Snapshot of an athlete’s diet: from high to low(er) carbohydrate

A friend of mine sent a link to a debate between Alan Aragon and Jeff Volek on the use of a low carbohydrate (CHO) diet for athletic performance. For those who have a spare hour, I recommend watching it. If you have done a bit of reading around this, you will already know the general premise behind recommending a low CHO diet for athletes, but it is interesting nonetheless. When you watch it you’ll note both Aragon and Volek bring in population health data related to CHO intake. If there’s one way to increase confusion in the low CHO debate, it’s mixing general population and athlete-related information. Comparing the two does little else than muddy the waters. I don’t know that there was a ‘winner’ at the end of the debate, however the one thing both parties agreed upon was that athletes could meet their performance goals over a spectrum of CHO intake. This got me thinking about a friend of mine Dave who sought some advice over his diet and whether he would benefit from eating fewer carbohydrates.

Generally speaking, a ‘low CHO’ diet is a CHO intake of between 50g-150g per day. To give you an idea of what people generally eat, the median usual intake for CHO in New Zealand adults at the last Nutrition Survey in 2008/09 was 207g for females and 273g for males., with a general recommendation of anywhere between 45-65% total energy coming from CHO. Athletes are recommended to consume between 5-10g per kilogram body weight depending on their level of activity.  Dave weighs 68 kg and with the amount of activity he undertakes, (75 min – 150 min 5 days a week across two sessions a day, with a couple of longer sessions in the weekend), that would equate to 7-8g per kg bodyweight, or 476-544g  per day. The equivalent to 35-40 slices of bread. In the past I’ve only recommended the most active of clients (male) a CHO intake within that range – not only is it really difficult to eat that much CHO, but most athletes I know would also struggle to achieve a lean body composition.

Equally though, are those athletes who struggle to maintain their weight under a hefty training schedule, and Dave falls into that category. An avid multisporter who, like many of us ‘enduros’, competes in events fairly often throughout the year, Dave’s training intensity has increased, and the 68kg he’s weighing now is around 3kg lighter than three months ago, despite eating regularly to try and satisfy his ever-present hunger. This would be around race weight – which is great when you are 1-2 weeks out from your goal race – not good when you’ve got around 10 weeks until you toe the start line of the event that matters most. Athletes are in a better position to maintain strength, recover from sessions and be resilient against illness with a 1-2kg buffer of weight that naturally drops off as training gets more race specific. However, Dave has increased the number of group training sessions that (like many guys) end up giving both the body and the ego a workout – being harder and faster than normal. When I was chatting to Dave he said he was heading away for a couple of weeks for work and that he would use the time to train a bit less and ‘relax’ on the healthy eating front to regain some weight. Hmm…. A perfect formula for a bit of extra cushioning around the middle – not quite the weight gain he would like. This could prove more difficult to lose down the line and lead to under-eating in an effort to lean up.  Cue: illness, injury, grumpiness and poor recovery from training – not exactly an optimal training environment. I thought it would be interesting to show you what he was eating, and what I might suggest – (apologies for the ugly table):

Time Original diet Quantity MW suggestions Quantity
 5.15 am Bagel,white,toasted 1 bagel Berry Fruits 1 cup
Peanut butter 2 tsp Coconut cream, 0.5 cup
Banana,fresh 1 med Black Coffee 1 cup
Black Coffee 1 cup
 7 am Banana 1 med
 8.30 am Natural muesli 1.5 cups Avocado,raw 0.5
Banana,fresh 1 small Tomato,grilled 1 med
Trim Milk 200 ml Fresh fruit salad 1 cup
Poached eggs 3 large
10 am Latte, skim milk 300ml
 Blueberry muffin 1 large
11 am Apple 1 med Coffee 1 cup
with cream  2T
Raw almonds 0.3 cup
 1 pm Sushi 8 pieces Sushi  6 pieces
Sashimi 100g
 3 pm Choc wheaten biscuits 3 biscuits Greek  yoghurt 200g
Orange,flesh 1 med Seeds,pumpkin 2 T
Apple  1 med
Coconut  2T
7.30 pm Couscous, cooked 1 cup Pan-fried chicken breast 0.5 med
Chicken,breast,grilled 0.5 med Seeds,mixed 2 T
Stir-fried vegetables  2 cups Fresh salad 100g
Chopped raw vege 100g
Kumara,baked 150g
8.30 pm Chocolate 30g Dark chocolate 30g
 Tea with milk 1 cup  Tea with milk 1 cup

Outlined below is the different macronutrient profiles of each diet.

Nutrient Original diet MW suggestions
Energy (kJ) 11604.03 1190.37
Protein (g) 131.34 (19%) 142.73 (22%)
Total fat (g) 80.41  (30%) 172.46 (56%)
Saturated fat (g) 21.61 69.67
Polyunsaturated fat (g) 22.45 27.20
Monounsaturated fat (g) 30.21 54.32
Carbohydrate (g) 357.69 (51%) 159.43 (22%)
Sugars (g) 147.96 110.76

As you can see, the original diet is a quintessential athlete’s diet that Nancy Clark (and Runner’s World in the 90s) would be proud of. However, it wasn’t doing Dave any favours. While he enjoys vegetables and fruit, his meals are based around CHO choices. You’ll also note that it’s less than the recommended CHO guidelines for  ‘best practice’ sports nutrition. At 357g CHO, he’s consuming 120g less than the minimum recommended for his activity level.

Obviously, in order to maintain and potentially gain weight, it would be ideal to increase energy in the diet from good food sources. Going the traditional high CHO route I could tell Dave to include two 750 ml sports drinks during his sessions – that would equate to an additional 110g CHO per day. However that wouldn’t do much to satisfy his hunger and I’m not down with all of that simple sugar; endurance athletes place their body under so much oxidative stress due to the byproducts of training, the additional sugar load does not sit well with me. My advice is to up the dietary energy from fat, and include quality sources of protein – that way he will feel fuller, he won’t be burning muscle mass during his training, and he’ll gain a little bit of weight. The caloric intake isn’t too different between the two plans as for the next two weeks Dave’s training load is reduced. This makes it a perfect time to undergo a dietary change, making adapting to a higher fat diet easier in this instance. As I’ve discussed before, shifting from a high CHO diet to a higher fat diet requires metabolic adaptation that doesn’t happen overnight; the power output takes a hit, therefore it’s best not to do during a heavy training (and higher intensity) phase.

The CHO has decreased, but is at the higher end of the CHO intake of a ‘low CHO’ athlete – and is nowhere near the 50g or less required for nutritional ketosis. Most of the CHO is around his training times and, in addition, his protein sources are of higher quality with the addition of eggs and sashimi at lunchtime. These previously there was a high proportion of protein coming from cereal-based products. When Dave resumes a higher training load, increasing the amount of protein and/or fat at lunch and dinner would help support the increased load. These changes will help Dave become more ‘fat adapted’ while maintaining his weight. An athlete who would like to lose weight would have a lower CHO intake.

Most importantly, these choices were discussed with Dave and he felt confident that he could make these changes. This is one of a number of ways to change the macronutrient profile of the diet to support the training goals of an athlete and this is just one example, designed to give you an idea of how a lower CHO diet can be achieved.

(PS Grain-free, dairy-free, flour-free pumpkin loaf in the recipe section)

2 thoughts on “Snapshot of an athlete’s diet: from high to low(er) carbohydrate

  1. Hi Mikki, I have couple of questions from your blog based on what I have learnt in my lectures this year.

    Interesting observation you make that most athletes you know wouldn’t be able to maintain body composition with an intake of 7-8g/kg/BW. Not sure if you followed the NY marathon in the weekend where the two winners were Kenyans, who are well known to eat excess carbohydrate than this and appear to maintain their body composition well. Do you think they would benefit from following this approach?
    Also why would you use these general AIS recommendations and not the latest from IOC expert panel? Which focus on promoting carbohydrate availability to match training volumes across different days? If he is training 75-150mins each day, why not adjust calorie and carbohydrate accordingly to support such a training plan?
    Also you say the traditional approach would be to provide 2 bottles of sports drinks per session to Dave, yet the recommendations you reference don’t support this. If he is training 75-150mins across 2 x sessions per day then this would perhaps equate to 37-75min sessions, therefore these recommendations would support only small amounts of carbohydrate or a mouth rinse only. If he were to train for a 150min session, perhaps using 2 bottles of sports drink for this session would help maintain optimal glucose metabolism for competition and help train the gut for race to avoid gastro-intestinal problems? That is of course if you are recommending carbohydrate during his multisport competition, water maybe fine if Dave is happy to not perform optimally during competition but based on this blog I’m not convinced that would be Dave’s style.

    • Hi thanks for taking the time to comment on this. 🙂 This post was not about race nutrition. However, the demands of a marathon are quite different to that of a multipsort event, where the top-end elite athletes perform at up to 90% of their VO2 max for a relatively short period of time. In comparison, the physiological demands of a multisport event are often dictated as much by terrain as by fitness, and are a lot lower. This then means that they glycolytic demands are less and they would utilise more fat as fuel because of this – as you would hope. That said, this post was more about changing the daily diet to promote fat adaption, rather than the actual event nutrition. However, with regards to your point about practicing racing nutrition – absolutely you want to ensure you can take on board nutrition throughout the race, and I’ve mentioned in a previous post, practicing this every two-three weeks during a key session is one way to do it in order to have confidence that you can take on board fuel at an increased rate, without the overload of simple CHO week in, week out. I can’t tell you that the elite Kenyan marathoners running (and winning) NYC marathon would benefit from this type of diet. Typically those top-end athletes are better able to tap into their fuel stores compared to age-grouper athletes, and there are many other physiological factors which would determine athletic success beyond that of diet (running history, bone and body composition etc). Being a professional runner, life is quite different compared to that of an age-grouper, and the amount of stress placed on the body through training will be mitigated more through being able to have in place recovery techniques that are not afforded to that of an age-grouper athlete, who (mostly, and in this case) juggles the demands of work, life, family and training. The body reacts to stress in the same way regardless of where it comes from, and any way to minimise this stress through a reduction in sugar in diet is a bonus in my book. The increased sources of essential fats in the diet that help with cell membrane structure, and the increased quality of the protein that has come from reducing CHO only helps with reduction in inflammation created by this stress. It would be an interesting study to put elite Kenyan athletes on a higher fat diet to see how their training and performance fares – as to become fat adapted you can increase the intensity during training to which fat is burned as a fuel – of course (as I’ve mentioned previously when talking about marathon training and food) you’d also want to support the glycogen demanding aspects of their training (high intense work) with CHO fuelling, as that’s when you need it. We also need to consider where in the diet the CHO come from. Looking specifically at Kenyan athletes, who have a high CHO, low protein and low fat diet, their CHO sources are predominantly unrefined which would be quite different from the athlete in NZ/US who has a similar diet composition. As studies have pointed out, this is likely due to the availability of foods here compared to, say, Kenya. http://www.ku.ac.ke/schools/graduate/images/stories/docs/publications/2008/Food-and-Macronutrient-Intake.pdf

      The guidelines I’ve outlined as ‘best practice’ are in line with the IOC/American College of Sports Medicine and AIS recommendations – the individualisation of these is taken into consideration as they are adjusted according to body weight, and there is a range given – as generally speaking CHO intake is lower on days where there is reduced training, (http://www.ajol.info/index.php/sajcn/article/view/88379, and if following these types of guidelines the additional CHO from the upper end of the range would drop out when you don’t need to account for recovery fuel etc.

      With regards to the sports drink – sorry if I didn’t outline what I meant properly – it was 2 x sports drinks across the training (for two sessions; = 110g additional CHO for your standard 750ml prepared sports drink) – not 2 per session! This would be one way to up the CHO in the diet when weight maintenance/gain is a goal – as the exogenous fuel would be used (for example to have throughout session, then finish off what has not been consumed during the session.) However, as the goal is to reduce reliance on CHO during training and become better ‘fat adapted’ (one reason Dave was interested in speaking to me about his diet) this would clearly not be in line with that goal, as the body will use glucose, switch off glucagon (fat burning hormone) and this would not ‘teach’ the body to use fat as fuel. Once fat adapted, the body can actually burn fat at higher intensities in the presence of glucose – however this is not the case for an athlete who is dependent more on CHO. Glucose rinse might be a great idea for athletes who aren’t concerned with becoming fat adapted, as the idea behind the rinse is to Further, the increased load of sugar would leave Dave hungrier throughout day, as often is the case when you put simple sugars in the body that are cleared quickly from the bloodstream, wrecking havoc with energy levels also. Not ideal. Endurance sessions tend to be a longer and a shorter session, not typically split equally.
      The goal (in my opinion) is not about being able to go and race without CHO – it’s not desirable (nor possible). But the goal is to become more metabolically flexible so you’re not 100% relying on CHO as a fuel source when you race. You can achieve this by upping fat in daily diet and reducing CHO – which, if done well, can also promote recovery and be more nutrient dense (as is the case here). For multisport events, luckily, this means we are better able to tolerate fat and protein along with CHO, and not just water. Race nutrition/training and daily nutrition are quite different. 🙂

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