Why Paleo And High Fat Diets Work

The human body is designed to consume complex and simple sugars (carbohydrates) as its primary fuel. This is absolutely scientifically indisputable. Our taste buds are designed to primarily seek out sugars and salts. We have no taste buds designed to taste specifically for meat, unlike your cat. Since we have no meat specific taste buds, most of the flavor of meat comes from the potentially carcinogenic flavor compounds that are created from the Maillard reaction, which takes place when meat is cooked. Most humans find the taste of raw unseasoned flesh to be unappetizing.

Our digestive tract contains relatively huge amounts of amylase, an enzyme that’s designed to breakdown starchy sugars.  Amylase is the most abundant enzyme in human saliva. The length of our digestive tract is identical to a chimps, as is the structure of our teeth. Our digestive tract is 12 times the length of our torso, compared to a 3 times length for carnivores. Humans have convoluted complex colon walls designed to extract maximum nutrients from fibrous plant matter, unlike carnivores that have smooth straight colons. Our metabolic system is optimized to burn carbohydrates directly rather than create them from protein, unlike a carnivore.

We have no teeth designed to tear flesh from hide or impale animals. Humans have no talons or claws designed to rip or slice flesh from bone. Our jaws move side to side which allows for the chewing and grinding of fibrous plant matter, unlike carnivores who can only move their jaws up and down. Carnivores do not grind their food, they rip and gulp.

Meat and dairy have no fiber, so consuming them causes humans to have constipated stools. The consumption of meat and dairy is the number one cause of constipation in humans. Our long intestinal length causes meat to rot in the bowel, leading to a 3x higher incidence of colon cancer among meat eaters.

Most carnivores can digest microbes that would kill a human, such as botulism, which is why humans are forced to cook meat before consuming it.  In fact, consuming animal fat causes the body to be flooded with bacterial toxins that cause inflammation, leading to insulin and leptin resistance.

All known carnivores pant to dissipate body heat, while plant eaters have sweat glands. It’s impossible for a carnivore to develop clogged arteries from consuming too much cholesterol, which is not true for herbivores. For most people, the sight of a bloody dead animal is naturally repulsive. I don’t know a single person that would consider popping a live mouse into their mouth. I could keep going on listing differences in physiology between carnivores and humans until I had an entire novel.

Since the human body is optimized to burn carbohydrates first, before burning fat and protein for energy, low carb high fat (LCHF) diets, such as the Paleo or Atkin’s diet, cause the body to enter a state of ketosis to obtain the energy it needs. Ketosis is a starvation response mechanism humans have that allows us to survive extended periods of famine. When humans stop consuming carbohydrates for energy, the glycogen stores in our liver get used up, forcing our bodies to consume fat. This is a starvation response mechanism = FOR EMERGENCY USE ONLY.

Studies indicate that high protein diets, which can induce long term ketosis, lead to a higher incidence of cardiovascular disease and cancer. One particular study of 43,000 Swedish women spanning 16 years found, “A one tenth decrease in carbohydrate intake or increase in protein intake or a 2 unit increase in the low carbohydrate-high protein score were all statistically significantly associated with increasing incidence of cardiovascular disease”.

Another study involving 73,000 people over 6 years found that, “Vegetarian diets are associated with lower all-cause mortality and with some reductions in cause-specific mortality.” These are not your typical 24 week bullshit 100 participant studies touted by the people pushing ketogentic diets. These are some of the most comprehensive dietary studies ever conducted in the history of modern medicine.

When the body enters a state of ketosis, hunger is dissipated. Again, hunger is dissipated because this is a starvation response mechanism. The body figures you must be living in an area that is subject to a famine since there are no carbohydrates being consumed, so it also reduces your hunger. Thus, you have the ability to think clearly about finding new sources of carbohydrates to fuel yourself while you manage to get by on proteins and fats during a period of famine.

Ketosis causes a build up of acetone in the body, which is dissipated through the breath and urine. Let me say that again. Ketosis causes a build up of nail polish remover in your blood stream, causing your breath to stink. Anyone think this is a healthy state to maintain for years on end? Your body can end up cannibalizing your bones to buffer this acid build up. Elderly people on a HFLC diet should be VERY concerned about developing osteoporosis. Not only should they be concerned about developing osteoporosis, but dementia as well. Studies have shown that risk for AD is greater in people who consume diets high in cholesterol, saturated fats, and total calories while avoiding fiber, vegetables, and fruits.

Whenever someone points to studies saying a chronic state of ketosis is not harmful, all you have to do is look at the duration of the studies to see they are severely lacking as evidence. Studies that take place over the course of 6 months to a year aren’t going to show any serious side effects because that’s the duration of time the body is supposed to be able to cope with a famine. Further, since ketosis induces weight loss, people are going to initially feel better if they were overweight to start with. Cardiovascular health will improve in the short term simply due to the weight loss, but as the Swedish study shows, those benefits don’t last over the long term.

Over the long term, it’s difficult to achieve sustained weight loss eating a diet of virtually no carbohydrates simply due to the calorie densities of the foods involved. Pure fat, such as any refined oil, contains 4000 non-nutritional calories per pound. A tablespoon of oil contains 100 calories, which is the same as an entire apple or banana. Of course, the apple or banana also comes packed with a ton of phytonutrients and fiber that will keep us healthy. Fiber is absolutely critical to maintaining a healthy intestinal bacterial flora – again, meat and dairy have no fiber and cause damage to the gut flora.

Every large civilization on the face of the Earth has fueled itself primarily on starches. We know a low fat high carbohydrate diet leads to healthy slim populations of people – without any calorie counting.  A billion Asians eat a diet primarily consisting of rice and vegetables. Asians who eat this traditional diet have virtually non-existent levels of obesity or metabolic disease. The same is true of any indigenous population of people who eat a starch based whole food diet. Do you honestly think all those skinny healthy Asians would be healthier eating a big fat steak every night with their bowl of rice?

And before the paleo people start screaming about the Massai and Inuit, it’s been published that neither of those tribes consume a ketogenic diet, and that the fermentation of their food leads to higher carbohydrate consumption than was previously assumed.

A plant based diet contains enough protein to power even the most athletic among us.  The finest endurance athletes in the world eat a purely plant based diet and engage in carb loading before races.  At most, humans need 10% of their diet to be protein, which coincidentally happens to be the level of protein that is present in most plant based sources of food.

I’ve come across several websites operated by doctors who claim that low fat diets don’t work when compared to low carb diets, or that low fat diets were found in numerous large scale studies to have no impact on various diseases or rates of obesity.  If you actually look at what those studies consider to be a “low fat” diet, it turns out that all of them are basing that claim on a diet which limits fat to no more than 30% of daily caloric intake, and none of them limit meat, dairy or fatty foods consumption.  30% fat intake is a mountain of fat compared to what you would get if you ate a whole food plant based diet, which typically clocks in at less than 10%.  At 30% fat intake, they may as well not be on any diet at all!  That’s 3 times the fat intake of a whole food diet!  30% is only 3% less than what the average US male normally consumes!

One other thing to consider is that if humans are supposed to eat meat as their primary fuel source, it would literally be impossible to feed everyone on the planet. Do you have any idea how many more resources it takes to raise meat as opposed to growing a starch?  It’s about an 80 to 1 difference in resource costs.  The world can live on starches, it can’t live on meat without mass starvation occurring from shortages.  People can live on a diet of nothing but potatoes indefinitely.  Try doing that with any other food source.

You can learn a lot more about this topic by watching this 10 hour lecture series given by a doctor.

Dr. Michael Greger explains how his grandma was cured of end stage heart disease after being sent home to die, who then went on to live another 31 years.  He also discusses the cause of insulin resistance and why people remain diabetic.

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  • Mashuri Clark

    We are indeed omnivores and have evolved to eat cooked meat. Since the discovery of fire, the human head has evolved towards smaller jaws, which has allowed for bigger brains to develop. As for taste buds, umami is becoming more recognized as human’s “meat taster” for, you guessed it, cooked meat: http://www.jyi.org/issue/cant-get-enough-of-umami-revealing-the-fifth-element-of-taste/

    • Umami flavor comes from glutamates, which are predominately found in seaweed and plants like tomatoes. It’s not a meat specific taste receptor.

      MSG is concentrated umami flavor, and that’s produced from plants, not animals.

      • jackson

        “Humans are adapted to eat meat in times of famine – period.”

        Then how is one to explain the Maasai in East Africa?

        The Maasai are a pastoralist tribe living in Kenya and Northern Tanzania. Their traditional diet consists almost entirely of milk, meat, and blood, which means their diet is as full of fats as the diet of people living in the West. Unlike Westerners, however, the Maasai do not have many problems related to lifestyle diseases.

        • First off, you’re singling out one micro sized, poorly studied, population, while simultaneously ignoring the billion people in Asia living off rice and vegetables.

          The Maasai do no live off milk, they live off millet, just like every other tribe in Africa. They do drink more milk than most, but they don’t live off it. At least 50% of their diet consists of millet and corn meal.

          I bet if you ate a diet consisting of 50% whole grain millet, you could get away with drinking a lot of milk as well and not get fat.


          “Yet another finding was the outcome of the fieldwork in Africa. Nadja Knoll´s study shows that the traditional story patterns about the Maasai diet are wrong. …The main part — more than 50 percent — consists of vegetarian food.”

          • You make the big error to think people is the same everywhere on Earth.
            Evolution didn’t changed just skin, hair, eyes color:
            It changed the brain and the digestive abilities of humans.
            In many different ways, depending on their diet.

            How do you explain Inuit and their 10-15% carbo diet?

            Hunter-gatherers and herders groups had better health than agriculturalists groups in the antiquity. They were higher, stronger, lived longer. They were just unable to feed a lot of people on that diet.

          • Learn to google bro:


            “in multiple studies the traditional Inuit diet has not been shown to be a ketogenic diet.[10][11][12][13]”…

            …Inuit actually consume more carbohydrates than most nutritionists have assumed.[14] Because Inuit frequently eat their meat raw and fresh, or freshly frozen, they can obtain more carbohydrates from their meat, as dietary glycogen, than Westerners can.[14][15] The Inuit practice of preserving a whole seal or bird carcass under an intact whole skin with a thick layer of blubber also permits some proteins to ferment, orhydrolyze, into carbohydrates.[14]”

          • Matthew Alexander

            This doesn’t rebut what he was saying. Humans needs some carbs, but a high carb diet is dangerous, and the evidence is mounting at an accelerating rate. That the Inuit got some carbs, maybe a few more than previously thought, doesn’t change the fact that humans ate fruit, vegetables and meat until very recently.

          • It does rebut what he is saying. He’s suggesting that these tribes survive on ketogentic diets. I’m proving that they don’t. If you want to argue that people can eat fermented meat and fermented dairy and not get fat and sick, then you might have a leg to stand on. Of course, that’s not the argument he’s trying to make.

          • Matthew Alexander

            No, he was saying the diet had a small percentage of carbs. You are claiming, perhaps correctly, that it was a bit higher than that. It doesn’t affect his principle point.

          • 10-15% carbs is enough to prevent ketogenesis in many cases. Even more if the carbs have a low glycemic index.

            The main problem with low carbs diets is when there are too much proteins and not enough fat to compensate for the energy needed to dispose of the proteins in excess.
            In fact, there is the “Rabbit Starvation” when someone eat too much proteins and not enough fat or carbs.

            Traditional Inuit diets derive approximately 50% of their calories from fat, 30-35% from protein and 15-20% of their calories from carbohydrates, largely in the form of glycogen from the raw meat they consumed.

            This diet is high fat, high protein, low carbs and it is not ketogenic. You just wrote these diets work because they are ketogenic, but apparently they are not.

            What you do not understand is the effect of different nutrients on hunger, fat storing, fat burning, etc. The balance is pretty complicated and not all people react in the same way to them. For this reason categorical declarations are often wrong.


  • LogicalReason

    Another Excellent argument, perfect for radio. Michael, what’s your email? I’d like to talk to you about getting you on the radio. send me an email at consulting@lvmglobalmarkets.com

  • Christan

    My weight loss tactic works every time. It’s called a mountain bike!

    • Exercise is important, but it really is pretty worthless when it comes to losing weight for most people. A 200 lbs 6′ tall man doing high impact aerobics for an hour burns around 640 calories. That’s about 1 Burger King Whopper.

      So if you work out like a savage for an hour straight, you can treat yourself to one burger, no fries.

      • Christan

        I would recommend a mountain bike to just about anyone. Your going to spend about four to six hundred on a bike, another thirty on a good gel seat and camel back. I also like to have a mileage gauge and light.

        • Yeah, bikes are one of the best forms of exercise there is.

  • Daniel Harley

    “Studies indicate that diets which induce long term ketosis lead to a higher incidence of cardiovascular disease. One particular study of 43,000 Swedish women spanning 16 years found, “A one tenth decrease in carbohydrate intake or increase in protein intake or a 2 unit increase in the low carbohydrate-high protein score were all statistically significantly associated with increasing incidence of cardiovascular disease”.” –

    This study did not look at ketosis; indeed, a high protein diet does not lead to ketosis, because protein is converted to glucose via gluconeogenesis.

  • Daniel Harley

    “One other thing to consider is that if humans are supposed to eat meat as their primary fuel source, it would literally be impossible to feed everyone on the planet. Do you have any idea how many more resources it takes to raise meat as opposed to growing a starch? It’s about an 80 to 1 difference in resource costs. The world can live on starches, it can’t live on meat without mass starvation occurring from shortages. People can live on a diet of nothing but potatoes indefinitely. Try doing that with any other food source.”

    I don’t think you, somebody with an interest in Austrian economics, really believe the above statement. It contradicts basic micro. If we cannot feed the planet on meat the way that meat is currently produced, the cost will increase, driving producers to discover new ways of producing meat at lower prices. We already have lab grown meat. Can you name an example of another good that, through popularity and the cost of production, has disappeared?

  • Daniel Harley

    Sorry to post separate comments. I’m not spamming.

    “A tablespoon of oil contains 100 calories, which is the same as an entire apple or banana. Of course, the apple or banana also comes packed with a ton of phytonutrients that will keep us healthy.”

    Take a look at the micronutrient content of liver: http://chriskresser.com/natures-most-potent-superfood

  • Daniel Harley

    Why do my comments keep getting deleted? :/

    • I deleted them because I feel your comments are intentionally misleading, and ignore the bulk of the evidence presented. You came on here to defend eating shit that will kill people – and you know it.

      • Daniel Harley

        I’m really disappointed with you, Mr Suede. I’ve been reading your blog for years and have always found you to be incredibly intelligent, informative and entertaining. I love the range of topics that you cover here and everything you write is always incredibly well researched, and this includes the recent posts on veganism. I said before that I agree with you – a vegan diet is probably much healthier than the standard western diet and the studies you’ve posted are comparisons of just that: SWD v veganism.

        But you’re wrong about me. I have a personal interest in the paleo diet, which I’ve eaten since 2012 when I was 18 stone (252 lbs). Thanks to my diet, for the last 3 years I’ve been a steady 11 stone (154 lbs). What’s more, in 2013 I went to teach English in China and to get my work visa and private medical insurance I had to undergo a thorough health MOT which confirmed that I am completely healthy; my blood work, cholesterol, triglycerides, CRP, etc came back exemplary. My diet is not making me unwell.

        The paleo diet I consume is macronutrient blind – it’s a fools errand to concentrate on carbs v protein v fat. The answer to good health is to eat whole, unprocessed foods from a variety of sources, including plants (starchy and non-starchy) and animals. My diet resembles that of the Hadza, which your own guru McDougall agrees IS healthy! So no, I am not promoting a diet that I know will kill people. I am promoting a diet that the man you’re telling everybody to listen to agrees is healthy – and you know it.

        Plus, I’d have hoped you would have acknowledged the mistakes you made in this blog post. Because of gluconeogenesis, high protein diets do not encourage ketosis and you know any Austrian worth his salt would disagree with you on the sustainability of eating meat.

        You’ve let some much less informed comments remain in the comments section; it’s disingenuous to say you’re removing mine because they are ill-informed.

        • How old are you? Mid 20s? And you’ve been doing this diet for how long? 3 years? You think this diet of yours is going to keep you healthy into old age?

          When I was in my 20s I ate complete shit. I mean I ate total garbage. I drank heavily, I chain smoked, I ate meat every day, I barely worked out, etc.. etc.. etc..

          Guess what?

          I was perfectly healthy all through my 20s. No high blood pressure, I never got fat, I had good cholesterol, etc.. etc..

          I started to get fat in my 30s, as you may have seen from previous videos I’ve made. My blood pressure started to creep up, my blood work wasn’t as good, I was running out of breath, etc.. etc.. all the things we associate with eating a western diet.

          I surmise that the only reason you’re not sick is because you’re young. As I mentioned in the article, ketosis will make you lose weight. That doesn’t mean its healthy for you.

          I just showed you 2 massive health studies that ran for years, which prove beyond any doubt that meat consumption will kill your ass deader than a hammer.

          Your anecdotes don’t mean anything.

          • Daniel Harley

            You’re right, I’m 24 and there’s little I can conclude from my own N=1, but I think it’s compelling that I was overweight with high cholesterol and by just changing my diet to a paleo diet I am now the correct weight and my cholesterol has normalised. Young bodies can cope with a lot of crap – another evolutionary adaptation, because we need to be healthy while we’re virile – but my health has definitely improved thanks to eating a paleo diet.

            I think it’s a bit far-fetched to suggest a whole foods diet that includes meat is going to kill me, even if meat consumption were contraindicated (which I don’t think it is). There are plenty of people eating a diet that contains meat who are perfectly healthy. There are plenty of vegans who get fat, develop cancer etc. Steve Jobs developed a type of pancreatic cancer linked to the insulin-secreting beta cells of the pancreas, which are the cells that take a beating when you consume too much fructose. Veganism didn’t save him, despite the hilarious claims of some in the vegan community that his cancer must have developed years earlier in life and that the veganism was the only thing keeping him going!

            Mark Sisson seems to be enjoying pretty good health, and he’s been eating a paleo diet for a long time, and there are many others in the paleo community like him. Also, paleo originator Boyd Eaton is still going strong, having lived most of his adult life consuming a paleo diet. Take a look at him:

            The studies that you have provided do not prove beyond any doubt that eating meat is deadly because they don’t control for the type of protein being consumed. Nobody doubts that processed, protein-containing foods high in trans fats will kill you. I’m happy to concede that replacing your Dominos peperoni pizza with a potato and some broccoli will do you some serious good. This is what your studies show.

            Also be very careful of studies based on food frequency questionnaires. They’re notoriously unreliable.The Swedish study asked women to confirm in detail what they had eaten in the last 6 months! C’mon! I can’t remember in any detail what I ate two weeks ago. Some observational epidemiology can be good, but a lot of it is poor.

            You quoted two studies. I previously provided you with this link (http://wholehealthsource.blogspot.co.uk/2015/03/is-meat-unhealthy-consolidated-links.html) to Stephan Guyenet’s multi-part series covering pretty much all of the relevant, well designed research into meat consumption. Stephan is an unimpeachable researcher with no axe to grind and his conclusion is that unprocessed protein from meat, seafood, and eggs is perfectly healthy, with the exception of red meat, which he thinks is possibly unhealthy, although the studies are inconclusive.

          • Mark Sisson happens to be a genetic freak that has more fat satiating sensors in his stomach and he has a body that can more readily clear cholesterol than most other people. Of course, his body fat and cholesterol are still high. He’s not down into the single digit body fat range where the fat free vegans are.

            Some people can eat a western diet and not get fat because they won the genetic lottery. Some people can eat a western diet and not develop heart disease because they won genetic lottery. Nature makes sure that some of us will survive no matter how badly we try to commit mass suicide as a species.

            The same is true of Steve Jobs, only he just happened to be on the losing end of the genetic lottery. Speaking of Steve Jobs, his fruit based diet kept him alive wayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy beyond his expected expiration date. If you want to learn about what killed Steve Jobs, watch this:

            I linked a 10 hour presentation on this subject at the end of the article. Go watch it. I’m going to ban you from posting on here if you try to make one more post on this blog without watching all of those videos first. You can exclude the lectures where his wife is presenting.

          • Matthew Alexander

            And when Method actor Ashton Kutcher imitated Jobs’ diet? He started getting the same problems.

          • Ashton Kutcher died of prostate cancer? Oh, you must mean his pancreas levels went “out of whack,” according to Kutcher, without him explaining what that actually meant. – I’m curious why millions of people who eat a plant based diet don’t also experience this.

          • Matthew Alexander

            “Ashton Kutcher died of prostate cancer?”
            Because that’s what I said. [eye roll]

          • Matthew Alexander

            “Veganism didn’t save him, despite the hilarious claims of some in the vegan community that his cancer must have developed years earlier in life and that the veganism was the only thing keeping him going!”
            Doctors say the same thing about the flu vaccine!

        • Matthew Alexander

          I have had the same wonderful experience with paleo/primal. I lost 61 pounds in six months – and much of that time I was still eating high quantities of food – got rid of a number of nagging issues, and feel more energized. A lot of the benefit is the little stuff, like being able to stuff yourself during a meal and play a soccer game fifteen minutes later because you don’t feel at all weighed down. Low carbs.

          • I hope you get your cholesterol levels checked on a regular basis. Sisson’s are high. While you can lose weight on a ketogenic diet, that doesn’t protect you from the other harms that can come from eating large quantities of meat, such as heart disease and prostate cancer.

  • Mike Ryan

    Tract, tract, tract. There’s no such thing as a digestive track. Sheesh!!!
    You write like a teenager…

  • Phil Champagne

    Another similar view is that of the Weston A Price Foundation.

  • Roman A. Cotton

    Our ancestors did have much more powerful jaws and much bigger teeth than we do. The neat thing about stone tools is they’re essentially food processors outside of our mouths, so they enable us to cut meat into smaller pieces, maybe chewable pieces. That was a big benefit to making stone tools in terms of our diet. I for one cant eat grains. Id also like to add that Ketones are a more efficient fuel source for the brain. I don’t always stay in ketosis but I do breifly sometimes. I also do intermediate fasting which would be horrible if not for my fat adapted metabolism. Gene Expression is an awesome thing. Especially because meat requires less energy to digest. I like chewing on my raw chicken livers and bone marrow. It feels more “natural” than eating grains. I don’t know if we were wired for meat….but I think it played an important role in our evolution.

    • Roman A. Cotton

      Also your gut flora can shift cultures according to your diet the best it can.

      • Well, I’m obviously not going to change your habits. I hope you don’t find out what a mistake your making by ending up with heart disease or some other related illness. Word of note, erectile dysfunction is highly correlated with heart disease as they are both caused by the same process. Some doctors consider erectile dysfunction to be an early warning sign of heart disease, so if your wiener stops work’n, get yourself checked out.

        • Roman A. Cotton

          So we look at the gastro-intestinal tract, and completely ignore the dentition, which appears to be that of omnivores. The presence of incisors, cuspids and bicuspids indicate that tearing/cutting was a primary mode for eating, rather than crushing/grinding. However this is just my opinion, and I could be wrong. Also… my cholesterol is high but i don’t eat enough carbs to spark any sort of inflammation. The mutations of the genes for amylases were introduced only when man began to cook grains. But the point is… when 2 million years ago the genus Homo began consuming more meat, it didn’t need any adaptation at all, because enzymes for raw meat had always been present. Plus there is no scientific evidence that our digestive system is not made to handle large quantities of meat perfectly.

          • Well, actually there is. The human digestive tract can’t fully digest meat, so a portion of that meat ends up in the colon where it can undergo putrefaction. Further, meat consumption has been linked to colon cancer. In populations that consume little to no meat, heart disease and colon cancer are exceedingly rare. Also, meat has no fiber, so meat consumption can cause severe constipation.