Alternate Approach to Fueling the Endurance Athlete

Our last post we discussed carbohydrate (CHO) as a primary fuel source and factors that need to be considered. In this post we want to shed light on an alternative approach to fueling as an endurance athlete and how it stacks up against traditional methods.

With the growing body of literature investigating the current ‘traditional and text book’ endurance based nutrition, I wanted to take sometime to highlight some of the newer evidence along with an alternate strategy. I am not saying this is a strategy for everyone, as in so many areas of our sport (e.g. training and nutrition) there is so much individual variance. However, with my clinical and personal experience if done correctly, I have found an approach that works for the majority of clients and is something I highly suggest you consider and test out, not only from a performance standpoint but for your overall health as well.

 

Background/ Training Nutrition

Before talking about race nutrition (particularly Ironman) you must first understand training nutrition. The science has made some significant developments in recent years and I want to identify what these recent changes are and then compare them to traditional nutritional methods and try help you identify which is the best approach for you!

 

What is Traditional/Textbook Endurance Nutrition?

This nutritional method is based around the intake of CHO and the ability to load (before) and continually replenish CHO stores during exercise.

 

What does this mean?

Challenge Roth 2014

Typically our bodies can only use ~1g of CHO / kg of Body Weight / Hour. We are constantly told that to perform at a high level or merely ‘last the distance’ in any endurance event requires us to be fueled solely by CHO. Go to any endurance event or even give “Ironman Nutrition” a quick google and you will see this is still a common thought. Ironman itself even puts on a pre-race dinner “Pasta Party” based around this concept, with the intention of CHO loading (I pre-ate before attending).

But sport science is a new science so we are always learning and older practices (nutritional or other) are being re-investigated and newer methods are always being developed and tested. In the case of nutrition for ultra events the science is evolving and initially these challenge all my previous beliefs, creating a lot of confusion (even for me, someone who has studied sport science).  But, in taking a step back I was able to analyse from a non-bias standpoint and used a bit of logic to allow me to see the potential of this new nutritional strategy.

 

So, what was being suggested? 

A flipping of the traditional method on it head! Out with the CHO during training and in with the fat! With CHO so ingrained in our culture not only as athletes but also in general day to day life, it can be challenging.

There are plenty of methods that now utilise this approach with some variance within them: High Fat Low Carb (HFLC), Very Low Carb and High Fat (VLCHF), Paleo, Ketogenic, Aktins or Modified Akins. Despite their differences (mainly in their name choice) they all work on a similar premise, that is to reduce CHO used during low- moderate intensity (sparing our very very limited body CHO stores for those rare times when we need to sprint finish) and increasing our efficiency at using fat as a fuel source. Some of the diets listed above are a bit more extreme than others. So which one is best? Again it comes down to you and what suits YOU best.

 

My goal: My focus is always on efficiency and maximising performance both physical and mental. Therefore, I put the high fat strategy to the test against Ironman, with the intention of be able to utilise fat a primary fuel source throughout the race.

 

Fat Adapted Athlete or Metabolically flexible

Put simply you have the ability to use fat as a fuel during exercise and this saves your bodies limited CHO stores (~500-600g even when you eat a lot of CHO in your diet). This shift allows you to move away from a limited and finite fuel source to one that is unlimited!!!!!

At the lower exercise intensities required during an Ironman (we are exercising for 8-17 hours) the increased use of our fat stores may mean less frequent refueling and less reliance on external fueling methods (now no stress now if you drop that one gel out on course). Another added benefit of using your fat stores is enhanced fat loss, great for body composition.

Your health is also improved by shifting to a ‘high good fat’ diet. This is due to the fact that when you use fat as a fuel you do not create the inflammatory response that we see with CHO. Less inflammation is great for supporting a healthy body (Let’s talk Science: High Carbohydrate Vs High Fat)

The ‘traditional’ CHO method would argue that fat use in exercise limits your ability to perform at the top end of your chosen sport (endurance and even anaerobic based power athletes). But the recent research has debunked that argument. Some of the best triathletes would consider themselves to be high fat/ low carb and they are winning events at an amateur and professional level.

 

Put in to practice: Proof is in the pudding

 

Pro Athletes: It is hard to say exactly who is and who isn’t but those to the best of my knowledge are listed below. Along with being pro athletes a lot of them are also coaches themselves as well.

Simon Cochrane: 1st Rotorua & Karapiro Half Ironman, 3rd place IM Japan, 3rd IM Taiwan, 3rd IM Philippines. IM New Zealand PB 8:21

Jan van Berkel: 1st Ironman Switzerland (in record breaking time), 5th 2018 IM Texas (7.48.40); 4th 2018 IM New Zealand

Tim Reed: 1st 2018 IM 70.3 Vietnam, 2nd  2017 IM 70.3 Asia Pacific Championships, Western Sydney, 2nd IM Australia, Port Macquarie

Dougal Allan: 1st 2018 Motatapu Xterra, 1st 2018 Redbull Defiance, 2nd 2017 IM Western, Australia

Kyle Buckingham: 1st 2018 IM  African Championships

 

Coaches / Athletes: Who are renowned for the High fat approach to training

Dan Plews (Coaching Service: Plew & Prof): 1st 2018 Age grouper in IM New Zealand – 8:35

Bevan Mckinnon (Coaching Service: Fitter): 1st 2016 Kona IM in Age group World Championships  

 

This does not mean it will work for everyone!! I just wanted to highlight that this is a strategy being utilised by top athletes, showing that its does not reduce your performance, in fact it may have the opposite effect. These are just some of the top athletes well known for this approach but there are plenty more and it is a strategy that is continually growing in popularity as science proves the validity of this nutritional strategy in performance and health measures.

 

How does a Carbohydrate Athlete match up to a Fat Adapted Athlete

I wanted to keep it simple as I know this topic it can become overwhelming to most. Listed below are a comparison of the two strategies.

Key Things to consider:

Below are some key factors to consider before jumping into this approach and often the biggest mistakes I see athletes make.

 

  • CHO Tolerance: Carbohydrate tolerances or insulin sensitivity (ability to produce adequate insulin when required, to ensure efficient uptake of carbohydrate) will vary from person to person. There is no one size fits all macro breakdown there are just guidelines!

 

  • A-Type Personality: The biggest mistake I see especially in the A-Type personality world of triathlon is athletes going to extreme to quick. Just like physical training this shift in fuel substrate should be a gradual adaptation. I highly suggest easing into it, you should never be suffering (eg starving) if so you are pushing your limits too much! However, if done correctly the benefits to your health, performance and longevity will be profound!

 

  • Female Athlete: Females must also be cautious in adapting this approach as you traditionally require more CHO and must consider the impact of your menstrual cycle and design your intake accordingly. For this reason there doesn’t seem to be too many Pro female Ironman athletes currently, I have heard that Melissa Hauschildt (1st Female 2018 IM Texas – North American Championships) is high fat athlete but that has not been confirmed. I think this is something we will see more as we learn how to better cater the approach to the specific demands female body. As quoted by Stacey Sims: “Women are not small men!”

 

  • Train Low Race High: Once fat adapted, athletes to often approach their racing the same as there training void of or minimal CHO. If you want to optimise your performance you buffer your CHO stores so that you can utilise both CHO and fat substrates to their full potential. Although,  this has been recently shown to be especially important in more competitive and elite athletes than those working at ;lower intensities 

 

Take home message:

No detrimental effect in performance, less need for refueling, fat loss and faster recovery, it sounds pretty good to me!

I will say it again that as with any nutritional approach there is no one size fits all approach, you must find what works for you! Sometimes that means some long term self experimenting. Take it gradually don’t go all out and end up with Keto Flu.

 

References:

Burke, L. M., & Hawley, J. A. (2002). Effects of short-term fat adaptation on metabolism and performance of prolonged exercise. Medicine & Science in Sports & Exercise, (2). https://doi.org/10.1249/01.MSS.0000027690.61338.38

Burke, L. M., Wood, C., Pyne, D. B., Telford, D. R., & Saunders, P. U. (2005). Effect of carbohydrate intake on half-marathon performance of well-trained runners. International Journal of Sport Nutrition and Exercise Metabolism, 15(6), 573–589.

Campbell, C., Prince, D., Braun, M., Applegate, E., & Casazza, G. A. (2008). Carbohydrate-supplement form and exercise performance. International Journal of Sport Nutrition and Exercise Metabolism, 18(2), 179–190.

Carey, A. L., Yeo, W. K., Carey, A. L., Burke, L., Spriet, L. L., & Hawley, J. A. (2011). Fat adaptation in well-trained athletes : Effects on cell metabolism REVIEW / SYNTHE Fat adaptation in well-trained athletes : effects on cell metabolism. Applied Physiology Nutrition and Metabolism, (April 2016). https://doi.org/10.1139/H10-089

Cipryan, L., Plews, D. J., Ferretti, A., Maffetone, P. B., & Laursen, P. B. (2018). Effects of a 4-week very low-carbohydrate diet on high-intensity interval training responses. Journal of Sports Science and Medicine, 17(April), 259–267.

Harvey, C. J. C., Schofield, G. M., & Williden, M. (2018). The use of nutritional supplements to induce ketosis and reduce symptoms associated with keto-induction : a narrative review. PeerJ. https://doi.org/10.7717/peerj.4488

Havemann, L., West, S. J., Goedecke, J. H., Macdonald, I. A., Gibson, A. S. C., Noakes, T. D., … Fat, E. V. L. (2018). Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. Journal of Applied Physiology, 194–202. https://doi.org/10.1152/japplphysiol.00813.2005.

Jentjens, R. L. P. G., & Jeukendrup, A. E. (2005). High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. The British Journal of Nutrition, 93(4), 485–492.

Jeukendrup, A. E., & Wallis, G. A. (2005). Measurement of Substrate Oxidation During Exercise by Means of Gas Exchange Measurements. Int J Sports Med, 26(S 1), S28–S37. https://doi.org/10.1055/s-2004-830512

Jeukendrup, A. (2008). Carbohydrate feeding during exercise. European Journal of Sport Science (Vol. 8). https://doi.org/10.1080/17461390801918971

Malatesta, D., Brun, J.-F., Astorino, T. A., Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising maximal fat oxidation during exercise: determinants and normative values. Frontiers in Physiology, 9(599). https://doi.org/10.3389/fphys.2018.00599

Maunder, E., Kilding, A. E., & Plews, D. J. (2018). Substrate Metabolism During Ironman Triathlon: Different Horses on the Same Courses. Sports Medicine. https://doi.org/10.1007/s40279-018-0938-9

Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising Maximal Fat Oxidation During Exercise : Determinants and Normative Values. Frontiers in Physiology, 9(May), 1–13. https://doi.org/10.3389/fphys.2018.00599

Newman, J. C., & Verdin, E. (2014). Ketone bodies as signaling metabolites. Trends in Endocrinology & Metabolism, 25(1), 42–52. https://doi.org/10.1016/j.tem.2013.09.002

Oliveira, E. P. De, & Burini, R. C. (2014). Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress. Nutrients, 4191–4199. https://doi.org/10.3390/nu6104191

Painelli, V. D. S., Nicastro, H., & Jr, A. H. L. (2010). Carbohydrate mouth rinse : does it improve endurance exercise performance ? Nutrition Journal, 2–5.

Paoli, A., Grimaldi, K., Agostino, D. D., Cenci, L., Moro, T., Bianco, A., & Palma, A. (2012). Ketogenic diet does not affect strength performance in elite artistic gymnasts. Journal of the International Society of Sports Nutrition, 1–9.

Peters, S. J., Amand, T. A. S. T., Howlett, R. A., Heigenhauser, G. J. F., Spriet, L. L., Ln, O., … Lawrence, L. (1998). Human skeletal muscle pyruvate dehydrogenase kinase activity increases after a low-carbohydrate diet. The American Physiological Society, (8).

Peters, S. J., Harris, R. A., Wu, P., Pehleman, T. L., Heigenhauser, G. J. F., Spriet, L. L., … Spriet, L. L. (2018). Human skeletal muscle PDH kinase activity and isoform expression during a 3-day high-fat / low-carbohydrate diet. American Journal of Physiology-Endocrinology and Metabolism, 1, 1151–1158.

Peters, S. J., & Leblanc, P. J. (2004). Nutrition & Metabolism Metabolic aspects of low carbohydrate diets and exercise. Nutrition & Metabolism 2004, 8, 1–8. https://doi.org/10.1186/1743-7075-1-7

Pfeiffer, B., Stellingwerff, T., Hodgson, A. B., Randell, R., Res, P., & Jeukendrup, A. E. (2012). Nutritional Intake and Gastrointestinal Problems during Competitive Endurance Events. Medical Science in Sports and Exercise, (7), 344–351. https://doi.org/10.1249/MSS.0b013e31822dc809

Pfeiffer, B., Stellingwerff, T., Zaltas, E., & Jeukendrup, A. E. (2010). CHO oxidation from a CHO gel compared with a drink during exercise. Medicine and Science in Sports and Exercise, 42(11), 2038–2045. https://doi.org/10.1249/MSS.0b013e3181e0efe6

Prado, E., Roberto, D. O., & Burini, C. (2014). Gastrointestinal Complaints During Exercise : Prevalence , Etiology , and Nutritional Recommendations. Sports Medicine, 44, 79–85. https://doi.org/10.1007/s40279-014-0153-2

Stellingwerff, T., Spriet, L. L., Watt, M. J., Kimber, N. E., Hargreaves, M., Hawley, J. A., … Pdh, D. (2018). Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. American Journal of Physiology-Endocrinology and Metabolism, 380–388. https://doi.org/10.1152/ajpendo.00268.2005.

Stuempfle, K. J., Hoffman, M. D., & Hew-butler, T. (2013). Association of Gastrointestinal Distress in Ultramarathoners with Race Diet Association of Gastrointestinal Distress in Ultramarathoners with Race. International Journal of Sport Nutrition and Exercise Metabolism, 2, 103–109.

Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., … Phinney, S. D. (2015). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, 65(3), 100–110. https://doi.org/10.1016/j.metabol.2015.10.028

Volek, J. S., Noakes, T., & Phinney, S. D. (2015). Rethinking fat as a fuel for endurance exercise. European Journal of Sport Science, 15(1), 13–20.

Zinn, C., Wood, M., Williden, M., Chatterton, S., & Maunder, E. (2017). Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes. Journal of the International Society of Sports Nutrition, 1–9. https://doi.org/10.1186/s12970-017-0180-0

Zügel, D. (2016). Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon. International Journal of Sport Nutrition and Exercise Metabolism.

 

Effect of Carbohydrate & Athletic Potential

Are Carbohydrates Maximising your Athletic Potential?

Now that we have touched on some of the effects of carbohydrate on general health, let’s progress into carbohydrate as a primary fuel source in athletic events. In this article we will have a look at the literature and discuss how you can optimise your performance through the fourth discipline of triathlon, aka “fuel and nutrition”.

 

Limited Storage Capacity

The leading limitation of carbohydrate (CHO) as a fuel is it’s storage capacity (500-600 grams) and the need for continually refueling to maintain these stores. The rate of CHO absorption can be minimally manipulated and may depend on your CHO sources used. Interestingly the maximal CHO absorption capacity that has been achieved is 1.8g of CHO / min  (4,6). But CHO storage (500-600g) is dwarfed by fat storage (5+) kg even in a very lean individual). This is a phenomenal difference, this benefit alone should be enough to spike any endurance athletes attention. I say endurance athlete because any sport under 1-1.5 hr can store enough CHO to supply energy for their chosen activity, and in this case using fat as a fuel may not be the best strategy. But it is endurance athletes who regularly exceed this time threshold and who can really benefit from utilising fat as a fuel. However, this is only one benefit and there is a growing body of scientific evidence suggesting a wide range of other benefits that I will discuss and will benefit majority of athletes regardless of  the sporting event.

Source of Carbohydrate: Is it important?

Many athletes fail to recognise or understand the difference between different types of CHO. CHO can be divided into two main divisions, the rapidly oxidized CHO (up to ~60 g/hr or 1 g/min; include: glucose, maltose, sucrose, maltodextrin and amylopectin starch) and slower oxidized CHO (up to ~30 g/hr or 0.5 g/min; include: fructose, galactose, isomaltulose, trehalose and amylose). The reason for different oxidation rates is due to the different CHO sources using different CHO transporters in the gut and increasing the amount going from the gut to the blood. Therefore, ingestion of multiple transportable (glucose + fructose) CHO vs. single transportable CHO enhances exogenous  (external from body  eg food, supplements etc) CHO oxidation and increases performance (9)

Gels & Long distance Triathlon

To the best of my knowledge Zügel, (2016) (15), is the only study that has specifically looked at the administration of gels in long distance triathlon. A number of studies have looked at other shorter disciplines comparing gels to a liquid source of CHO with varied results. (1,2,12) Long distance triathlon possess several unique conditions compared to these sports such as, the inability to consume fuel while in the swim and possibly the change in body position across the three disciplines over the day that may impair gastric emptying (nutrition moving from the stomach into the intestine to be absorbed) and increase GI distress(11). In a study of long distance triathletes (15) the results suggested that gels compared to liquid CHO caused no difference in performance. But the study did show that people that consumed gels had an increase GI distress.

Gastrointestinal  Distress

As a CHO based athlete the need for continuous refueling is essential part of training and racing. But what we see is that sometimes these high and regular fuel intakes are closely related to Gastrointestinal (GI) distress. The ability to tap into endogenous fuel (produced internally in body) sources over exogenous fuel (external from body  eg food, supplements etc) would be extremely advantageous in minimising/preventing GI distress.

When consuming exogenous CHO, multiple transporters have been shown to not only increases CHO absorption but also aid in reducing GI complaints. Therefore, it is advantageous to consume CHO from multiple transporters, from a performance standpoint along with minimising GI distress. O’Brien, & Rowlands (2011) (8) concluded that a 0.8 ratio (0.8 fructose + 1.0 maltodextrin) presented the least amount of GI distress. If you are someone who is particular sensitive, this is an important consideration when selecting you personal fueling strategy.

Gut Traininability

Higher absorption of CHO is associated with less residual CHO in the intestine and it could prevent GI distress, an obvious potential strategy would be to increase absorptive capacity of the gut through training the gut to tolerate higher levels of CHO (15). However, more research is required.

Carbohydrate Mouth Rinsing

In recent years there has been emerging research around the ergogenic (performance enhancing) action via the central nervous system. It has been demonstrated that CHO mouth rinsing presents performance enhancing benefits in events 60 min or less. There is limited research in endurance based events (60 min+). But this could offer athletes the ability to bypass or reduce GI distress associated with CHO refueling, making it especially useful in the run segment of triathlon due to increase in GI distress seen with high impact and jaring activity. However, as an emerging area of research more depth is required to identify the exact mechanisms at play and to provide guidance on best practice for a strategy like this.

Metabolic flexibility

When it comes to optimising you your fourth discipline “Nutrition”, you need to look at what your current training load, the duration of the event you are training for and what is the best practice nutrition that will allow you to achieve your goals. For longer events (training 12 + hours a week and events greater than 2 hours in duration) the best possible nutritional approach would be to seek and attain metabolic flexibility.

So what is Metabolic flexibility:

When I say metabolic flexibility I am referring to your ability to adapt your fuel utilisation to meet the energy demands of the exercise stress which you are putting yourself through. For long distance events, low-moderate exercise intensity your body will be most efficient when utilizing fat as a fuel. You want to be an efficient fat burning machine, this will allow you spare your limited muscle glycogen stores so that when you need to use them for that all out maximal sprint finish, your body can adapt and change fuel sources from fat to CHO to meet energy demands.

By not aiming to achieve metabolic flexibility you are limiting your performance potential by not maximising your ability to utilise alternative fuel sources. I would even go as far to argue metabolic flexibility is one of the most performance enhancing strategies you can train to promote overall health, weight maintenance, longevity and sporting performance.

As a metabolically flexible athlete having the ability to shift from CHO to Fat as a primary fuel source (almost exclusively, very minimal CHO) when they are resting, sleeping and moving slowly is highly beneficial. One of the most beneficial components is that you are reserving your limited CHO to be utilised in higher intensity activities like sprinting. Therefore a metabolically flexible athlete or fat adapted athlete has the ability to maximise their substrate utilization and ensure optimal efficiency for endurance events. It is like fueling your body with diesel (fat) & high octane fuel (CHO), giving you the efficiency and endurance of the diesel coupled with the ability to tap into your high octane fuel when you need surge or increase intensity. Compared to fueling with one or the other on its own, this approach would seemingly limit your capacity to shift between the two when required.

To achieve this you need to look beyond the limited CHO and train your body to utilise other limitless fuel sources like fat alongside CHO to truly maximise your potential. In our next post we will compare the metabolically flexible fat adapted athlete vs the traditional high CHO based athlete.

 

References:

  1. Burke, L. M., Wood, C., Pyne, D. B., Telford, D. R., & Saunders, P. U. (2005). Effect of carbohydrate intake on half-marathon performance of well-trained runners. International Journal of Sport Nutrition and Exercise Metabolism, 15(6), 573–589.
  2. Campbell, C., Prince, D., Braun, M., Applegate, E., & Casazza, G. A. (2008). Carbohydrate-supplement form and exercise performance. International Journal of Sport Nutrition and Exercise Metabolism, 18(2), 179–190.
  3. Cipryan, L., Plews, D. J., Ferretti, A., Maffetone, P. B., & Laursen, P. B. (2018). Effects of a 4-week very low-carbohydrate diet on high-intensity interval training responses. Journal of Sports Science and Medicine, 17(April), 259–267.
  4. Jentjens, R. L. P. G., & Jeukendrup, A. E. (2005). High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. The British Journal of Nutrition, 93(4), 485–492.
  5. Jeukendrup, A. (2008). Carbohydrate feeding during exercise. European Journal of Sport Science (Vol. 8). https://doi.org/10.1080/17461390801918971
  6. Jeukendrup, A. E., & Wallis, G. A. (2005). Measurement of Substrate Oxidation During Exercise by Means of Gas Exchange Measurements. Int J Sports Med, 26(S 1), S28–S37. https://doi.org/10.1055/s-2004-830512
  7. Malatesta, D., Brun, J.-F., Astorino, T. A., Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising maximal fat oxidation during exercise: determinants and normative values. Frontiers in Physiology, 9(599). https://doi.org/10.3389/fphys.2018.00599
  8. O’Brien W.J., Rowlands D.S. Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance. Am. J. Physiol. Gastrointest. Liver Physiol. 2011;300:G181–G189. doi: 10.1152/ajpgi.00419.2010.
  9. Oliveira, E. P. De, & Burini, R. C. (2014). Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress, 4191–4199. https://doi.org/10.3390/nu6104191
  10. Painelli, V. D. S., Nicastro, H., & Jr, A. H. L. (2010). Carbohydrate mouth rinse : does it improve endurance exercise performance ?, 2–5.
  11. Peters, H.P., van Schelven, F.W., Verstappen, P.A., de Boer, R.W., Bol, E., Erich, W.B., de Vries, W.R. (1993). Gastrointestinal problems as a function of carbohydrate supplements and mode of exercise. Medicine and Science in Sports and Exercise, 25, 1211–1224. doi:10.1249/00005768-199311000-00003
  12. Pfeiffer, B., Stellingwerff, T., Zaltas, E., & Jeukendrup, A. E. (2010). CHO oxidation from a CHO gel compared with a drink during exercise. Medicine and Science in Sports and Exercise, 42(11), 2038–2045. https://doi.org/10.1249/MSS.0b013e3181e0efe6
  13. Prado, E., Roberto, D. O., & Burini, C. (2014). Gastrointestinal Complaints During Exercise : Prevalence , Etiology , and Nutritional Recommendations, 44, 79–85. https://doi.org/10.1007/s40279-014-0153-2
  14. Stuempfle, K. J., Hoffman, M. D., & Hew-butler, T. (2013). Association of Gastrointestinal Distress in Ultramarathoners with Race Diet Association of Gastrointestinal Distress in Ultramarathoners with Race, 2, 103–109.
  15. Zügel, D. (2016). Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon.

Time Restricted Eating: What you need to know

In one of my previous article (Let’s talk Science: High Carbohydrate Vs High Fat), I  talked about starting your day with a high fat meal (eg avocado and eggs, fat smoothie etc) vs the traditional approach of refined high carbohydrate breakfast (Eg. toasted muesli, cereal and toast). But why stop there! The benefits achieved  by this can be taken one step further by not eating at all and extending your overnight fasted period.

 

“Break” + “Fast” = Breakfast

Whether you like it or not you fast every night, while you are asleep. Therefore, the term “breakfast” is defined by breaking the overnight fast. Breakfast is known as one of the most important meals of the day. I will not debate this because I believe this to be true as it will set you up for your day. However the time when we consume it does not necessarily need to be first thing in the morning.

Isn’t skipping breakfast bad for you? What are the benefits of fasting? Is there any science behind this? Is it dangerous? These are all the questions that people will often ask as soon as you hear the word ‘fasting’

 

Do I fast?

Yes, in fact most days I fast from 14-18 hrs (7pm-11am ish). It is one of the most liberating things I have ever done and has allowed me to free up my mornings. My mornings are now more productive than ever before, I have a clear mind and do not waste time,  instead I can jump straight into the task at hand.

Why would I suggest people try fasting?

If you are interested health, longevity and sporting performance fasting is something that you should consider.

Let’s take a look at the research

Although intermittent fasting is a relatively new area of science fasting is ingrained to our history and is a component of almost every religion. It is only recently that we have been able to gain a deeper understanding of the physiological mechanisms at play and therefore identifying the positive benefits associated with intermittent / prolonged fasting/ time restricted eating as a powerful longevity enhancing strategy.

 

Animals Studies (9-12 hr eating window)

The majority has been performed in animal studies which have shown increased muscle mass, fat loss, glucose tolerance, improved lipid profiles, decreased inflammation, increase mitochondrial volume, protection against mild age fatty liver, protection against obesity, gene expression, increase production in ketone bodies. This list alone should be enough to highlight the amazing potential of fasting. But while this does appear in animal studies, will we see the same benefits in humans?

 

Humans Studies:

This is a growing body of literature and is still in its infancy in terms of research. Intermittent fasting/ time restricted eating (11 hr eating window) has been shown to decrease breast cancer risk (36%). It has also been shown to increase fat loss in overweight and obese people and interestingly for each 3 hr increase in time of the  overnight fast duration there was a 20% fall in HbA1c (long term marker of blood glucose levels and an indicator of normal, pre-diabetic and diabetic status).

Human Eating in 12 hr window:

Even with a more lenient fasting/ eating window of time, research has shown a number of significant benefits such as: improved sleep, weight loss, and decrease in inflammation.

 

HFLC vs Fasting

In previous post we have discussed the positive attributes associated with a high fat diet such as increased insulin sensitivity and reduction in inflammation. All of these benefits are seen with fasting and in most cases are substantially greater along with a few other added benefits that you are unable to achieve from a HFLC diet alone.

Fasting compared with HFLC, especially prolonged fasting,  presents a dramatic increase in autophagy and apoptosis followed by a massive increase in stem cell production. Autophagy is a genetic program which clears always damaged protein/s and organelles within the cell (think of it as cell ‘house cleaning’) while apoptosis is a process where damaged cells self destruct and break down, a controlled process that is part of any organisms growth or development.. Essentially the two process work to prevent the accumulation of senescent cells (old cells) within the body. The body is dynamic and is constantly turning over cells, manufacturing new ones or clearing damaged organelles within cells and in doing so this helps to maintain the health and functioning of the body (for the science nerd, it maintain homeostasis). The prevention of senescent cells accumulation can assist in reducing tumor growth. Increase in autophagy and apoptosis have been linked to longevity, with research in mice demonstrating that when these two processes are increased the life span can increase by ~20%.

Fasting also appears to impact the stem cell number and production. It is stem cells regenerative nature that helps in mitigating the effects of aging.

One of the biggest difference in comparing fasting to a HFLC diet is mitophagy.  Mitophagy is a process which clears damaged mitochondria (the cell power houses, where we generate our bodies energy source) and recycles their defective components which is followed by generation of new mitochondria through process of mitochondrial biogenesis. Once again this minimises the effects of ageing. HFLC has been shown to modestly increase mitochondrial biogenesis but not as much as mitophagy. Therefore to gain full benefit of mitophagy you would want to look at including fasted windows.

NAD (Nicotinamide adenine dinucleotide) increases in a fasted state and decreases in a feed state. NAD is an essential component for a wide range of enzymes to function properly. Your mitochondria need NAD for energy production from glucose or fatty acids and any time there is damage occurring in the body it sucks up NAD causing the mitochondria to suffer. Therefore the act of fasting offers the ability to up-regulate NAD in the absence of fuel.

Additionally, fasting promotes repair of DNA along with improved blood sugar regulation, insulin sensitivity, blood lipid profile and inflammatory markers (CRP, TNF alpha)

 

Application

There are varying opinions on what consists as a fast. Some are of the opinion, like Rhonda Patrick who follows the strictests of definitions. She states that consuming anything other water constitutes as ‘breaking the fast’. Others, define a fast as the window void of any calories and that you can have black coffee etc to help extend the fast.

Which definition you select to comply with will greatly depend on your life circumstances and the goals and benefits you are wanting to achieve.

With results being shown in human with even a 12 h fast window, it all comes down to designing a method that suits your lifestyle. The classic and most renowned intermittent fasting/time restricted eating method is the 16/8 (16 hour fast & 8 hour eating window). Grant Schofield, Caryn Zinn, & Craig Rodger from New Zealand recently released their new book following on from “What the Fat” This time focusing on fasting with “What the Fast”. I was lucky enough to be at their book release, this is a great resource packed full of evidence based practice for anyone looking for some guidance and with an alternative approach to intermittent fasting. In their approach they provide a great lifestyle approach to fasting which allows you to maximise your benefits without impacting and restricting

you. Their approach involves a monday tuesday full day fast with a very low carb/ fasting mimicking meal on monday and tuesday night. The rest of the week they encourage you to eat LCHF and on the weekends relax and prepare for the monday/tuesday fast. Their book is full of great recipes and if you are interested in fasting this is a great resource to get started!

When it comes to fasting I believe you need to view it as another tool and I don’t believe that you should be too strict on applying it. I find when most people begin especially your A-Type personalities they go all in and start pushing the limits far beyond what is needed and end up in a catabolic state. Instead my advice would be to listen to your body and when it wants fuel have fuel and as you train your body over time to become fat adapted and break free from your eating habits you will begin to thrive off your fasted windows. It is important to understand your fasted windows should not be tough! You should not be hungry, if you are then EAT! I am also not saying you should restrict your food intake during your eating window, this is not a starvation diet. During your eating windows, nourish your body with good wholesome food and enough to meet your energy and or training demands.

 

My approach:

I personally follow the less strict definition as most people tend to do and will have black coffee in a fasted state and often will even break this rule and add some MCT oil (Not true fast) to extend my fast or help assist with a fat adapting training session (I will discuss the in great detail in future posts)

 

Eating Window Consideration:

Circadian Impact (metabolism changes throughout the day)

Just like our bodies responds to light, our metabolism functions on a 24 hr cycle and changes throughout the day. Timing of food consumption can have altered effects on your body. For example, it has been shown that there is a greater postprandial (following meal) glucose response at dinner compared to breakfast. This is due to humans being dayianal creatures (function during the day). Therefore eating late at night will have a greater impact on our health. For each 10% increase in calories consumed after 5 pm was linked to a 3% increase in the inflammatory biomarker CRP.

 

Summary:

Reduction in systemic inflammation is thought to be one of the greatest predictors of health and longevity. Reduced inflammation is linked to improvements in age, prevention of cancer and mental health issues. Therefore a strategy like fasting or time restricted eating or anything that greatly impacts systemic inflammation is a positive and should be considered.

View fasting as a tool to add to the toolbox that can enhance your health and longevity, don’t get caught up and or get too strict.  Listen to your body and remember shifting to utilise fat for fuel takes time so don’t rush the change.

 

References:

Baker, D. J., Childs, B. G., Durik, M., Wijers, M. E., Sieben, C. J., Zhong, J., … van Deursen, J. M. (2016). Naturally occurring p16Ink4a-positive cells shorten healthy lifespan. Nature, 530, 184. Retrieved from http://dx.doi.org/10.1038/nature16932

Chaix, A., Zarrinpar, A., Miu, P., & Panda, S. (2014). Time-restricted feeding is a preventative and therapeutic intervention against diverse nutritional challenges. Cell Metabolism, 20(6), 991–1005. https://doi.org/10.1016/j.cmet.2014.11.001

Choi, I. Y., Childress, P., Brandhorst, S., Navarre, G., & D. Longo, V. (2015). Periodic Fasting Mimicking Diet reverses age-dependent decline in neurogenesis and enhances cognitive performance.

Cohen, L. J. (2018). Fasting the microbiome to treat diabetes. Science Translational Medicine, 10(441). Retrieved from http://stm.sciencemag.org/content/10/441/eaat8529.abstract

Gabel, K., Hoddy, K. K., Haggerty, N., Song, J., Kroeger, C. M., Trepanowski, J. F., … Varady, K. A. (2018). Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study. Nutrition and Healthy Aging, 4(4), 345–353. https://doi.org/10.3233/NHA-170036

Gill, S., Le, H. D., Melkani, G. C., & Panda, S. (2015). Time-restricted feeding attenuates age-related cardiac decline in Drosophila. Science (New York, N.Y.), 347(6227), 1265–1269. https://doi.org/10.1126/science.1256682

Gillette, M. U., & Tischkau, S. A. (1999). Suprachiasmatic nucleus: the brain’s circadian clock. Recent Progress in Hormone Research. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/10548871

Hatori, M., & Panda, S. (2015). Response of peripheral rhythms to the timing of food intake. Methods in Enzymology, 552, 145–161. https://doi.org/10.1016/bs.mie.2014.10.027

Hatori, M., Vollmers, C., Zarrinpar, A., DiTacchio, L., Bushong, E. A., Gill, S., … Panda, S. (2012). Time-restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high-fat diet. Cell Metabolism, 15(6), 848–860. https://doi.org/10.1016/j.cmet.2012.04.019

Hine, C., & Mitchell, J. R. (2014). Saying no to drugs: Fasting protects hematopoietic stem cells from chemotherapy and aging. Cell Stem Cell, 14(6), 704–705. https://doi.org/10.1016/j.stem.2014.05.016

Hussain, S., Bloom, S., Gardiner, J., Hussain, S., Richardson, E., Ma, Y., … Gardiner, J. (2015). Glucokinase activity in the arcuate nucleus regulates glucose intake Find the latest version : Glucokinase activity in the arcuate nucleus regulates glucose intake, 125(1), 337–349. https://doi.org/10.1172/JCI77172.tive

Lee, C., & Longo, V. (2016). Dietary restriction with and without caloric restriction for healthy aging. F1000Research, (February). https://doi.org/10.12688/f1000research.7136.1

Longo, V. D., & Mattson, M. P. (2014). Fasting: Molecular mechanisms and clinical applications. Cell Metabolism, 19(2), 181–192. https://doi.org/10.1016/j.cmet.2013.12.008

Longo, V. D., & Panda, S. (2016). Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metabolism, 23(6), 1048–1059. https://doi.org/10.1016/j.cmet.2016.06.001

Longo, V. D., & Panda, S. (2016). Perspective Fasting , Circadian Rhythms , and Time-Restricted Feeding in Healthy Lifespan. Cell Metabolism, 23(6), 1048–1059. https://doi.org/10.1016/j.cmet.2016.06.001

Marinac, C. R., Sears, D. D., Natarajan, L., Gallo, L. C., Breen, C. I., & Patterson, R. E. (2015). Frequency and circadian timing of eating may influence biomarkers of inflammation and insulin resistance associated with breast cancer risk. PLoS ONE, 10(8), 1–11. https://doi.org/10.1371/journal.pone.0136240

Martinez-Lopez, N., Tarabra, E., Toledo, M., Garcia-Macia, M., Sahu, S., Coletto, L., … Singh, R. (2017). System-wide Benefits of Intermeal Fasting by Autophagy. Cell Metabolism, 26(6), 856–871.e5. https://doi.org/https://doi.org/10.1016/j.cmet.2017.09.020

Medsker, B., Forno, E., Simhan, H., Juan, C., & Sciences, R. (2016). Prolonged Nightly Fasting and Breast Cancer Risk: Findings from NHANES (2009-2010) Catherine, 70(12), 773–779. https://doi.org/10.1097/OGX.0000000000000256.Prenatal

Melkani, G. C., & Panda, S. (2017). Time-restricted feeding for prevention and treatment of cardiometabolic disorders. The Journal of Physiology, 595(12), 3691–3700. https://doi.org/10.1113/JP273094

Nas, A., Mirza, N., Hägele, F., Kahlhöfer, J., Keller, J., Rising, R., … Bosy-Westphal, A. (2017). Impact of breakfast skipping compared with dinner skipping on regulation of energy balance and metabolic risk. American Journal of Clinical Nutrition, 105(6), 1351–1361. https://doi.org/10.3945/ajcn.116.151332

Mattson, M., D. Longo, V., & Harvie, M. (2016). Impact of Intermittent Fasting on Health and Disease Processes. Ageing Research Reviews (Vol. 39). https://doi.org/10.1016/j.arr.2016.10.005

Study, M., Jimenez, J. J., Marcos-gragera, R., Perez-gomez, B., Llorca, J., Fern, G., … Fern, T. (2018). Effect of mistimed eating patterns on breast and prostate cancer risk (MCC-Spain Study ) 4,5,6 , 00(June), 1–10. https://doi.org/10.1002/ijc.31649

Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism, 27(6), 1212–1221.e3. https://doi.org/10.1016/j.cmet.2018.04.010

Youm, Y., Nguyen, K. Y., Grant, R. W., Goldberg, E. L., Bodogai, M., Kang, S., … Crawford, P. A. (2015). Ketone body β-hydroxybutyrate blocks the NLRP3 inflammasome-mediated inflammatory disease Yun-Hee, 21(3), 263–269. https://doi.org/10.1038/nm.3804.Ketone

Zarrinpar, A., Chaix, A., & Panda, S. (2016). Daily Eating Patterns and Their Impact on Health and Disease. Trends in Endocrinology and Metabolism: TEM, 27(2), 69–83. https://doi.org/10.1016/j.tem.2015.11.007

Zeevi, D., Korem, T., Zmora, N., Halpern, Z., Elinav, E., Segal, E., … Weinberger, A. (2015). Personalized Nutrition by Prediction of Glycemic Article Personalized Nutrition by Prediction of Glycemic Responses, 1079–1094. https://doi.org/10.1016/j.cell.2015.11.001

 

Cholesterol: Let’s Clear the Confusion

High cholesterol causes heart disease right?

Another case where an over simplification of science has come back and caused more harm than good.

What is cholesterol?

Cholesterol is a waxy yet essential blood lipid that has a vital role in the body’s metabolism and brain function,  it is required by almost every cell in the our bodies. It has a vital role in the body’s metabolism and brain function, therefore some cholesterol is required for optimal physical and mental functioning. It is also has a role in building hormones including oestrogen and testosterone, maintaining the integrity of cell membranes, and aiding in the absorption of vitamins.

Good vs Bad Cholesterol

We have all heard this:

  • HDL (High Density Lipoproteins) = is commonly referred to as the “good cholesterol”. HDL is considered to be beneficial as it transports cholesterol from the blood stream to the liver where it removed from the body.
  • LDL (Low Density Lipoproteins) = is commonly referred to as the ‘bad’ cholesterol. Excess LDL will increase the risk of clots due to the build-up of plaque on the inner walls of the arteries.

Recent research suggests that estimates of LDL particle number or concentration (LDL-P) is a better predictor of CV risk than LDL cholesterol (LDL-C). Basically this means that a larger number of smaller LDL particles will increase the risk of atherosclerosis (plaque in arteries narrowing and hardening them) when compared to fewer but larger LDL particles for a given total cholesterol concentration it is less the concentration of LDL in the blood but a better predictor is LDL particle size in the blood.

  • LDL-C which measures the concentration of cholesterol transported by LDL in the blood
  • LDL-P which measures the number of LDL particles in the blood

LDL-C tests have been the primary method of measuring LDL in the blood. It is cheaper Because the LDL-C measurement is a measure of the amount of cholesterol being carried in LDL, it is not a reliable measure of LDL particle concentration. For example: small, dense LDL particles have much less cholesterol than large, buoyant LDL particles. But it is these small, dense LDL that are more atherogenic. This has led to the concept that the overall number of LDL particles may be more predictive of cardiovascular risk.

Why is particle sizes and patterns Important?

LDL can be broken into two types:

Type A LDL= Large fluffy particles that “look like cotton balls and does do much damage”.

Type B LDL= Small, hard, dense particles which becomes oxidised and angry, sticking to the endothelium and creating inflammation.

So you really need to know your particle size and how many of Type A or Type B you have. Knowing your total LDL will not be as helpful, as knowing the particle size

 

The best predictor of Heart disease

There is no need for a in depth lipid panel you can get a great predictor of heart disease from a basic lipid panel. Total-to-HDL cholesterol is a ratio of total cholesterol triglycerides to HDL cholesterol. The cholesterol ratio is calculated by dividing your total cholesterol triglyceride number by your HDL number. The ratio is considered to be able to indicate the different levels of heart disease risk and has been shown to be the best predictor of cardiovascular disease risk.

Your total-to-HDL cholesterol ratio should be between 3 and 4 (according to New Zealand Health guidelines) to ensure healthy cholesterol levels and a substantially reduced risk of heart disease.

 

So how does this apply to HFLC?

The “bad science” that got us into this mess of believing that fat causes heart disease, have all been proven to be inaccurate and flawed. The main two are Ancel Keys Seven Countries Study (discussed in previous post: Food Pyramid: We Got It Wrong!), and the China Study. Low fat diets have been shown to be worse for our health in almost every way! Going low carbohydrate high fat leads to better health outcomes, disease prevention and longevity.

Consuming healthy fats raises your level of Type A fluffy particles, while eating more sugar raises the Type B angry little particles. Inflammation is what we should be concerned about as it is the leading cause  of heart/ chronic disease today. What Is causing the inflammation? You guessed it, high carbohydrate diet, high insulin level, processed foods, smoking and alcohol.

 

Improve your HDL Count

A split coconut, coconut cream and coconut oil in a bottleBoth Luric acid and (found in high quantities in coconut oil) and stearic acid (found in high quantities in animal fats) has shown to increase total-to-HDL cholesterol ratio more favorably than carbohydrates.

In other words, if you really want to impact your total HDL it is advantageous to restrict carbohydrates and get a majority of your calories from animal fats, coconut oil, and unsaturated fats like fish, nuts, avocado, and olive oil. One of the best ways to incorporate all of this into one diet plan is by following a high fat low carbohydrate or ketogenic diet.

 

Statins

Statins are a class of lipid-lowering medication, their ‘benefits’ have been grossly exaggerated while the side effects have been under-reported. There is even a class action taking place in America against statin drug companies for under-reporting side effects (muscle damage, memory loss, decreased immunity and diabetes). Statins have also been shown to decrease level of Co-enzyme Q10, a vital enzyme for energy transfer which is causing the muscle pain and damage and may be contributing to heart disease!

 

Other factors to consider:

  1. Chronic Inflammation and Stress

Both Inflammation and stress illicit similar physiological mechanisms/processes. Cholesterol levels are upregulated to bring the necessary nutrients to our tissue to assist them to heal and recover. If your stress/inflammation is not regulated and stays chronically elevated, your cholesterol level may persiantly stay high. This is typically due to a variety of lifestyle factor; diet, poor sleep etc

  2. Hypothyroid Related Issues

Thyroid hormones and cholesterol levels are intimately linked. In fact, thyroid hormone has a powerful influence on LDL receptor expression. The response is so substantial that it stimulates the LDL receptors in our liver and sex hormone-producing glands to soak up the LDL cholesterol in the blood like a sponge.

The reverse is true when our thyroid hormone levels are low. Our LDL receptors become less responsive. Resulting in excessive LDL cholesterol remaining in the blood for an extended period of time. The longer the LDL remains in the blood the more vulnerable it becomes to damage. This damage triggers plaque building process in blood vessels, increasing the probability of heart disease

 

Summary:

  • Cholesterol is required by almost every cell in the our bodies. It is essential that we are able to manufacture it
  • Over simplified method (HDL= good; LDL=Bad) creating confusion leading to poor recommendations in an attempt to minimise heart disease.  
  • Total-to-HDL ratio is more reliable predictor of heart disease than total cholesterol levels. Total-to-HDL cholesterol ratio should be between 3 and 4 to ensure healthy status.
  • High fat low carbohydrate or ketogenic diet, contrary to popular belief actually has a profound benefit on improving cholesterol levels
  • This is something that everyone should monitor at minimum once per year or if you are like me a passionate about performance get this checked along with other key biomarkers on a quarterly basis, to ensure you are functioning at a high level

 

References:

Adiels, M., Olofsson, S. O., Taskinen, M. R., & Borén, J. (2008). Overproduction of very low-density lipoproteins is the hallmark of the dyslipidemia in the metabolic syndrome. Arteriosclerosis, Thrombosis, and Vascular Biology, 28(7), 1225–1236. https://doi.org/10.1161/ATVBAHA.107.160192

Brinkworth, G. D., Noakes, M., Buckley, J. D., Keogh, J. B., & Clifton, P. M. (2009). Long-term effects of a very-low-carbohydrate weight loss diet compared with an isocaloric low-fat diet after 12 mo. The American Journal of Clinical Nutrition, 90(1), 23–32. https://doi.org/10.3945/ajcn.2008.27326

Bueno, N. B., De Melo, I. S. V., De Oliveira, S. L., & Da Rocha Ataide, T. (2013). Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: A meta-analysis of Randomised controlled trials. British Journal of Nutrition, 110(7), 1178–1187. https://doi.org/10.1017/S0007114513000548

Cromwell, W. C., Otvos, J. D., Keyes, M. J., Pencina, M. J., Sullivan, L., Vasan, R. S., … D’Agostino, R. B. (2007). LDL particle number and risk of future cardiovascular disease in the Framiningham Offspring Study – implications for LDL Management. Journal of Clinical Lipidology, 1(6), 583–592. https://doi.org/10.1016/j.jacl.2007.10.001.LDL

Dashti, H. M., Al-Zaid, N. S., Mathew, T. C., Al-Mousawi, M., Talib, H., Asfar, S. K., & Behbahani, A. I. (2006). Long term effects of ketogenic diet in obese subjects with high cholesterol level. Molecular and Cellular Biochemistry, 286(1–2), 1–9. https://doi.org/10.1007/s11010-005-9001-x

J., T., N.D., L.-M., C.H., T., M., N., J.D., B., G.A., W., … G.D., B. (2015). Comparison of low- and high-carbohydrate diets for type 2 diabetes management: A randomized trial. American Journal of Clinical Nutrition, 102(4), 780–790. https://doi.org/10.3945/ajcn.115.112581.1

Nguyen, P. (2014). Electronic records may threaten blinding in statin trials. British Medical Journal, 5239(November), 5239. https://doi.org/10.1136/bmj.g5239

Otvos, J. D., Mora, S., Shalaurova, I., Greenland, P., Mackey, R. H., & Goff, D. C. J. (2011). Clinical Implications of Discordance Between LDL Cholesterol and LDL Particle Number. J Clin Lipidol, 5(2), 105–113. https://doi.org/10.1016/j.jacl.2011.02.001

Westman, E. C., Yancy, W. S., Olsen, M. K., Dudley, T., & Guyton, J. R. (2006). Effect of a low-carbohydrate, ketogenic diet program compared to a low-fat diet on fasting lipoprotein subclasses. International Journal of Cardiology, 110(2), 212–216. https://doi.org/10.1016/j.ijcard.2005.08.034

Wood, R. J., Volek, J. S., Liu, Y., Shachter, N. S., Contois, J. H., & Fernandez, M. L. (2006). Carbohydrate restriction alters lipoprotein metabolism by modifying VLDL, LDL, and HDL subfraction distribution and size in overweight men. The Journal of Nutrition, 136(2), 384–389. https://doi.org/10.1093/jn/136.2.384

Let’s talk Science: High Carbohydrate Vs High Fat

This article is for those that enjoy diving into topics or for someone who likes to have evidence before they make a decision.

What is Science Telling Us?
As with anything in science there are a wide range of beliefs regarding best practice for nutrition. In my last post I presented an overview of the traditional nutritional beliefs and practices (Food Pyramid: We Got It Wrong!). The goal for this post is to update you on the current literature and to pull out relevant pieces of information that will help to educate and guide you towards making a informed decision.

Common Disadvantages Associated Carbohydrate:

What happens when we consume Carbohydrate (CHO)?

As blood sugar levels rise, the pancreas produces insulin, a hormone that prompts cells to absorb and store the glucose in your system. Insulin is a vital part of our bodies normal functioning and metabolism. But when constantly bombarded with glucose through a regular uptake of high CHO the body is forced to continuously produce insulin, resulting in chronically (long term) elevated levels of hormone.

Next, similar to when your body is exposed to a drug, your body becomes resistant to the normal levels of the hormone and will require increasing amounts of this hormone to carry out the same function. With your cells not effectively responding to insulin you end up with the accumulation of glucose in your blood. This response is known as insulin resistance and is the defining symptom of type II diabetes and can be linked to a whole host of other metabolic conditions.

So can Carbohydrates can be dangerous?

When we talk about CHO we need to acknowledge that there are good and bad CHO sources. Something the oversimplified food pyramid was aware of but neglected to include for simplicity. The bad CHO such as our highly refined & rapidly-absorbed (High Glycemic Index (GI)) CHO (e.g. cereals, white bread etc) are dangerous to your health. These high GI CHO foods cause your blood sugar levels to rise rapidly after eating them and force insulin to peak rapidly and remain within your body. If you eat enough of these types of foods, and regularly eat them as part of your daily diet, then you are almost guaranteed to end up with insulin resistance.

Another downside to this way of eating and elevated levels of insulin is that it creates a pro-inflammatory state that can damage tissues and blood vessels. People who have symptoms of insulin resistance also tend to have high levels of inflammatory markers within their body and blood. Inflammation is a process by which your body’s inflammatory markers and white blood cells work to protect you from foreign substances. High inflammation is seen in people who suffer from diseases such as Cancer, Alzheimers disease, Arthritis and Cardiovascular disease.

In short your diet could be forcing your body into an inflammatory state which is similar to some major diseases today. We could argue that this state of inflammation is the leading cause of chronic health diseases today.

Interesting fact: Cornflakes have a higher glycemic response than raw sugar!! Now that is crazy! Why? Due to being highly refined, they developed the the cereal to be quickly absorbed to fire up the pleasure signals in the brain to get you hooked and wanting more. Food is being manufacture to act like a drug!

Interesting fact #2: Diet/Sugar free soft drinks will produce an insulin response even though they are ‘sugar free’. They produce a response in your body similar to when you ingest CHO drinks. If you are struggling to lose weight or control your weight, try ditching the ‘diet’ soft drink and replacing it with soda water with lime/lemon for a week or two..

So What is Good Carbohydrate?

Quite simply put you are looking for unrefined whole foods that are found in nature (fruits, vegetables, starches etc) .                                                                               

Why? Our bodies have evolved to breakdown utilise these fuels efficiently plus they have not be denatured (loss of nutrients) due processing.

Rule of thumb stay clear or packaged foods and if you do choose a packaged item then select one with minimal ingredients. My rule is no more than 3 or 4 ingredients, and I must be able to pronounce and recognise all the ingredients on the list. Another trick is when in the supermarket, shop around the outside aisles and stay clear of the aisles.  

Take home message: Stay clear of proinflammatory CHO ie refined, high glycemic index. When selecting CHO into your diet choose unrefined whole foods that are found in nature.

Should I consume Carbohydrate?

Yes, although it should be minimised where possible, CHO is important and should not necessarily be completely neglected. What is important is the type of CHO you choose to include in your diet. One of the biggest mistakes I see with people trying to make a change to their diet and health is that they try to completely remove all CHO straight away. Removing a complete food group can be dangerous as you can eliminate a number of key micronutrients essential for health. These micronutrients may be more easily accessible in certain substrates eg CHO over fat. Always aim to have a varied diet to ensure you obtain a variety of micronutrients, as some are limited to certain foods.

Carbohydrate Tolerance (Insulin Sensitivity)

Carbohydrate tolerances or insulin sensitivity (ability to produce adequate insulin when required, to ensure efficient uptake of carbohydrate) will vary from person to person. Therefore, it is important to identify your tolerance. If you possess a high carbohydrate tolerance you should still be careful of what kind of carbohydrates you choose to eat, focusing on high quality sources, not using it as a hall pass to eat whatever you please.

 

Kick Start Your Day the Right Way!

Ditch the cereals that we have been brainwashed to think epitomises a healthy start to your day. These highly refined, insulin spiking foods will quickly derail your day before you even start. Regardless of your carbohydrate tolerance, we should all aim to begin our days with a healthy fat focused breakfast.

Why? Fat does not spike hormones (Insulin) it instead produces a steady release of energy that will keep you satisfied for much longer than CHO.

Two of My Favorite High Fat Breakfasts

 

  • At home: Avocado & Eggs on Spinach

 

A great nutrient dense breakfast and normally my first meal of the day.With loads of added healthy oils such as avocado and coconut oil. Feel free to add meat source like bacon (Yes bacon!) or salmon etc

  1. On the Go: High Fat Smoothie

Mixed Berries, Coconut Cream, Cocoa, Almonds, Spinach, Chia seeds (Add some MCT for bonus fat if you have any). There is endless mixes this is just a base I normally work off.

 

 

Key Takeaway Points:

  1. Carbohydrates are not evil, there are good and bad sources of it like anything.
  2. Not everybody responds the same to carbohydrate some can handle more than others.
  3. Excessive carbohydrate leads to insulin resistance and in turn inflammation which is leading cause of chronic disease today!
  4. Regardless of your carbohydrate tolerance, we should all aim to begin our days with a healthy fat focused breakfast