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Inside Ketogenic and High-Fat Diets, with Dr. Timothy Noakes

We are discussing research about ketogenic diets and sports performance. Studies have come out concluding contradictory things about the effects, benefits and risks. Researchers have strong opinions on both sides. Will going keto make you faster?

Ketogenic Diet

If we had to summarize sports nutrition in one word it would probably be… controversial. Or maybe just confusing. Endurance sports guidelines tell us we need to pack in the carbohydrates. Then we hear about Team Sky and other prominent athletes resorting to a nearly carbohydrate-free diet. So which one is best, and frankly do we even need to be eating the same way a grand tour rider eats?

One thing that’s certain is that in the world of nutrition, “keto” has become a buzzword — and not only in the sports world. Terms like “ketogenic diet” have become some of the most searched dietary terms on Google. It’s even made its way to the most important forum of public opinion — the Saturday morning group ride conversation.

But what is a ketogenic diet? And in a sport where high-carb pasta dinners and simple sugar sports drinks have been the norm for decades, why are we even talking about a very low-carbohydrate, high-fat diet? Today we’ll delve into that subject.

First, what is meant by a “ketogenic diet” and what are ketones? Evolution felt there was an important reason we evolved to use them, so what exactly do they do?

We’ll discuss the difference between a ketogenic diet and a high-fat/low-carbohydrate diet, and why the latter may be the more important one to discuss.

Are there potential health benefits, outside of performance, of trying a ketogenic diet? We’ll take a look.

What does the current research say about the ketogenic diet and sports performance? There are studies concluding contradictory things, and researchers have strong opinions on both sides.

Finally, if you’d like to try a ketogenic or high-fat diet, we’ll talk about the best ways to go about doing it, and also discuss why a less extreme high-fat/low carbohydrate diet may be better.

Our primary guest is a researcher who has become one of the most well-known faces of the high-fat movement — Dr. Timothy Noakes. Dr. Noakes has been at the center of endurance science and sports nutrition research for decades. He wrote, among other books, the very popular “Lore of Running” in the 1980s.

Primary Guest
Dr. Timothy Noakes, renowned nutrition scientist and author of “Lore of Running”

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  • Cox, P. J., & Clarke, K. (2014). Acute nutritional ketosis: implications for exercise performance and metabolism. Extrem Physiol Med, 3, 17.
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  • Kearns, C. E., Glantz, S. A., & Schmidt, L. A. (2015). Sugar industry influence on the scientific agenda of the National Institute of Dental Research’s 1971 National Caries Program: a historical analysis of internal documents. PLoS Med, 12(3), e1001798.
  • Kearns, C. E., Schmidt, L. A., & Glantz, S. A. (2016). Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents. JAMA Intern Med, 176(11), 1680-1685.
  • Phinney, S. D., Bistrian, B. R., Evans, W. J., Gervino, E., & Blackburn, G. L. (1983). The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism, 32(8), 769-776.
  • Phinney, S. D., Bistrian, B. R., Wolfe, R. R., & Blackburn, G. L. (1983). The human metabolic response to chronic ketosis without caloric restriction: physical and biochemical adaptation. Metabolism, 32(8), 757-768.
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  • Volek, J. S., Noakes, T., & Phinney, S. D. (2015). Rethinking fat as a fuel for endurance exercise. Eur J Sport Sci, 15(1), 13-20.

Episode Transcript


Intro  00:00

Welcome to Fast Talk, the VeloNews podcast, everything you need to know to ride like a pro.


Chris Case  00:13

Welcome to Fast Talk, I’m Chris Case, managing editor of VeloNews, joined by my always diplomatic co-host, Coach Trevor Connor. If we had to summarize sports nutrition in one word, it would probably be controversial, or maybe just confusing. Endurance Sports guidelines tell us we need to pack in the carbohydrates, then we hear about Team Sky and other prominent athletes resorting to a nearly carbohydrate-free diet. Which one is the best? Frankly, do we even need to be eating the same way as a grand tour rider? One thing that’s certain is that in the world of nutrition, Keto has become a buzzword, and not only in the sports world, terms like Ketogenic diet have become some of the most searched dietary terms on Google, it’s even made its way to the most important form of public opinion, the Saturday morning group ride conversation, but what is a Ketogenic diet? In a sport where high carb pasta dinners and simple sugar sports drinks have been the norm for decades, why are we even talking about a very low carbohydrate, high fat diet? Today we’ll delve into that subject. First, what is meant by a Ketogenic diet and what are Ketones? Evolution felt there was an important reason we evolved to use them, so what exactly do they do? We’ll discuss the difference between a Ketogenic diet and a high-fat, low carbohydrate diet, the latter may be the more important one to discuss. Are there potential health benefits outside of the performance of trying a Ketogenic diet? We’ll take a look. What does the current research say about the Ketogenic diet in sports performance? There are studies concluding contradictory things and researchers have strong opinions on both sides. We’ll discuss. Finally, if you’d like to try a Ketogenic or high-fat diet, we’ll talk about the best ways to go about doing it, and also discuss why less extreme, high fat low carbohydrate diet may be a better, healthier choice. Our primary guest today is a researcher who has become one of the most well-known faces of the high-fat movement, Dr. Timothy Noakes. Dr. Noakes has been at the center of endurance science and sports nutrition research for decades. He wrote, among other books, the very popular, Lore of Running, in the 1980s. But while training as a high-level marathon runner, Noakes became diabetic, which set him on the path to look for alternative solutions to the accepted high carbohydrate dietary approach of the 80s and 90s. In Episode 23, we interviewed Dr. John Holley, who along with his wife, Dr. Louise Burke, is another top name in the world of endurance nutrition research. They’re both strong proponents of the use of carbohydrates for sports performance, however, if you look back at both Noakes and Holley’s early research, you’ll notice something interesting, it’s the same. Noakes, Burke, and Holley did a lot of the early research on both high carbohydrate and low carbohydrate diets together, and yet the same research led them to very different conclusions. In Episode 23, Holley made a strong case for why we need carbohydrates. In this episode, Noakes will take on a lot of that same research and explain why his interpretation is fundamentally different. Along with Dr. Noakes, we also talked with Joe Dombrowski, of the EF Education First Drapac World Tour team, who expressed the skepticism shared by many other riders in the pro peloton. We also hear from Sepp Kuss, of the Lotto NL Jumbo World Tour team, while he hasn’t tried a Ketogenic diet himself, Sepp talked about a team training strategy of quote training high and training low, that is starting some rides packed with carbohydrates while doing other rides on no carbohydrates. Are you ready? Let’s make you fast.


Why Dr. Timothy Noakes Believes in the Ketogenic Diet

Dr. Timothy Noakes  04:00

I converted seven years ago to this diet and I was in terrible shape at the time, and I wrote the book called, Lore of Running, which most runners will know the book, and there is promoted the idea to eat a high carbohydrate diet. It took me 33 years before I realized I got it completely wrong and had to change, and I realized I got it wrong because my own running had got so bad and I got fat, and it turns out that I also developed type-two diabetes, despite the fact that I’d run 70 marathons and or ultra-marathons during that time. I was overweight by the end but not too overweight.


Trevor Connor  04:38

Guessing some of that’s because you were probably doing a little more of the traditional sports nutrition and just, you know, I in the old days used to try to force down the 700-800 grams of carbohydrates per day, I imagine you were doing something similar?


Dr. Timothy Noakes  04:51

Absolutely. And I used to think that fat was so bad that if I could get it through a day without eating fat, I would think that’s been a fantastic day, and now, of course, I realized it was the opposite. To cut a long story short, I read the book, New Atkins for a New You, and then I read Loren Cordain’s book, and then I decided that it’s time to change. So, I started the Ketogenic, low carbohydrate diet, and within six weeks, my running had gone back 20 years, I went back to running performances, I lost run when I was 14, so I went back from being a 60-year-old to a 40-year-old, and I couldn’t believe it. It was just an amazing change for me. So, I can’t thank all the people who’ve driven the Keto diet over the years for what they’ve done, they certainly saved my life, and it’s gone much beyond that because I’m glad to report that in the last month, my blood results show that my diabetes is in complete remission.


Trevor Connor  05:50

That is great to hear, and congratulations.


Dr. Timothy Noakes  05:52

Thank you. Thank you.


Chris Case  05:54

So, let’s dive in a little bit more. What exactly do you mean when you say you’re on a ketogenic diet? How low are we talking about in terms of carbohydrate consumption?


What Is a Ketogenic Diet?

Dr. Timothy Noakes  06:04

Yeah, I must say that I went on this diet because I read Steve Phinney’s book, and you know, I have enormous respect for Steve, and when Steve says something, I believe him. So, he pushes the Ketogenic diet, I find it incredibly difficult to be at a high level of ketosis. So, most of the time, my ketone bodies are between .3 and about 1 maximum. For that, that is ketosis, it’s not the sort of ketosis that a lot of people want to get to three or four, I just can’t get to three or four, I have to starve and not eat, and to run a couple of hours a day to get to that level of ketosis. So, I think it’s different for all of us. So, but if you say that a blood ketone level of .3 is ketosis, then it is easy to get there, and I get there by eating less than 25 grams of carbohydrates a day, and I’ve been eating that diet, as I said, for seven years. Getting a higher value, I do not know how I could do it. I think there’s been an adaptation. I think I was more ketotic when I started, but seven years later, I’m not quite as ketotic.


Technical Definition

Trevor Connor  07:07

So, my understanding is the technical definition of a ketogenic diet is 50 grams or less of carbohydrates per day. I’ve certainly heard what you’re saying, that everybody is individual and some people can eat that diet and actually their blood ketones don’t rise that much.


Dr. Timothy Noakes  07:25

So, you see, what I don’t understand is, if you can accord a ketogenic diet, and it must be one that generates a significant level of ketosis. So, we can either classify that as low carbohydrate, or as low carbohydrate, high ketones, or something like that. In my feeling, the key is to get the carbohydrates down, and when ketosis happens, that is an individual thing. I think Steve Phinney believes that you really need to get the ketones about two or three to get all the benefits, and I suspect he is right. I suspect from my own experience, that we’re not fast for 24-hours, I really feel a lot better, and I’m more mentally astute than if I only fast for 12-hours or so. So, I think there is something beneficial in getting your ketones up into that range, but I’m not sure that it’s easy for all of us to sustain it. So, I like to say what is easy to sustain is a carbohydrate diet below 50 grams of carbohydrates a day, and once you get into the diet, it’s simple. To keep your ketones very high, is much more difficult because it means you really have to go on a very high-fat diet, and you have to fast a lot and you probably have to exercise a lot for many of us. So, that’s my definition. I prefer to advise people to count big carbohydrate grams.


Ketosis and Ketone Bodies

Trevor Connor  08:39

So, for our listeners who are new to this whole concept, what exactly do you mean by ketosis or ketone bodies?


Dr. Timothy Noakes  08:47

So, ketone bodies are a crucial part of our metabolism, and they one of the reasons why humans survive during starvation. So, the simple answer is that ketone bodies are produced by the liver whenever you’re not eating carbohydrates, or you’re starving, those are the two mechanisms, and the ketone bodies are produced by the liver in response to increase fat coming into the liver in the form of free fatty acids. The reason why the liver produces the ketone bodies is to replace the glucose that it can’t produce. So, all of us know that the brain needs glucose, a certain amount of grams of glucose per day to function, and if we didn’t have a reserve capacity, we wouldn’t get through starvation, we would all die, our brains would stop functioning. So, in acute starvation, the ketone bodies rise very quickly, and they then replace glucose, and so as a consequence, your brain can function normally, burning ketones and a little bit of glucose that the liver continues to produce. And with time, the ketones become the dominant fuel for the brain if you continue to starve yourself. Ketone bodies are also excellent forms of fuel for muscle, and so you get the double benefit that you’re using a fuel that is really good for your brain but can also be used by muscles. The key for ketosis is you want to keep your blood insulin levels low because that’s what keeps the fat in the fat cells, the insulin inhibits fat released from the fat cells, but as you reduce your carbohydrate intake, or you stop, then the insulin levels drop, the free fatty acids are released from the fat cells, and they come to the liver and you start to produce ketones. That’s only the metabolic side, but there’s a whole bunch of other aspects of ketosis are which Steve Phinney and Jeff Verlick are world authorities, and they seem to suggest that ketones have additional functions in changing gene structure and immune function and making you a much healthier person. But that’s an area that I’m not an expert on.


Trevor Connor  10:56

One of the criticisms you frequently hear of low fat, or a Ketogenic diet is why in the world, would you want to emulate starvation? I do think that is, personally, I think that is one of the misconceptions. When you look back in our hunter-gatherer societies, for one thing, they were not in a starvation state as much as people would think, but they did frequently fast. But more importantly, you brought up the fact that the other thing that can produce ketosis is very low carbohydrate consumption, and in most hunter-gatherer societies, carbohydrates were a seasonal food. Certainly, in the winter, in the colder months, you couldn’t really consume much in the way of carbohydrates, you had to eat a high-fat diet.


Criticisms of the Ketogenic Diet

Trevor Connor  11:39

Yeah, precisely. And you know, my heritage is from the north of England, and the north of England was and the ice until 3000 years ago, so what was my great, great, great, great, great grandparents, my ancestors eating? They weren’t eating cereals and grains, and fruits and veggies, they were eating fat animals. So, also think it’s depending on where you live, where you’re born from, as how many carbohydrates you can actually cope with. My general feeling, and perhaps you’ll amplify this, Trevor is that if you look at hunter-gatherer populations, most of them stick below by 30% carbohydrate in the diet, and Americans were eating about 35% carbohydrate in the 1960s, and they were lean, and then they’ve pushed it up to 40-50%, and that seems to be the critical area. Once you go over about 30% of carbohydrates in your diet, then you start to get all the problems because we’re insulin resistant, and we can’t metabolize the carbohydrates well. So, if we’re eating 10, or 15% carbohydrates in the diet, you should be fine if you’re not seriously insulin resistant, but it’s once you go above 30%. So, it’s not to say all carbohydrates are bad, it’s really the person, it’s you the individual, the way you can metabolize that carbohydrate or not.


Trevor Connor  12:55

And that does bring up another really important question, we’re talking about macronutrient ratios, and I certainly have a bias on this, but do the foods matter? And is it just eat high fat, it doesn’t matter the source of the fat? Or do you feel you should be focusing on some foods and not others?


Foods To Eat on the Diet

Trevor Connor  13:15

Oh, definitely the food, the quality of the food is terribly important, and obviously, we go to grass-fed meat and grass-fed fat and so on, and fatty fish and avocados and all those things which are, which are extremely healthy. Absolutely right, you have to eat clean, to get the greatest benefits. I think in the long-term, we will begin to realize that you can have a Ketogenic diet, but that’s a disaster because you’re eating the wrong foods. Whereas the diet that is the most natural from the most natural products, and the most naturally raised animals, that to me would be the best. So, for example, I know that in your country, you know, buffalo might be extremely healthy because it’s raised on grass, and of course, it’s grass-fed beef, but that’s not quite so easy to come by. In this country, we have a lamb that is raised in the felled, the countryside, and there is nothing to eat there, but these animals thrive on it, they can’t survive on anything about this, that food and they’re incredibly healthy. So, their fat is, is good. I think Canadians would say the salmon is really healthy. So, I think in each country you have to look for where is the animals that are produced the healthiest way. That’s what you should be eating.


Trevor Connor  14:25

Yeah, because I’ve talked to people who are on ketogenic diets, and that’s always been my concern is they say, “Oh, I’m eating very healthy and ketogenic,” and I say, “What do you eat” and they go, “I have bacon for breakfast, and I have a stick of butter for lunch,” and not many vegetables. That is when you have to sit them down and say, “That’s not the way to do it.”


Trevor Connor  14:44

Yeah, exactly. Yeah, it’s correct. So, they need to eat really healthy fats from healthy animals.


Chris Case  14:50

Let’s spend a little time discussing the health benefits outside of sports of the ketogenic diet. Whether it pertains to the brain, type two diabetes, heart disease, those types of things.


Health Benefits of the Ketogenic Diet

Trevor Connor  15:02

So, what I’ve learned in the last seven years, which was not taught in medical school and is not taught in any single medical school I know in the world, is that the biggest medical problem in the world is insulin resistance. Insulin resistance is the inability to metabolize carbohydrates effectively and every time people like myself eat carbohydrates, we over-secrete insulin, were hyperinsulinemia, and that then causes damage because insulin is a highly damaging hormone, it makes us fat, it ultimately leads to heart disease, obesity, and probably also cancer. So, the whole focus of chronic degenerative disease should be on diet, and we should be saying, listen, if you’ve got high blood pressure, you haven’t got high blood pressure, you’ve got insulin resistance, and you’re eating a high carbohydrate diet, and that’s expressing itself as high blood pressure, the same for obesity, the same for heart disease, or heart sample cancer. And until we get that message out, we’re not going to help people, because the message we have is that its cholesterol, you see, so you can see the low-fat diet, and you must take statin drugs, all that does to people with insulin resistance, it makes them more diabetic, more obese, more at risk of Alzheimer’s disease, more interest of cancer. So, it’s the treatment is wrong, because this is a metabolic nutritional disorder, and what I show and every other great study that has been done showing that low carbohydrates, reverse these conditions, and as long as you’re insulin resistant, you can be extremely healthy, but just don’t eat more than 25 grams of carbohydrate a day. So, that’s the message that we’re trying to get out, and it’s very difficult, because neither industry, the food industry nor the pharmaceutical industry want that message to come out.


Trevor Connor  16:43

We also talked in a previous podcast about that JAMA study that came out recently reviewing the sugar industry, and how back in the 50s and 60s, when the research was starting to come out showing that sugar was related to heart disease, they actually started funding research to point the finger at fat.


Trevor Connor  17:01

Exactly. And they all promote the idea that polyunsaturated fats are healthy and more healthy for you than saturated fats, and so the dietary guidelines have no hope, because they’re always driving dietary guidelines, and they will never allow saturated fat to be sought of as anything but toxic.


Trevor Connor  17:18

Going to the polyunsaturated fats, it’s still that omega-three to omega-six ratio is very important. Would you agree that if most people on a Western diet could increase their omega-three and decrease their omega-six, that would be a healthier approach? Correct?


Trevor Connor  17:34

I’m talking mainly about vegetable oils, with lots of trans fats and all sorts of other things that we don’t even know about yet. Those are the ones I mean, it is utterly remarkable, the evidence against vegetable oils is so strong, and many people think that the vegetable oils are almost as toxic as sugar, and that the chronic diseases are not just a function of carbohydrates, they’re probably also a function of the vegetable oil intake.


Trevor Connor  17:58

So, to say, I think the key message here is that there’s been an extraordinary amount of research coming out lately showing that most of these chronic diseases, heart disease, cancer, diabetes, they’re all preceded by chronic inflammation, and likewise, there’s now a lot of research coming out showing how much simple carbohydrates contributed to inflammation.


Dr. Timothy Noakes  18:21

That’s the message we need to get out.


Chris Case  18:24

How does somebody know when they’re insulin resistant?


Insulin Resistance

Trevor Connor  18:27

The first thing is you start putting on weight, and that’s around your middle and you get what’s called the insulin role, the role of fat around your tummy, if you’ve got that your insulin resistant because that’s we call the insulin roll, it’s there because you are over- secreting insulin response to a high carbohydrate diet. Then you get angry, your mood will change, and often meals you often get, you get angry, and you start to eat more frequently, eating every three hours because you’re addicted to the foods, and you have to keep your blood glucose as normal, etc. So, those are some of the things and then eventually your exercise performance starts to fall, and you’re always craving carbohydrates as well. So, those are some of the indicators, the best marker is to measure your fasting insulin level, that’s the insulin level when you wake up, and once it goes about six units, the micro international units per ml I think it is, once it goes above six you’re in trouble, and six is way below the normal value. Most doctors will say, your values below 25, that’s fine. It’s not so true. If you’re above six, you’re already insulin resistance. The next thing that happens is your glucose starts to rise during the day or after meals, and that then affects your red blood cells and they become what we call glycated, and we can measure that as the glycated hemoglobin or HBA1B value, and if you HBA1B is 4.5-5, your carbohydrate sensitive, if it’s over 5.5 you are diabetic, you won’t be told that, you have to get to 6.5 before doctor will diagnose diabetes, but I can tell you if your values 5.5 you are insulin resistant, and you’re on the route to diabetes, and you will have diabetes in 10 years time. So, if you values about 5.5, you are insulin resistant, cut the carbs, and you will never develop diabetes. So, that’s one of the best tests is that glycated hemoglobin, and we can tell all the listeners that if you are worried, you putting on a little bit of weight and you just a little more lethargic, you haven’t got so much energy, just measure your fasting insulin, and see. If those two values are elevated, that’s it, bye carbohydrates, you’ve got to cut them back to let’s say below 100, maybe below 75, maybe below 50. But you will immediately start to feel better, and your values will start to improve. One of the best tests of insulin resistance is how you respond to a high carb, high-fat diet. If you respond positively to a high-fat diet you are insulin resistant.


Trevor Connor  20:57

Another little catch 22 with insulin is that insulin actually spikes hunger signals. So, people who are insulin resistant, you eat carbohydrates, you’re going to get higher and higher insulin levels, that’s actually going to make you more and more hungry and you’re going to want to eat more and more carbohydrates, and you get quite a vicious cycle going, and that’s always been my belief why you have people who are dramatically overeating every day and saying but I’m hungry all the time.


Trevor Connor  21:24

Exactly, exactly right. And others will tell you that insulin is a satiating hormone, and that’s nonsense.


Trevor Connor  21:30



Dr. Timothy Noakes  21:31

It’s one of the hunger hormones.


Trevor Connor  21:34

If you think you’re confused by these low carb, high carb trends, you’re not the only one. Chris and I have interviewed many pros who have teammates trying the high fat or keto diet, and many have team nutritionists who are now addressing it with athletes who want to give it a try. The general impression we’ve gotten is there’s some interest, but it’s tempered by a fair amount of skepticism. Riders are hearing about potential gains, but still reluctant to try more than a day or two at a time. That was certainly the feeling of Joe Dombrowski, a world tour rider with EF Education First Drapac, presented by Cannondale.


Chris Case  22:06

Do you or have you believed in a ketogenic diet for performance in the past?


Joe Dombrowski: Ketogenic Diet and Performance

Joe Dombrowski  22:12

I’ve done, I would say a lot of it, but sort of like a sprinkling of like, carbohydrate-restricted training before. Am I a believer? For me personally, I don’t think that it works very well, this really running the engine hot, high-end anaerobic efforts can be hard for me, and low carbohydrate diets aren’t going to help you with that. Whereas if you know you’re sort of lipid power, fat metabolism could be improved, then maybe that’s something to look at. So, maybe for me, it’s not great. But maybe you’ve got a sprinter, who is a really fast finisher, but if the race is hard, or you know is over 200K, they just aren’t getting there to the finish, like they’re basically like, they can’t ever deliver that sprint, in my mind, maybe someone like that is a candidate for a bit of that, but if you go crazy with it, then well, they’re also going to lose their fast-twitch, and there, they’re sprint, right? So, I think it’s something that maybe has some validity, but I think I would tend to err on the side of caution and not do it, and feel powerful and strong on the bike, even if maybe I don’t have the highest fat metabolism out there. Then go full ketogenic diet, and then just feel sort of like a wet noodle. I’ve done a bit of it in the past, and honestly, I think I have ridden better and feel better just eating carbs and training harder.


Chris Case  23:57

Let’s turn a corner and talk about the heart of this podcast performance. There hasn’t been a lot of research on how the Ketogenic diet plays out in terms of performance. There’s been some issues with a lot of those studies, perhaps you could fill us in Dr. Noakes, on why that might be and what some of those issues are, and then we can go down the road a little bit further about what findings have found.


Research on the Ketogenic Diet

Dr. Timothy Noakes  24:22

Yeah, indeed. So, it turns out that Steve Phinney was the first guy to do a study on a low carbohydrate diet in 1984, and he took five individuals and two of them improved their performance and two worsened on a long-term diet, it was probably four-to-six-weeks, I can’t recall but it certainly wasn’t a few days. That really gave us an indication that on this diet, if you do it for long enough, some people are going to benefit, and some people may go backward and get worse. We were actually the next people in line to do studies, and we were still using very short duration adaptation because if you are in a bar tree and you don’t have huge funds, it’s very difficult to get people to eat a different diet, which is so completely different to what they’ve eaten before. The idea is you really want to feed them so that then you’re absolutely certain you know what they’re eating, it becomes very difficult to extend the study for more than a week because the cost to you of providing the feed is huge. So, we did some initial studies, and we found benefits. I mean, it was astonishing that I think our first few studies, we showed that there was a benefit. Despite that, I was out there still publicizing the high carbohydrate diet, and I didn’t quite understand that actually, maybe I was still getting it wrong for at least for some people. Now, the reason why there are so many carbohydrate studies because that’s what we were doing, we were doing for every one fat study, we were doing 20 carbohydrate studies, and that was for every laboratory. Why? Because Gatorade was funding this research, not our research, we had somebody else funding it, and they weren’t interested in finding out whether fat makes you exercise better, they wanted to find out whether carbohydrates make you exercise better. So, they had this whole cadre of scientists globally studying carbohydrates, and those people been direct the thinking because they go to conferences, and they talk about the high carbohydrate diets, and how beneficial it is. No one was doing these studies, and I read with Alec and Stephanie, a review, I think two years ago, like we were about 12 studies of a high-fat diet, it was high carbohydrates, there is 12 being reported every month at least, and to try to change that paradigm is extremely difficult. And there have been studies of high-fat diets which have produced a negative outcome, and we wrote one of them, we really did a good study. But again, it was a six days adaptation to a high-fat diet, and what was really interesting was we didn’t try, I think it was a 70 or 100k time trial, and the end outcome was the same, the performance was the same, but unfortunately, we had these people sprint four times during the hundred Ks, and on the second and third sprints they did worse if they’re on the high fat diet, but the other four sprints, they were all the same. So, this fourth showing that you see there’s not enough energy coming from carbohydrates, but that’s a nonsensical conclusion because the fourth sprint was equal in both groups. If they had ran out of energy in the second and third sprint, then the fourth sprint should also have been done, but it wasn’t, and why not? Because they were pacing themselves. And they were getting some information from the body saying, listen, you’ve done something differently in the last six weeks, six days, and we’re not sure if you’re going to get to that fourth sprint, so we’re going to hold you back on the second and third sprint, and then on the fourth sprint, we’re okay because we know it’s the finish. So, but that study was called, The Nail in the Coffin Study for High Fat Diets, Louise Burke wrote that big editorial, she said high-fat diets are a waste of time. The problem was that the study actually didn’t show that, the study showed that the total performance was the same, but it was interpreted as evidence that the diet was not working.


Trevor Connor  28:05

I want to be sensitive here because I know you have a history with Dr. Holley, so we actually had Dr. Holley as a guest a year ago. He had a very strong opinion and brought up some of those recent studies, particularly the one about racewalkers where they put them on a Ketogenic diet, and you did see improvements in their VO2 max, but they found a decrease inefficiency. So ultimately, they didn’t improve in performance.


Trevor Connor  28:35

That’s right. That is absolutely correct. But the problem is that it was a four-week study, and they changed two variables, they changed the height, the intensity of the training went up, it was a training camp. So, they were doing high-intensity training, and they were eating a different. So, obviously, if you are an adapted athlete eating a high carbohydrate diet, and you increase your training, you’re only changing one variable, you’re just training harder. The other people have to cope with more training, heavy training, and a different diet, and they group carbohydrates. So, if anyone’s addicted to sugar and carbohydrates, they’re going to struggle, and they’re going to underperform. So, it was a fabulous study showing one thing, which I’ll talk about just now, but it wasn’t the final test because no athlete that I’ve dealt with, a world-class athlete, would say I’d have to put in four weeks, they say for six, eight weeks, I’m terrible. And then at 14 or 12 or 14 weeks, suddenly things clip in shape, and I started growing better. But what was really interesting in that study was that if you went and looked at the data, they did a racewalk at a competitive speed, before and after adapting to the diet, when they adapted to the diet, almost 100% of energy came from fat. So, here they are walking at race pace, and okay, maybe they couldn’t keep that race pace up for quite as long, but when they were at race pace, they were burning almost 100% fat. So, where is the problem? The fats providing all the energy. The fact that they tail off maybe in the last 10 kilometers could be any reason because performance is not just determined by nutrition. It’s determined by all these other things, and if you feeling lousy, because you haven’t eaten sugar for a week or two weeks, and you’ve got a sugar addiction, and you don’t like the food that you’re eating, and you haven’t yet adapted in the last 10k, why would you push it? You wouldn’t. It’s a great study, but all of our three studies have limitations. The problem I find is that they don’t go out and speak to the athletes and ask the athletes for their opinions, and they don’t go and look at the guys who adapt properly. Why don’t you do a study with the people who fully adapted as we did? And to benefit and we show them as metabolic profile, it is astonishing, their metabolism is quite different, and they’re not metabolically crippled, high carbohydrate athletes are metabolically crippled, because they can only burn carbohydrates, they can’t burn fat at higher rates, and that’s the problem. So, whenever you have to burn fat at a high rate, you can’t do it if you’re not fat adapted. So, I don’t contest that was a great laboratory study, it had major flaws in interpreting it for the real-world situation.


Trevor Connor  31:16

Dr. Holley mentioned that the racewalkers were not pleasant, the ones who were on the high fat diet will do in the training camp, so they were not pleasant people to talk to while they were changing their diet.


Trevor Connor  31:28

Yeah. So, how are they going to perform? How can you do a performance trial under those circumstances? Every day I meet world-class athletes eating a high-fat diet, and they are absolutely happy, they’re incredibly happy, they’re training harder, they’re doing all things right, and they’re very happy. So, the population was wrong. It doesn’t reflect the usual experience of people eating a high-fat diet. I mean, I’ve spoken to John about this, and I said, “You know, your problem is you’re not insulin resistant. I mentioned resistance. That’s the difference.”


Trevor Connor  31:54

Now, have you seen there’s this fairly recent study that came out in New Zealand, it’s a bit of a pilot case study, where they actually put athletes on a ketogenic diet for 10 weeks? Are you familiar with this one?


Trevor Connor  32:07

I have seen the one for four weeks where they showed no change in intense exercise training. There was Philip Maffetone and Paul Larsen, but that one came out like a week ago. I haven’t seen a 10-week study, no.


Trevor Connor  32:19

So, this one was interesting. So, they say endurance athletes, I’m trying to remember specifically what sport, I think these were triathletes. But anyway, it was endurance athletes, and what was fascinating about it, so they went on a ketogenic diet for 10 weeks, they did see a bit of a drop in their performance, but all the athletes lost weight, their body composition improved, several of them saw improvements in health conditions, skin conditions, one of them had, I believe, a prostate issue that seemed to resolve while they were on the diet. What was really fascinating is they did a year follow-up with all these athletes after they had left the study, and they were no longer being controlled. Well, none of them stayed Ketogenic, they all chose to remain high fat, low carbohydrate, and what they said they did was, over time, they slowly brought back a little bit of carbohydrates into their diet, to where they felt they were performing optimally. But like I said, it was still a low carbohydrate, high fat diet, and they all said, we are performing better, we’re recovering better, we feel better, and they just said, I’m never going to go back to a high carbohydrate diet again.


Trevor Connor  33:32

Yeah, in Jeff Verlick’s pasta study, where he took 100 based ultra-distance runners in America, they were exactly the same, these are guys who have eaten a high carbohydrate diet, they then converted and they never went back.


Trevor Connor  33:45



Dr. Timothy Noakes  33:46

They said, I will never go back to that diet, exactly the same finding. And, Trevor, you make a very strong point. You see, the trial doesn’t tell you all those things that you mentioned, the recovery, the loss of weight, those are not measured in these single outcome performances. Let’s say you are eating a junk food diet, which is a high carbohydrate, high processed food diet, and you’re getting infections once every three months, well, that’s going to affect your performance in the long term, or you are getting more injuries or you’re not recovering. That’s not the way you want to be, I’m convinced that you’re going to be much healthier, and the health issue in the long-term is going to be what’s important to your performance. And again, I just make the point that that’s missing in these single studies in the laboratory when you train people for four weeks, and then you test them. You’re not testing what’s really important, what’s really important is how can the people train? How often do they train? How often do they get sick? What about injuries? All those other factors. And I think the judgment is out there, the athletes are saying no, exactly as you said, I recover more quickly.


Trevor Connor  34:52

Now, what about another study where they showed that even though you increased your fat oxidization it seemed to actually damage glycogenolysis. So, for our listeners, your ability to use carbohydrates was reduced, and the point that they were making in that study is in a race situation where you have to do very high intensity, ultimately, no matter how fit you are, no matter how adapted you are, you are going to be relying on carbohydrates. If those processes for breaking down carbohydrates for fuel are downgraded, you’re not going to perform as well.


Trevor Connor  35:29

Interesting because that study wasn’t designed to answer that question, it was designed to answer another question. And then when the other study didn’t come out, they reinterpreted that you have to eat lots, you have to burn lots of carbohydrates to perform. But they’re not looking at athletes, world-class athletes, who are fully fat-adapted, and then you’ll see whether they need carbohydrate or not. What we showed when we looked at fat-adapted athletes, is the markable thing, is that from the first pedal stroke, they were burning fat and huge rates, 1.2 to 5 grams per minute, from the first pedal stroke. And what you do then, is you just burn a little bit of extra carbohydrate, but from the first stroke you are, so you’re consuming carbohydrates. Whereas, if you’re a carbohydrate-adapted athlete, you’ve got the surge of carbohydrate from the first pedal stroke. But unfortunately, after two or three hours, you’ve got less carbohydrate, and now you can’t turn on the fat. So, I could prove exactly the opposite to what John told you. That once you get into the zone where you’ve got less carbohydrate available, you want to be a fat burner, because that’s the only way you’re going to survive. No one’s addressed that question.


Trevor Connor  36:36

So, what about the issue of the high intensity?


Trevor Connor  36:40

Well, you know, I know world-class athletes who are winning Olympic gold medals, who are eating this diet, and they are doing explosive sport, or they swimming 1500 meters, and they suddenly get better when they go on the diet, because they lose weight and they probably become a bit more buoyant or a bit more buoyant, but they become more streamlined. So, to tell me that you can’t do explosive sport without carbohydrates, it’s nonsensical, I don’t see it. These people are tied to the model. They are tied to the model that high carbohydrates are needed for you to do explosive sport. But no one has ever shown that it’s extremely difficult to study fat oxidation when you’re at high-intensity exercise because, for various reasons, which we don’t need to go into, you cannot measure how much fat is being burned when you’re doing high-intensity exercise. So, we all just say well, it’s all carbohydrates because we can’t measure how much fat is being used. There is one experiment done by Paul Laursen, who is very powerful on this high-fat diet when he tested sprinters, and he showed that the best sprinters didn’t burn more carbohydrates than the worst sprinters, they burnt more fat.  That is a novel study, which kind of gets hidden, it’s in the British Journal of Sports Medicine, and is one of the authors. It’s very complex because the methodology is difficult to show how he was measuring fat use, but he’s the only one who’s done it to try to measure how much fat you use, and so because no one studies it, we just sit back and say, well, when you run fast, you’re burning carbohydrate, but we actually don’t know whether that’s true.


Trevor Connor  38:11

But that’s because they’re measuring using RER, and as soon as you get out of any sort of metabolic homeostasis, RER is really not accurate.


Trevor Connor  38:20

Exactly. And the story that you become inefficient, that’s not true. When you burn fat, you’re going to use more oxygen. So, then the scientists will measure that as a lack of running efficiency, but it’s not that, it’s you’re burning fat and you burn fat, you need more oxygen. But then again, you see that, but you mustn’t use too much oxygen, because that’s bad for you, you want to use a little oxygen during exercise, but that’s not true. My point being is if you’re burning carbohydrate, you will use less oxygen. So, you’ll appear to be more efficient, but you’re not. You haven’t suddenly lost your stride or change your mechanics and made you inefficient. That’s not true, that mitochondria just need to use more oxygen when they’re burning fat.


Chris Case  38:58

I’m curious to know why it takes the length of time it does to adapt. And also, how does an athlete know when they have become fully adapted?


Adaption to the Diet

Trevor Connor  39:07

That’s a great question. I think that you only know by your performances. I mean, for me, it was astonishing. After six weeks, my performance has just suddenly improved dramatically with you know, from run to run, it was like I was just going back a decade, every training session. So, you know, I don’t think that elite athletes will notice that. But they will notice that their training intensity goes up, they can now start to train harder, and then the performances will start to go up or back to normal, they’ll normalize, and that takes time, and once that athlete notices that then they’re probably fat-adapted.


Chris Case  39:44

What’s the underlying process of taking those six to eight weeks, is that extremely complex?


Trevor Connor  39:50

Well, yeah, I think that you first need all the mitochondria to change to burn fat, so you’ve got to retool the mitochondria in the muscles, but don’t ever forget the confidence, you know, you’ve got to learn that this is safe. I mean, when I converted the first race, I ran a half marathon, I took carbohydrates with me because I was scared that I’m going to get a hypoglycemic attack. Turns out, because it didn’t happen, but you’ve got to get confidence that this thing is working, because you’ve been brought up to believe that carbohydrates are essential. So, what do you believe? Carbohydrates are essential, and I’m breaking the rules, I can’t be as good as I was, and you have to get confidence that this, in fact, is the difference. So, I think there’s a huge mental training component to it, and that you, you learn that actually, I can do it on this new diet, and I don’t have to hold back.


Trevor Connor  40:42

So, I had an interesting experience, I’ve never actually gone to the Ketogenic level, but obviously, I eat a much lower carbohydrate, higher fat diet. But I also do a lot of partial fasting, because of all the research I’ve read on the health benefits of that. I remember the year I started, that would usually have Tuesday as a day when I wouldn’t eat, or just have something small in the morning, and then it wouldn’t eat the rest of the day, and we had a training race here in Boulder that I would go to. I remember the first time I did that, I think I lasted 15 minutes, I just couldn’t hang on. I kept doing it every Tuesday, and it took about six-to-eight-weeks, but what shocked me was by about the eight-week point, I would actually go and do three sets of my high-intensity intervals, then connect up with the group, and do the whole training race with them, and the training race was about an hour and a half long, so this was two and a half hours of high-intensity work, and I was doing that pretty much not having eaten very much that day, and the only thing I would take with me on the ride was a bottle of water.


Trevor Connor  41:45

And you see that we haven’t studied that. That’s the problem. But everyone, there are so many people telling me that, we have to start thinking that there’s something in this. Let’s make it quite straight, we were the first people to produce gels for use during marathon running, and we developed this product. I just regret, we both regret that we ever made it. So, because we convinced runners that you can’t go five yards without needing more carbohydrates. Whereas now we are learning you can go hundreds of kilometers without needing to eat, but to get people to believe that and understand that it’s going to take a long, long time.


Trevor Connor  41:51

I mean, I’ll tell you, I mentioned this in a previous podcast where I talked about my background with the Paleo Diet. When I was racing full-time, I was classic sports nutrition, I was trying to get my 800 grams of carbohydrates per day, and I always tell the story, I was getting sick all the time.


Dr. Timothy Noakes  42:51



Trevor Connor  42:52

When I went on the Paleo Diet, I was 39 about to turn 40 and had another year of racing professionally, it was one of my best years.


Trevor Connor  43:02

Yeah. That happens so often, you just can’t ignore it. People like Dave Scott, win six IRONMAN in the 1970s, he converted three years ago to the high-fat diet. He read my book, The Real Meal Revolution. He converted he said, “Oh my gosh, I got it wrong all those years.” And he simply says, “I will not allow my IRONMAN triathletes to train on a high carbohydrate diet full stop.” He says you can do it for five or six years, but then you collapse, and here is a guy who’s done both. But the most remarkable story, which I have to share with you, was in 1984, Paula Newby-Fraser comes from Zimbabwe to South Africa, I meet her, we had long discussions about training, I helped her a little bit with her training. She goes to the one IRONMAN, she does extremely well, she decides okay, I’m going to become a professional athlete. She goes to San Diego, and at that time, she reads Steve Phinney’s book on the high fat intake, and she phones me from America, and says, “I’ve just read Steve Phinney’s article. He says we should eat more fat. What do you think?” I said, “Paula, I think that’s a great idea.” And I say that, even when I am promoting high carbohydrate diets. So, she adopts the high-fat diet, low carbohydrate, I did not tell her to restrict carbohydrate, but she did, she chose to. She wins eight IRONMAN, sorry, 28 IRONMAN and she wins the Kona World Championship eight times. When she comes to South Africa, she seeks me out because we’ve had this long friendship, she says, “The most important single piece of advice I’ve ever had in my whole athletic career was what you told me.” So, I said, “Paula, what did I tell you?” She said, “To eat a high-fat diet.” I said, “But Paula, I never told you to cut the carbs.” She said, “Well, I did it anyway and it worked.”


Chris Case  44:55

I think it’s worth having you point out why people can go for such long distances once they’re keto-adapted? And talk about the number of kilocalories stored in your body as fat versus carbohydrates that are stored, and how that works out when you’ve fully keto-adapted, could you explain that?


Trevor Connor  45:13

So, what people have to understand that humans evolved to have very small capacity to store carbohydrates, and I don’t know why that is, but there has to be a reason. Part of it is when you store carbohydrate, you store water. So, we can talk about, let’s say, 600 grams of carbohydrates, and each gram provides four calories. So, that’s 2400 calories, 2.4 thousand calories as in carbohydrate. But even a lean athlete, probably got 40,000 calories in fat, and the size is an enormous difference. So, if you can just burn the fat, you can go for probably four days of running. Whereas on carbohydrates, you’re going to make about two hours. So, what we’ve done and what already said with John Holley, because he was one of the key researchers that we worked with, we did experiments, which I now understand, we were trying to stop athletes burning any fat. So, we were loading them with carbohydrates before they exercise and then loading them up during, and the consequences are going to be very little fat during the exercise, and they burned many carbohydrates. But we never studied beyond two hours, because that was kind of what you can do in a laboratory. But once those people go beyond two hours, and they’re getting depleted of their carbohydrates, they’ve now got to get another source. So, if they read in the gauge raid website, they’ll say you need 100 grams of carbohydrate every hour in the IRONMAN to keep you going. But we know athletes to get through the Ironman, even world-class athletes, eating 20 or 30 grams of carbohydrate, and 120 grams of carbohydrate, or maybe 160 grams of carbohydrate during the race and they do perfectly well. What we proven is that it’s possible if you can access your fats, that it can take you through these events, because there is just so much fat available. And again, that’s how humans evolved. We evolved to be fat burners not to be carbohydrate burners, because as Trevor said, we had only seasonal exposure to carbohydrates, carbohydrate was not there available all the time. But fat was if you could catch fat animals there was fat available.


Trevor Connor  47:24

So, it’s actually something I want to ask you about that you might not have an answer for. But you know, as you said, because of the nature of the research there, there aren’t a ton of studies on this yet. However, we’re seeing lots of top tier cycling teams that are starting to promote the Ketogenic diet, and we have athletes that are top cyclists who at least say they’re on a Ketogenic diet. What do you think is driving that? Is it simply just experimentation?


Professional Athletes Promoting the Ketogenic Diet

Trevor Connor  47:52

I think in cycling weight is such a big issue, as you know. I know Chris Froome wrote a lovely story, because Chris Froome’s wife is from Cape Town, says she’s from my town, and Chris tells a story that he came second in the tour Spain. That was when his breakthrough year was, and he lost six kilos, and he arrived in Cape Town and his girlfriend said, “You look great dreadful, what happened.” He says, “Well, I just came second in the Tour of Spain.” She goes, “I’m not talking about that, I’m saying your weight, you’ve lost so much weight.” He said, “I just started starving myself, and the more I starved, the better I did because of the weight loss.” And then she said, “You’ve got to eat a high protein diet,” because I think she has some nutritional background, well, of course, there’s no such thing as a high protein diet, it’ll be a high fat, low carbohydrate diet. And he adopted that, and then the key is he’s clearly insulin resistant, she said he’s got a sugar addiction, loves sugar. And he couldn’t regulate his weight on a high carbohydrate diet. But now, in the training season, he will restrict his carbohydrates, but during the competition, as you said, he will have more carbohydrates on the day that he does the difficult stages. But it is not the 800 to the kilogram of carbohydrate that they used to eat, it’s now in the range you’re talking about, 200 grams, up to 200 grams, and to me, that is still a very low, that’s still a low carbohydrate diet, particularly doing five or six hours cycling a day.


Trevor Connor  49:12

That’s what I was going to ask you about. So, people at the highest level, you know, I still have a hard time believing that they could perform at their best, racing as much as they are, as intense as the race are being on a pure ketogenic diet. Imagine they’re more like me, a high fat, low carbohydrate, but not quite to the ketogenic level, and it sounds like you would agree with that.


Trevor Connor  49:36

Absolutely. You know, I think to me, I can’t see why you’d ever need to eat more than 200 grams of carbohydrate. I’ll tell you another thing we found in our experiments, that if your carbohydrate adapted and we’d make you do exercise for a couple of hours, you still burn carbohydrates for the rest of the day. So, you are eating more carbohydrates than you need, but if you’re fat-adapted, you do burn quite not carbohydrate during the exercise, but after which you switch off the carbohydrates and you burn fat. So, the carbohydrate, you only need the carbohydrate for the exercise, you don’t need it for the rest of the day. So, the people who are eating more than 300 grams of carbs a day, or maybe burning 250 grams during the exercise, the other carbohydrate they’re burning during the rest of the day, which you don’t need to. So, there’s some cutoff value of how much carbohydrate each of us need, I don’t think it’s much above 200 grams. For most people, 200 grams would be a low carbohydrate diet, they would think that they are really restricting carbohydrates quite severely.


Trevor Connor  50:32

Yeah, and we talked about that before, if you are going to consume those simple carbohydrates, do it during the exercise, and then get away from that on the rest of the day. So, to kind of summarize all this, it sounds like the issue with a lot of the contrary research is simply the fact that they, the people they were studying weren’t fully adapted, keto-adapted, or fat-adapted, and so they were often researching them at that, that low point when their body’s adjusting to this completely different diet. And you see different results in those rare studies, where they take people who are fully adapted, but it also sounds like the research that really needs to happen is taking those fully adapted people and seeing how they’re able to do high-intensity work.


Trevor Connor  51:19

And yeah, and we’ve done that. One guy came to us who the leading triathlete of his age, over 40 in South Africa, and he said, you know, “I can do the IRONMAN, and I don’t need any carbohydrates or excess carbohydrate during the Ironman. But I want to know, if I do shorter distance races, I seem to go a bit slower in that half IRONMAN, I think get about two carbs.” So, we tested him because he was such an amazing athlete, he could produce the same performances. We showed that carbohydrate ingestion impaired is on men performance, the longer performance is 100Ks, but over 20Ks, they improved his performance. So, taking carbohydrates helped him in the short distance, but had a slightly negative effect on the on 100Ks or further cycling. So, I think that’s probably the truth, there is a distance at which a little bit of extra carbohydrate will help you. But once you get into pure longer distances now it’s not going to help, and there’s no biological reason why it should, because as long as your muscles can burn fat, they can provide all the energy you need.


The Physical and Mental Process of Going Keto

Chris Case  52:22

I think what I’d like to hear from you now is okay, this all sounds incredibly fascinating. I want to try this myself, how do I do it? What do I not do? What do I do? But let’s talk about the physical and mental process of going Keto.


Trevor Connor  52:40

Yeah, I think that the best advice I can give us the way I did it, you cut out all sugar, that’s the first thing you really look for. And you cut out cereals and grains because I think those are the two toxic components of the diet. So, bread has to go, and cereal for breakfast has to go. And you start eating high fat, high protein breakfast, which are usually cooked, and eggs need to be a big component of that, and like whatever else you like, fish, yogurt, but it must obviously be full cream, no carbohydrate yogurt. So, you start eating those foods and there are great lists in our book, Real Meal Revolution, we have a fantastic green list, which gives you all the foods that you can eat. But I don’t think you want to go from 500 grams of carbohydrate a day to 100. I’ve had lots of athletes who come and said I can’t get out of bed in the morning on 100 grams a day. So, you need to cut slowly. So, maybe you started 250 grams. So, you need to start counting the grams of carbohydrates and understand which foods have got lots of carbohydrates and which don’t. So, you slowly narrow your foods down by cutting out those higher carbohydrate foods. So, you’re left with a range of foods that you can eat, which will give you 250 grams of carbohydrates a day, and you stick there for a couple of weeks, and then you go to and let’s say your performance shouldn’t be impaired at that level, then you go down to 200, and then you go down to 150, and then maybe lower if you want to. But I think it really depends on how insulin resistant you are, and if you’re not insulin resistant and your insulin sensitive, there is no need for you to go below 250 grams, 200 grams, because you don’t get the same effects from those 200 grams that I get, they make me diabetic, but for insulin sensitive, it’s fine. So, the pressure is not to reduce it below 200 grams, and you’d only want to go lower if you felt that your performance could be improved. I can tell you, it’ll be really difficult for us to do studies to show that all athletes benefit by being at 50 grams compared to 200 grams, there must be so much individual variability, some will do very well on 25 and some will be on 200, and you know what? There is no study that can tell you what’s going to work for you. You have to get up and test it. That’s the other point I say about the laboratory studies, that’s the limitation. They tell you what the average response was for that group of studies students or people who are being studied, for you, it is what you do. So, I would say you get down to 250-200, and then you reduce and see what the benefits are. And by this time, you need to start looking at your HBO and seeing your fasting insulin, and you see if they are elevated, well, then unfortunate to have to go lower. But if they are normal, then that’s fine. You can stop it that carbohydrate intake. So, those are the guidelines, and then you have to learn to cook as well, the other thing to diet properly, you need to be able to cook.


Trevor Connor  55:40

But what I like hearing you say is you are not taking the approach of you must be ketogenic to get the gains, or you’re wasting your time, you’re saying for some people, they might get benefits from that, and it might be worth experimenting with it, but the key thing here is to get the carbohydrates down and be on a high fat, low carbohydrate diet.


Trevor Connor  56:01

Yeah, exactly. What you define as the low carbohydrate is for each of us to discover, and you have to find out how many grams make a difference. And, you know, I’ve worked with guys who’ve lost 150 kilograms, that’s 260 pounds.


Trevor Connor  56:14



Dr. Timothy Noakes  56:16

And I can tell you, if they eat 50, or sorry, they eat 50 grams of carbs, the weight starts coming going up again, they have to stick at 25. The cut-offs are remarkable, for each of us there’s a carbohydrate intake that will either make you right or wrong. I’m convinced that if I’d eaten 50, or 60 grams of carbs a day for the last seven years, I wouldn’t be in remission now. I had to go to the extremes, I had to go to 25 grams, and over seven years, then you get the change. So, my point is that for each of us, there’s a cutoff value of carbohydrates that’s beneficial.


Chris Case  56:47

Is there a way to get a general idea of what that quantity of carbohydrates should be based on your body type, your age, or is it much more specific and individualized than that?


Dr. Timothy Noakes  57:01

Yeah, this is really personalized medicine. The beauty is that you can answer the question for yourself, you know, you don’t have to go to medical laboratory to find out. So, you’ll soon see whether you’re training, as Trevor spoke about his own experiences, that he found that initially, it was terrible, but then he slowly improved, and eventually was performing much better on this particular diet than he would have believed possible. So, I think that’s the beauty. You’ve just got to use yourself as an experiment. We are each an experiment of one, and you just must judge, I guess from your response to the diet, as to what’s happening.


Trevor Connor  57:37

I don’t think I’ve ever been purely ketogenic, but I’ve gone lower, I’ve gone higher. And it’s, as you said, experimentation, see where your energies levels at, where your performance is at, and I just find I feel my healthiest, my energy levels are my best, I’m performing my best.


Trevor Connor  57:52

Yeah, that’s exactly right. So, that’s the point. The body will tell you how much carbohydrate it needs. But you just have to be sensitive and listen carefully to what it’s telling you. You must always try the opposite experiment. So, let’s say you thought that 125 is ideal, we’ll go down to 25 and see what happens, and you’ll see your performance is awful, and go up to 250, you’ll see it’s not better, or it could be worse. And then you know, I have mentioned Bruce Fordyce, you know, he was really interesting. He said that people run a marathon 10 times and they say, I ran this marathon 10 times, but you run it once but you just repeated the same errors 10 times, that’s the message you have to get across.


Chris Case  58:36

Another concern I guess I have seen from people out there is if I want to go into full ketosis, and I get there, and then oh, you know, I have this urge and I can’t help myself and I have a cheat day or a cheat meal. Does that throw everything off? Does it take a while to go back into ketosis? Or is it a simple blip and not a big concern?


Cheat Days

Trevor Connor  58:59

I’m glad to tell you it’s not a big concern, were studying that question right at this moment. If you’re really properly fat-adapted, and you increase your carbohydrate intake for one meal, it makes no difference. Basically, you just store the carbohydrate, and you burn it off the next with high-intensity exercise. On the other hand, if your carbohydrate adapted and you eat carbohydrate, you respond differently, you immediately burn the carbohydrate, because you have to because your body simply got too much carbohydrate on board. So, cheat meal is no problem at all. What the problem is if you do two cheat days together, it takes about two days to get back to normal. So, then if you’re doing two cheat days a week, it means you got four days where you’re eating a high carb diet, essentially, and you’ve got three days on the high-fat diet, and that’s not going to help. So, the cheat day cheat meal is fantastic. If you extend it to more than a meal, then you’ve got a problem because then you’re gonna have to take a day to come back to normal.


Chris Case  59:59

So, your recommendation is to reap the full benefits of it, It has to be a permanent thing, a consistent thing with the occasional cheat, and you’ll be fine and you’ll get the most benefit out of that way.


Trevor Connor  1:00:13

Yeah. And the other reason why you don’t cheat is because if you’ve got a sugar addiction, and most of us, and I had a terrible sugar addiction and still have, but I don’t eat sugar that’s not apparent. So, I’m a sugarholic in rehabilitation.


Chris Case  1:00:26



Dr. Timothy Noakes  1:00:28

And, many athletes are like that. And to get off it, you can’t eat sugar. So, I don’t mind you cheating on healthy carbs, but please don’t eat processed sugars and sweets, that’s a disaster because that’s going to kick you back into searching for sugar, and you’re just activating the addiction again, and that you don’t want to do, the one slice of chocolate, one cube of chocolate becomes a slab of chocolate every day, and you won’t come back from that.


Chris Case  1:01:01

You are making me hungry talking about chocolate, I’ll just let you know.


Supplementing With Ketone Bodies

Trevor Connor  1:01:04

So, one last quick question. What’s your thought on some people are now supplementing with ketone bodies.


Trevor Connor  1:01:11

Brianna Stubbs is a great friend of mine, she’s the lady who’s done most of the research in that area. She did the work at Oxford, and she is now in San Francisco, developing with working with a company to start marketing the product. I went to see her in San Francisco, and the reason I tell you this is because there’s something about it, which I don’t know. And at that time, my glucose was still running high at about 6.5, and she gave me a thimble full of about, I don’t know, a couple of ml of the ketones, and my glucose dropped unbelievably. Within about 30 minutes, it was astonishing, the green from five to 5.5. It was like taking a medicine. There is no meds and I know other than insulin, which can drop your glucose dramatically. M ketones went from .3 to 3 in 20 minutes. So, the product they are producing has an incredible effect. But I never get to three ketones unless I’ve run a marathon and not eating. So, it was a huge effect on me. And so, it is metabolically it’s very, very powerful. I think it is still early days to say whether it’s going to affect performance. If it affects performance, it’s going to be due through the brain. And in other ways that ketones would act like glucose, you know, if you take glucose on your mouth, your performance goes up, and it can’t be as it’s you are metabolizing because it has some direct link to the brain. I would not look for the effects in a metabolic effect in the muscle because the muscles got so much energy anyway and in 30 minutes, you are not going to run out of fuel so why should keep that make a difference? And I think that is going to be an interesting area. But it’s clear to me that these ketones are huge, very powerful.


Trevor Connor  1:02:48

Full disclosure here, Chris and I weren’t able to get an interview with a pro doing the keto diet in time for this podcast to go live, but we’re always happy to talk with World Tour Rider, Sepp Kuss. Sepp’s team, Lotto NL Jumbo, works with another famous researcher in nutritional science, Dr. Asker Jeukendrup. Dr. Jeukendrup has researched another side of this high low carbohydrate debate called, Nutritional Periodization, basically you have times when you do both. Sepp shares his firsthand impressions of this periodized nutrition.


Sepp Kuss: Periodized Training

Sepp Kuss  1:03:21

I wouldn’t say we do full-on Keto diet, but it’s definitely training high, training low, which are kind of the new titles.


Chris Case  1:03:32

Yeah, explain that a little bit more.


Sepp Kuss  1:03:33

So, training high is training with large amounts of muscle glycogen. So, for example, that would be eating a really big breakfast of high carb, and then training immediately after, and then that trains your gastric emptying and your body’s ability to process those carbs, and the maximum is around 60 grams an hour. On the other hand, the training low is training with low muscle glycogen, and that can be fasted rides training with reduced carbohydrate intake per hour, training two sessions a day, things like that. So, we definitely do both, we’ve got a really good nutritionist, Asker Jeukendrup.


Chris Case  1:04:30

Is he your,


Sepp Kuss  1:04:32



Chris Case  1:04:33

I didn’t realize.


Sepp Kuss  1:04:33

And him and Nancy, yeah, they’re super knowledgeable about different ways to train high, train low, and when to do it because I think,


Training High and Low

Chris Case  1:04:43

Yeah, when are when are you doing this? Throughout the season?


Sepp Kuss  1:04:47

Yeah, throughout the season. I think for the training low it is not good to do it really during the season.


Chris Case  1:04:54



Sepp Kuss  1:04:54

But yeah, a lot in the preseason, offseason at training low and yeah, and then the more race heavy part of the season, training high, because you need to, a lot of people’s bodies cannot process that 60 grams of carbs an hour. So, you need to train your gut.


Chris Case  1:05:13

Yeah, I know. I know Asker is big into almost thinking like that the gut and the stomach are part of what needs to be trained in an athlete, because it is essential. Tell me about the experience, how has it been going? How does it feel when you’re on these high and low schemes?


Sepp Kuss  1:05:34

Yeah, for the high, I think it’s is generally what I have done in the past, so it’s not too new to me. If you’re doing it on your own, it’s yeah, I think it’s the safest. Training high, I was I guess surprised by the amount that you actually need to eat, like to actually get 60 grams of carbs an hour, which is a lot. Yeah, a lot of food.


Chris Case  1:05:58

Yeah, right.


Sepp Kuss  1:06:00

Training low. So, for me personally, I’m not really a fat burner. You know, I can create a lot of lactate, which is good in certain races, like accelerations, and a lot of good sprinters or classics riders have a high, yeah, VLA Max, they can create a lot of lactate, but they’re also burning that,


Chris Case  1:06:24

Using it as fuel.


Sepp Kuss  1:06:25

Yeah, and it comes at a better price. So, for guys like me, and it’s important to also do the training low, and for me, that’s a big shock to my system, because it’s like, oh, no breakfast?


Chris Case  1:06:40

Do you feel like you’re going to bonk?


Sepp Kuss  1:06:42

Yeah, it feels like a bonk. Just bad moods. Real hangry. I think it’s only good if you do it consistent, you know, it’s not like one training load session is going to improve your fat metabolism or anything. But yeah, you know, you have to go not all in, but you have to do it in a sustainable way for a while to see any benefits.


Chris Case  1:07:12

Are you seeing perceptible improvements in, this would be an improvement in probably your long-term sustainable endurance?


Sepp Kuss  1:07:23

Yeah, yeah. I think. Yeah, in general, I feel like I have maybe better endurance than I did, but I can’t say if it’s because of the, you know, training low.


Trevor Connor  1:07:36

Let’s get back to the interview, and Dr. Noakes a summary of what he’s recommending.


Dr. Timothy Noakes  1:07:40

So, my issue if your insulin resistant, like myself, and you need high carbohydrate diets, your performance starts to dip quite quickly, in my impression, maybe within five or six years, you start to put on weight and you struggled to perform as well as you did when you were eating a less carbohydrates. And, and you now are setting yourself up for diabetes, and that’s what really worries me, that’s when we look at the world’s best athletes, the Kenyans, and you see them running on very high carbohydrate diets, 75% carbohydrates, and then everyone says, “Well, that’s what I must be.” Well, the answer is they, they probably different metabolically, and they probably highly insulin sensitive, and maybe to be the world’s best marathon runner, or the world’s best Olympic cyclist at Olympic distance cycling, you have to be incredibly insulin sensitive and able to burn carbohydrates at high rates. Or if you want to be the world’s best four-minute mile, or you have a world-record-holding the mile, maybe you have to be incredibly insensitive. But that’s, that’s that population, and it’s a tiny, tiny proportion of the population, the rest of us, and certainly, the majority of recreational athletes, if we force them to eat high carbohydrate diets, we put them on the path to diabetes. We have to realize you can go to these marathons or go to the cycling races, and the top cyclists are all lean, but just go a little bit back an hour behind and see how fat the people are, and those people should not be eating carbohydrates, because they are insulin resistant and the carbohydrates are killing them, and all the exercise in the world can’t reverse insulin resistance. The only way you can cope with insulin resistance is to eat a low carbohydrate diet. So, one of the problems I have is that many of the people advocating high carbohydrate diets are not medical doctors, and they don’t understand the consequences of getting 10s of thousands of recreational athletes who are insulin resistant, eating carbohydrates, you are killing them. So, in summary, if you’re a world-class, elite athlete, eat your carbohydrates as long as you’re insulin sensitive, but for the rest of us, for the recreational athletes, you will do your health, a lot of it, good. If you simply cut the carbohydrates and eat more fat, lose their weight, and be much healthier as a consequence.


Chris Case  1:09:54

So, Dr. Noakes, you’re on the clock, you’ve got one minute, what do people most need to understand about the Ketogenic Diet from your point of view?


Dr. Timothy Noakes Takeaway Message

Dr. Timothy Noakes  1:10:03

What most athletes need to know is that most of us are recreational athletes, and recreational athletes can do all he needs to do, or she needs to do on a high-fat diet. The only exceptions are the elite athletes, who clearly may need carbohydrates to perform optimally in events lasting, let’s say, from a minute up to two or three hours, and they may benefit by eating more carbohydrates. The reason I stress this is recreational athletes are much more likely to be insulin resistant, and overweight, and if you’re insulin resistant, you are heading for diabetes if you eat a high carbohydrate diet. So, learn from my experience, I ate a high carbohydrate diet for 33 years, and I could not outrun the bad effects of the bad diet. So, eat a very healthy diet with lots of healthy fats, healthy proteins, and minimal carbohydrates, and if you’re insulin resistant, you will be healthy for your life, and you’ll avoid all these chronic diseases and lifestyles.


Chris Case  1:10:58



Trevor Connor  1:11:00

My turn?


Chris Case  1:11:00

Yeah, I’m not sure I have one, because I’m such a novice at all this, but Trevor I know you know your nutrition.


Trevor Connor  1:11:06

I’m just going to expand on that in a point I’ve made before which is the remember your sources, just because you are eating the right ratio of fat to carbohydrates and protein, doesn’t mean that you are eating a healthy diet, especially if you’re trying to be high fat by eating lots of bacon and butter and avoiding vegetables. So, a couple of very quick tips there. You still should be eating fruits and vegetables. Just pick your sources. So, vegetables, your cruciferous vegetables, and things like Bok choy, Brussel sprouts, kale, broccoli, they’re all low carbohydrates. Likewise, your low carbohydrate fruits are your berries and focus on your healthier fats. So, a great one is coconut oil, which does have a lot of saturated fats, but it’s medium-chain triglycerides, which have been shown to have a lot of health benefits. So, pick your sources, you still want to be eating healthy foods.


Chris Case  1:12:05

I think I would close with don’t latch on to trends, and just because you hear Team Sky is doing it doesn’t mean that you have to follow their regime or cut things immediately and down to extreme levels. Like Dr. Noakes was saying, this is experimentation you have to go through with yourself and it’s about finding a sweet spot, sometimes that’s really low and sometimes that’s not as low. You have to listen to your body like you do with so many things in sports, and this is no different and nutrition is so important that you really have to tailor it to yourself.


Chris Case  1:12:42

That was another episode of Fast Talk. As always, we love your feedback. Email us at Subscribe to Fast Talk on iTunes, Stitcher, SoundCloud, and Google Play, be sure to leave us a rating and a comment. While you’re there, check out our sister podcast, VeloNews podcast, which covers news about the week in cycling. Become a fan of Fast Talk on Facebook at, and on Twitter Fast Talk is a joint production between VeloNews and Connor Coaching. The thoughts and opinions expressed on Fast Talk are those of the individual. For Dr. Noakes, Joe Dombroski, Sepp Kuss, Coach Trevor Connor, I’m Chris Case, thanks for listening.