Sunday, February 1, 2015

Low Carb High Fat Nutrition #1 - The One-Eyed Man is King

I don't think it's that I'm particularly perceptive with positive trends in the world around me, it usually takes a while for my sensors to pick up the winds of change. I think I'm just lucky to be surrounded by some intelligent, inquisitive people. By now though, I've uncovered so much muck on the deceptions in the fields of health and sport that some might get the impression I'm constantly digging around for conspiracies. The reality is that I'm becoming more and more aware that we shouldn't expect that anyone is looking out for our well-being; we have to take that responsibility on board ourselves and READ!

Though I've long been aware of the extremely limited value of carbohydrates in a healthy diet, about 3 months ago I decided to test out the theory as championed by an increasing number of highly respected thinkers in my field of interest - endurance sports, and see what living on a low-carb, high-fat diet was all about. After this little time I already know I've found something significant.

In the process I have been made aware that if we follow popular opinion and public health recommendations we are really never likely to understand anything about nutrition for the rest of our lives, and we'll be fighting unnecessarily against health problems caused purely by the improper fueling of our bodies. I mean this is so WRONG!

For this first article though, I will concentrate on my primary agenda when investigating the science of nutrition, which was to become a more effective athlete. The wider issues I will deal with later.


In the traditional understanding of our energy systems, we have 2 sources of fuel that we can use for movement, and which we can store in our bodies: fat and glucose. The fat is stored in our adipose tissue to an (almost) unlimited degree, and a small amount of glucose is stored as glycogen in our muscles and liver. At lower intensities of activity it is generally assumed that our bodies will run on the fat-burning energy system, metabolizing fatty acids out of our adipose tissue and into the blood stream to the working cells, and that as the intensity increases, more of the glycogen in the muscles is needed.

Well that's the "conventional wisdom". In reality our bodies will use blood sugar (glucose) in preference over anything else. Easy fuel. In the modern super-refined world, most of us have little chance of ever metabolizing most of the fat we're constantly storing as we're perpetually switching between surges of sugar and insulin, the hormone which regulates our blood sugar and which massively inhibits fat metabolism: our body's ability to use it's stored fat. It's an either-or situation. As long as your blood carries sugar your fat remains in storage.

Fat is extremely dense in energy and so even a lean person has enough stores for several marathons, whereas even a trained athlete with maximized glycogen storage capabilities can only keep going at a top sustainable pace for a maximum of around 2 hours. Though we can top-up the glycogen in our muscles on the go with sugar (glucose) - the idea behind sports drinks and gels - we can’t fully replenish the stores until we stop and recover, so we will have to compromise on the pace if we want to keep going.

Endurance athletes learn to manage both pace and glycogen replacement in order to maximize performance. We become obsessed with loading our bodies with carbs before events to maximize glycogen stores. This has always seemed a kind of sad testament to the efficacy of the human body, this incredible machine that we’ve inherited, so I was always a bit suspicious that this wasn’t somehow embracing the whole picture adequately.

What if you could train your body to metabolize fat more efficiently so that you would rely much less on that tiny store of glycogen? I had often heard this concept discussed but it never really seemed to tie in with the “conventional wisdom”. Recently I’d heard of some athletes who are doing this with considerable success. The final straw was when I heard that Tim Noakes, author of The Lore of Running, and one of the most respected and meticulously well-researched sports scientists on the planet, had started championing a high-fat, low-carb diet. This is a man who had devoted an entire chapter in his aforementioned meisterwerk to the value of carbohydrates. I looked into his current activities and found he was part of a group of scientists and dietitians represented on the website Real Meal Revolution where they have created a diet plan they call the Banting Diet. I read the mission statements, watched the videos, listened to the arguments and quickly realised that these guys were onto something that had changed their lives.


If you vastly reduce the amount of carbohydrates you consume - the Banting recommendation is no more than 5% of daily consumption - your body adapts to run in a state of Ketosis. In the absence of sugar, and consequently insulin, your fat metabolism is at it’s most efficient, and those functions that are used to running on sugar (the brain most importantly) will run on ketones which are produced in the liver. This state is apparently the natural state our hunter-gatherer bodies functioned in for the past 2 million years, until we invented agriculture and started eating grain, so it’s not like we need a lot of training! In the absence of carbohydrates of course, you will need to consume more of your daily calorific needs from protein and fat, and it’s here that the science starts to get really interesting.

My scientific reference point is Gary Taubes’ amazing book Good Calories Bad Calories. Taubes is a scientific investigative journalist who has spent 5 years amassing an incredible body of knowledge for this book, collected from research done in every field of science relating to diet and disease. Most of this research in the separate fields has been done with a jaw-dropping apparent disregard for each other’s work, and consequently little valuable cross-referencing.

In this book Taubes exposes some shocking evidence of bogus science that has led to the stunning levels of misinformation of public health institutions, that have consequently increased the incidence of diabetes and most of the other Diseases of Civlisation to epidemic proportions. I will devote plenty more writing about this aspect of his research in future posts, but for now I want to concentrate on the relevance to athletic performance, which is how I came to it.

The fundamental message of the book is that it is carbohydrate, and our body’s production of insulin that is at the root of all of these diseases, and at a most basic level, has severely compromised our ability to metabolize fat for fuel. The other side of the misinformation dilemma is that the widely-accepted fear of cholesterol, and consequently saturated fat, is the result not only of bogus research, but of a massive over-simplification of the understanding of the role of cholesterol in our bodies, and how this relates to heart-disease. The fats that are good for us are precisely the ones that have been demonized for most of the past 50 years. Suffice to say that I now eat a lot of bacon, eggs and butter, but without the bread. I will elaborate later.


This is very much a work in progress. The plan was to cut out all grain and sugar from the diet and see if I could train my body to run, at every intensity level, on fat. My diet wouldn't really include much more protein than it did, but it would be far higher in good fats (saturated, short-chain fatty acids, and monounstaturates), and contain no more than 5% carbohydrate, none of which comes from grain or anything refined. After 3 months I can say with emphatic assurance that it works.

The missing link is still what, and how much I need to consume immediately before, during and after exercise in order to keep functioning optimally. The available information is patchy and often contradictory. There is plenty of literature about high-fat low-carb nutrition, but relatively little real testing done on how it relates to athletic performance, and what adaptations are needed.. Carbs are just easy because they digest so fast, but fat, and especially protein, doesn't. So this will be a major study on my part of how my body responds.

The first week is tough. My first few rides or runs were pretty pathetic, but even if you discount the reduction in athletic performance, the cravings for fast and easy fuel take a few days to die down. Obviously I kept everything at an easy pace, and relatively short duration, and fueled myself during workouts on water only.

After a couple of weeks I started to be able to push the pace or duration a little. About a month in I could actually do some quite hard but short sessions, but what I was more pleased with was that I could go for much longer at a moderate-to-high pace. Sub threshold. By this time, most carbohydrate looked like cardboard to me - just not proper food.

After a little more than a month on the diet I did a ride of 600km in 4 days, and though I allowed myself a reasonable amount of carbs during the rides themselves, I didn’t feel I needed as much as before, didn't use any carbs in recovery, and didn’t seem to have any limit to my stamina. I also didn’t feel I lacked speed or strength.

Over the past few weeks I have pushed the envelope in various ways. I have done 3 back-to-back days of hard effort consuming only water, where the last day was actually the best; I have done plenty of rides of up to 4-5 hours with a short stop for tea and boiled eggs; and I have done rides of up to 7 hours where I took just a minimum amount of carbohydrate when I felt I needed it.

By this time a few other changes are noticeable.

  1. I have lost a significant amount of weight. I am 182cm, and now weigh around 72kg, whereas even racing Ironman 10+ years ago I could never get below 75-76kg
  2. Though I am thinner than I’ve been for most of my adult life, I don’t look gaunt or feel malnourished in any way.
  3. I don’t get hungry like I used to. I now recognize those feelings as a craving. In fact I have to make a point of eating so that I don’t lose muscle mass.
  4. My skin and hair are definitely looking more healthy. In fact my hair colour has got noticeably darker.
  5. I have more energy than ever before. I wake up energized, and even after a long tough day will still have the energy to go for an evening run.
  6. Interestingly I had previously thought that I had, over the years, developed a mild lactose intolerance, but since being carb-free I have no reaction at all and can freely indulge again. Also my tolerance for toxins like strong coffee has become much greater since starting the diet.

The point is, that I feel better than I have ever felt. I can keep cycling for hours without any diminishing of strength. I get very hungry at times, but it is never accompanied by that feeling of running out of fuel. Just hunger.

There’s still a long way to go in this study process. I still have to answer many questions on muscle recovery, glycogen use and replacement, what’s best to eat during training/races etc. I still feel I’m nowhere near my new-found potential. I haven’t even got into the full swing of training again yet, but I will continue to make notes and talk about it here.

You can also expect some furious tirades on the public health institutions that refuse to review or update their bogus scientific data in articles to come.

And being 5 kilos lighter, I’m much faster up the hills :)

Much more to this space!


  1. I'm guessing it's only suitable for long, relatively low intensity efforts. One test might be to see how you feel in a bike race where you’re burning energy at a much higher rate. I think I mentioned to you that top ironman triathletes have to be burning almost entirely fat on the 180km bike leg to spare glycogen needed to run such fast marathons afterwards.

    1. Long-term report is that this is definitely the holy grail for not only athletes, but anyone who cares about their health. As far as energy for top-level performance goes, there's nothing missing. The only issue might be to replace glycogen during, or quickly after, a hard session or race, but the jury's still out on that one.