, or the fact that time bends at the speed of light. When he first made the predictions he was mocked. He predicted a quasar and a black hole in the 20???s and until the Hubble telescope was deployed recently, we did not know for sure. We now know he was correct. Einstein???s mathematics also says that things that are of the same origin always remain connected in some fashion no matter how far apart they may exist in space or in time. This is his theory of non locality. I have been an Einstein freak my whole life. And I have been wondering for 15 years whether an electron from carbs, fat or protein, or somewhere else is somehow categorized differently than one another by metabolism. If so this could have major implications for a new understanding of all the biologic pathways in metabolism and in aging.
I can hear you thinking, I am drinking the woo woo now! No, I can promise you I am not. The reason I have been thinking about gamma coherence and ???if??? all electrons are really equal is because of this seemingly incongruent experimental effect of the ketogenic diet on brain metabolism. The real data implies something else is behind energy transfer in the brain. It clearly is different in the brain as I have laid out here. So would evolution select the brain about differently than any other organ in our body? I don???t doubt it, because evolutionary biology uses a strict fractal geometrical framework for evolutionary progression. I think the answer is in water. This post likely will stimulate the debate in the blogosphere about the real differences in macronutrients effects upon metabolism. At least, I hope it would.
I???m wondering out loud about how far reaching this effect may reach. But I now have a more complex puzzle to solve. Why does this happen with only a ketogenic diet? Why are carbs and protein afforded no such benefits? This needs to be asked don???t you think? And now you have the essence of what I was trying to ask ???The Chemistry Kracken???. Are all electrons really created equal or does our body account for the types of foods that certain electrons come from? I honestly think I know this answer, but I wanted to ask the smartest man in paleo; but I can not get away from why would a ketogenic diet high in MCT do something radically different to brain metabolism and CBF that carbs and protein do not. I think its a question that needs an answer. Remain curious folks!!!