Tuesday, 1 February 2011

Nutrition and Fat Facts!

I've been meaning to write a blog entry about a subject which I am very passionate about right now...


As athletes, I think we all realise that nutrition can play a huge role in performance. This becomes even more relevant in ultra endurance events like Ironman and beyond.

Think about it... We can all race at certain (comparatively fast) speeds over Sprint and Olympic distance, but we have to slow things right down for Ironman. In fact, I'm sure we'd all agree that none of us are going "that fast" in real terms during an Ironman and most people's Ironman marathon pace is well short of what they could maintain for a straight marathon.

So what is the limiting factor?

We've done the training. In IM we are not racing nearly as quickly as we are capable of in other distances and we've trained our bodies to cope with the various physical demands we subject our them to on race-day (impact forces, climate etc). Having met and addressed all these issues, one limiting factor remains, and its a biggy....


Ironically, it's probably the most important and maybe even the most overlooked - certainly when viewed as part of your training regime.

The rate at which you can fuel your muscles will have a greater impact on ultra endurance performance than almost anything else (assuming you've done the training!!).

We have a huge supply of energy which we carry around as fat, both beneath the skin (subcutaneous fat) and within the muscle known as "Intramuscular fat" or "Intramuscular triglycerides" (IMTG). The energy contained within these supplies is abundant - even in the leanest of athletes. "Training" your body to metabolise fat for energy at a high rate is the secret to unlocking your Ironman potential.

The master of this science was surely Mark Allen who, legend has it, could run at 6:00 per mile pace for an Ironman marathon metabolising fats alone!

A well designed nutrition plan can turn you from a "sugar junky" into a "fat burning machine" - essential for Ironman performance. At the same time it will also improve recovery, increase training quality, regulate energy levels, boost immune health and reduce disease risk (to name but a few additional benefits).

Worth saying here that by "Nutrition Plan" I mean a way of eating FOR LIFE. Every day, during training, after training as well as specific feeding during races. It's not something you "dip into" now and again. And it's certainly not something you should only give consideration to on race day. It's a commitment for life - but not one that needs to be all that difficult, or unpleasant, to achieve - quite the opposite in fact!

It's also worth saying, that the points I want to make, while perhaps directed towards "sporty people" are just as valid for the general population - maybe even more so! They just need to be tailored to suit your own energy needs.

I must also quickly mention my sources. Most of what I am now learning is a direct result of my involvement with Martin MacDonald, a Performance Nutritionist from Loughborough University. Martin has bucked the "main stream" in his search for the real facts regards performance nutrition. It is Martin's mission to debunk the many nutritional myths that are so often touted by businesses selling crack-pot diets, the media, Government Agencies and even the medical profession! Martin's results, with many high profile clients and elite sports people, speak for themselves and I consider myself very lucky to be in his care. I have gladly become one of his foot soldiers in this battle against nutritional bunkum and hypocrisy!

I can highly recommend Martin's Site. There is an abundance of information, Martin's own blog and a brilliant and active forum...

It's all cutting edge, and it's all free - Martin just wants people to know the truth!

Mac Nutrition

So, lets start with some basics....

Your body needs a certain amount of energy to function and we get this energy from the food we eat (and stuff we drink).

Even at rest, you need energy to "power" all your body's vital functions and it's organs. This includes breathing, circulating blood, adjusting hormone levels, growth, repairing cells and brain function - all pretty important stuff wouldn't you say! This amount of energy an individual needs every 24 hours, just to do this, AND NOTHING ELSE, is known as their "Basal Metabolic Rate" (BMR).

You can get a good estimate for yours here...

BMR calculator

The importance of fuelling these "life sustaining systems" is the precise reason why you would be very ill advised to ever reduce your calorie intake below your BMR. Don't do it!

Your body needs this energy - it can't do without it! In simple terms, it's like expecting your car to run without fuel - it won't and nor will you without adequate calories to meet you BMR requirements.

Sadly this is precisely what is advised by so many fad diets. Shakes, soups, bars whatever - they are not clever...it's simple calorie restriction (and profiteering). Worse still, these very low calorie levels are often achieved by a dramatic reduction in dietary fat intake (as fat is very energy dense) and are inevitably sub optimal in terms of "nutritional value" to boot.

Thankfully, our bodies have evolved over millenia to cope with calorie restriction or "famine" as some might like to call it. "Beta Oxidation" is the process by which the body can utilise it's own fat stores to produce "ketones" which the body can, in turn, use for fuel. The body goes into state known as "Ketosis" - a phrase you may well have heard about in relation to "Atkins" type diets (low cal / low carb).

There is no dispute, beta oxidation happens and it can lead to people losing large amounts of weight. Unfortunately the body is designed to hold on to it's fat stores - they are very precious! The body would rather "slow things down" first before resorting to beta oxidation. So your BMR slows - you now need fewer calories at rest and some of the "less essential" bodily functions start to shut down. Hair, skin, nails, hormones, energy levels and brain function all suffer.

You know the look - I call it "low cal chic". Pale, dry, papery skin, scraggy hair, broken nails, sunken eyes and diarrhea? And that's just the less serious stuff! Is it any wonder the body starts to fall apart when it needs maybe 1500 calories "at rest" and some crash diets restrict calorie intake to ridiculous levels like 500 cals per day (and still expect you to go about your daily activities and a trip to the gym!)

Another point worth mentioning here is Insulin. We've all heard of it. It's what regulates how your body deals with carbs and fats (more on this later). In simple terms - a healthy metabolism responds to very small amounts of Insulin - in other words, it is "sensitive" to Insulin - this is a good thing. Trouble is, a lifetime of poor nutrition and eating refined carbs can completely screw your body's sensitivity to Insulin. More Insulin is required to achieve the desired carb regulating effects which in turn increases the bodies fat storing potential. Individuals who's metabolism is screwed (or sub optimal) will struggle to loose weight through simple calorie restriction alone.

This effect was illustrated by a study I read recently, where lab rats were "overfed" and their Insulin sensitivity manipulated through the administration of Insulin injections. Not unsurprisingly, these rats became very, very fat. The feeding was then stopped completely and the rats were essentially starved. The Insulin injections, however, continued. One would imagine that the rats, in the absence of calories, would "tap into" their now abundant fat stores right?


They simply starved to death and just died very, very fat rats. Big old fat stores still very much in tact.

Anyway, I've wondered off track....Where were we?

Oh yes....so if you want to loose weight (fat mass) reduce calories by all means - but nothing lower than your BMR please!

So we understand the energy needs to meet BMR - but what about everything else? We all walk about, climb stairs, (some more than others), some have physical jobs etc etc. These activities also require energy. The energy demands of these activities, combined with the energy demands to fuel your BMR create your "Non-exercise activity thermogenesis" (NEAT). This is quite simply, the energy needed for all physical activities other than "sporting like exercise".

So lets say everything is tickety boo and you simply want to "maintain" your weight, you should consume enough calories to meet your "NEAT"..... pretty neat hey?

We'll talk about training in just a moment, but for the time being, lets stay focused on your "NEAT needs".

So where should these calories come from and does it really matter? Well yes it most certainly does! These calories should come from a variety of sources. For the purpose of obtaining calories, the ones that matter are Carbohydrates, Fats and Proteins. Lets just make one thing clear. It's ok to eat ALL these types of food. But what is certainly up for debate is the relative proportion of each food group.

Recommendations dating back to the 70's suggest a shift towards a carbohydrate rich (60%) low fat (20%) diet. It was suggested (and still is in more recent recommendations) that this is a far healthier way of eating and would lead to reduced levels of obesity and reduced rates of killer diseases and Type II Diabetes.

In reality, over the last 30 years, the opposite has happened. Even though a shift toward this type of diet has occurred, obesity, heart disease, and diabetes are all on the up. In fact statistics took a marked swing skywards since general populations started increasing intake of (mostly refined) carbohydrates. These dietary recommendations are completely unsubstantiated. They are not based on scientific fact and there is precious little (if any) evidence to support them.

Ever wondered if it makes sense to advise a shift away from fats and proteins, both essential for life, to carbohydrates, which the body has no biological need for whatsoever? I don't want to get too bogged down in specifics, but this video (all 5 parts) is well worth a watch and should leave you in no doubt that we have been sold a pup by Governments and food advisory groups.

Big Fat Fiasco part 1
Big Fat Fiasco part 2
Big Fat Fiasco part 3
Big Fat Fiasco part 4
Big Fat Fiasco part 5

To cut to the chase - A better ratio of food groups might be in the order of 30% Carbs, 40% Fat, 30% Protein. The figure that will jump out here for most people is 40% Fat. Please understand. Eating fat does not make you fat! Eating refined (high GI) carbs does!

Starting with fat, forget what you've heard about fat (particularly saturated fat) and heart disease. Again - there is a complete lack of evidence to support the link (Watch the videos above if you haven't already). The fats to avoid like the plague are those that man has "meddled" with (Man Made Trans Fats are the worst!).

Your fat intake should come from oily fish, nuts and seeds, and dairy (whole milk please, preferably un-homogenised). For cooking, baking or spreading you can't beat Coconut Oil (Virgin) or good old fashioned butter. If you must use a vegetable oil - stick with olive. Never use vegetable oils, margarine etc.

Butter and coconut oil etc are natural "food" products with nutritional value. Margarine is not natural and it's not a food. It has no real nutritional value. It's chemically closer to a lubricant than anything you should be eating! I plan to write a blog entry dedicated to fats (my new best friend) so I'll stop there on fats for the time being.

Proteins are best derived from animal sources though high quality protein can be derived by combining non-animal sources such as nuts, beans and pulses etc. It is however much more difficult to obtain a "full" protein with all the essential amino acids from non animal protein. As for meat,quality really does make a big difference. Words to look for are "organic", "free range" and "grass fed". If the animals were fed crap while they were alive, you'll just end up sharing in their misfortune!

Finally carbs. They are not evil - well not completely any way. They have their place in a healthy diet - particularly the diet of an athlete. As mentioned previously, around 30% of your NEAT needs can be met with carbs, but try and keep the sources low GI (below 55) as these foods have less of an affect on blood sugar and therefore Insulin (the fat storage hormone!).

Brown rice, Bular Wheat, Spelt or Rye Flour, whole meal pasta (cooked aldente) quinoa are all good "staples". Fruit is also very much on the menu, but best to stick to berries, plumbs, cherries, black grapes, pears and apples.

Also think about when you eat carbs. This is key. Consume them if you are training in the next few hours or after training to re-fuel but hold the carbs if you are not training for a while. For me this is midday, when my lunch is carb free (but high protein / fat).

Finally fill up on green leafy vegetables as often as you can - every meal if possible, though I accept that Broccoli for breakfast might be pretty hard to stomach for some!

The other point where carbs enter the equation is during long training sessions and post training. Here it's just a simple case of meeting the needs of the particular session. 1g of carbs per kg body weight per hour is a good place to start, but again, there is no reason why some of these energy needs can't be met with fats.

Re-Fuelling after training should occur as soon as possible. Ideally within 20 minutes. Your carbs at this point should be HIGH GI (contrary to everything I've been saying). Combining high GI carbs like Dextrose with a high quality whey protein supplement will create an insulin "spike" (in this instance desirable) to really kick start the recovery process and maximise training adaptation. I'll go into detail on this another time! Just a word or warning - immediately post training fats are to be avoided. Particularly if you are consuming high GI carbs to spike Insulin. For that reason, biscuits, cakes and chocolate should definitely be avoided at this time!

I kinda glossed over weight loss earlier, as this was not meant to be the focus of the blog entry. But to finish, if you want to loose weight, calorie reduction is required. However, NEVER reduce intake below your BMR. Keep the proportions of food "type" the same. If anything, reduce carbs, but never fats. Then it's a simple case of aiming for something in the order of a 500 kcal energy deficit per day, to affect a healthy rate of weight loss of around 1-2lb per week.

I hope I've inspired you all to look a little bit at your diets. I'll leave you with a personal observation.

Since working with Martin, my diet and calorie intake have been optimised to regulate energy levels, fuel my training sessions and shed body fat. I'll be the first to admit, that I'm naturally a bit of a bean pole, but I did have a few stubborn kg to get down to my ideal racing weight of 70kg. (it's even harder to loose weight when you don't have much to loose!).

My carb intake has been reduced and my dietary fat intake has increased by 200% yet the 2kg of excess body fat has gone! I'm running and biking faster than ever and have yet to catch a cold this winter. Oh yes and my hair has never looked so glossy!

Happy days!


  1. What a pleasant read! Great info, that I`ll definitely be looking into. Read it at lunch time while eating a totally verbotten Subway Chicken Teriyaki sarny :)

  2. Great blog writing Dunc!

    I am loving reading Martin's blogs and have enjoyed this one too. Every time I read one I feel like I am becoming more educated and empowered about Nutrition. I have started trying to educate a few friends but there is so much focus on 'low fat' that's quite difficult to make them see sense!

    Keep up the good work :-)

  3. A really interesting post Duncan, the BFF videos are a real eye opener. I'll definitely be making some changes to my diet which has been really high carbs and very little fat for a long time. Pass the blue milk please!

  4. Very interesting read...although I'm following the high carb/low fat regime just now, after seeing a sports nutritional last month. So far, so good. I'm eating loads more than I used to and feel lighter and more energise. I'll let you know when my hair falls out :-)

  5. Thanks for your comments Debbie. Great that you have an "open mind". I too followed a high carb, low fat diet and did "ok" off it (several successfull Ironman triathlons etc etc).

    I think some people are just lucky - they are naturally lean and have healthy fat cells. I count myself as one of those people as I have never had a real "problem" with weight, despite high carb intake - maybe you are the same?

    However, since switching to a high fat, high protein and "controlled" low GI carb intake, I have seen improvements to my physique, health and sports performance that I just can't deny.

    Do keep popping back to my blog from time to time - I wish you luck with your diet and racing.


  6. I stumbled across this blog accidentally and must say its been a great read, and most enlightening! After watching the BFF videos in particular I made the decision to try the sort of diet you are suggesting, after having been on a fairly high carb low fat type diet. I found the results spoke for themselves, however I quickly ran out of energy in the evenings during exercise, and also found it quite difficult to keep it low carb and get enough calories in. Do you have any example days of what you would eat on a typical training day. I'd like to carry on and give this diet a proper shot, as I think the science is very sound!


  7. Hey Thomas - that's great news. Glad you enjoyed the read and have got some good results with a higher fat diet.

    To your points, you really shouldn't be having any problem getting the calories in - particularly if you have upped your fat intake.

    Your problem with low energy levels could be low glycogen? It is important for athletes to include carbohydrate after training - particularly if it's been a hard session. You must make sure your muscle and liver glycogen is restored post training to avoid chronic depletion.

    What you will find as you become more and more fat adapted (this takes months to feel the deeper effects) you will be drawing LESS on muscle glycogen during your training sessions and more on body fat and intramuscular fats. This means your glycogen stores are preserved for the much higher intensity efforts (as nature intended). You suffer LESS depletion and any depletion incurred can then be managed through fat and protein intake - with quite low carb intakes (gluconeogenesis).

    For me - I always have a post training shake including say 50-60g carbs and then I include some good carbs in my next meal say oats if it's breakfast or sweet potato / quinoa / white rice if it's supper.

    My lunches are almost completely carb free as I train morning and evening - with just a recovery or weights session at lunch time.

    Breakfast is also carb free (eggs + Meat) if I have not trained beforehand.

    Hope this helps.