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|
|Raw almonds||0.3 cup|
|1 pm||Sushi||8 pieces||Sushi||6 pieces|
|3 pm||Choc wheaten biscuits||3 biscuits||Greek yoghurt||200g|
|Orange,flesh||1 med||Seeds,pumpkin||2 T|
|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|
|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|
|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%)|
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)