Chris Froome sent a picture of his breakfast on rest day of last year’s Tour de France: smoked salmon, avocado and poached eggs. A breakfast with a high content of fat and low in carbs. I learned about this low carb high fat (LCHF) diet last april and decided it was interesting enough to give it a try. Even though the concept of LCHF goes against my current medical knowledge. To my understanding the body simply needs carbs during high intensity exercise, but what about the times when we don’t exercise?
Below you will read my experiences so far. In 2014 I tried the Paleo diet for athletes. Like LCHF this diet encourages to eat a more whole foods diet, eating seasonally grown produce, avoiding refined sugars and processed foods. These diets have a different advice on dairy products. Paleo says no to dairy which was a challenge for me as an athlete. I use cottage cheese, quark and milk on daily basis to provide my body with the necessary proteins. After half a year experimenting I left the paleo diet. The only thing I still do is to have salads for lunch. For the new ‘experiment’, the LCHF diet, I needed to change the carbs versus fat ratio in my dietary intake.
The idea of LCHF diet is to train the body to use fat as the preferred energy supply. Blood sugar and glucogen become secondary fuels. By doing this the promise is that you can train harder, perform longer and recover faster. Scientists behind this concept claim that the human body can be trained to use fat as a primary energy supply independent of exercise intensity. Since the human body has a sufficient fat storage for hours of exercise, versus a glycogen storage for ‘only’ 60-90 minutes of exercise, this would be ideal. To able to influence your freshness during the final part of a race or a game with your diet.
The first weeks of LCHF were challenging. The dietary intake needs to contain mainly fat (70%), moderate proteins (15-20%) and a carb intake of 20-50g a day. This means completely avoiding sweet sugary foods and starchy foods like bread and pasta. And a low intake on fruits: one banana already contains 20g of carbs. As I started my experiment during the road race season I decided to give my body more time to get used to LCHF. Only on rest days and days with low intensity training I was strict. On race days I sticked to my usual race-day-meal-plan.
The good after 6 months: less bloating after dinner, a reduction of my waist circumference of 10cm and being able to be satisfied with 3-4 meals a day. It became easy to work a whole morning at the sports clinic without an urgent need to snack around 10 o’clock. My performances in road racing did not improve, but this cannot be blamed to a change of diet only. The bad was that I noticed that sometimes during high intensity exercise I ran low on glucose and needed an extra energy bar to avoid hitting the wall. I learned that this could be avoided by having a pasta meal for breakfast on a day with high intensity exercise.
Discussing LCHF with experts like Fred Brouns, Emiritus Prof. Chair Health Food Innovation at Maastricht University, confirmed my experiences written above. There is currently no evidence in favour of a strict LCHF diet for athletes. During high intensity exercise carbohydrates are the dominant fuel, fat is used at the same time to a lesser extent. Like most processes in the human body, energy requirement is not a black and white thing, but rather a matter of adapting resources to requirements.
It is generally recommended to eat a more whole foods diet, containing seasonally grown produce and avoiding refined sugars / processed foods. For athletes it is important to adjust the nutrition plan accordingly to the training plan. To personalise the nutrition to daily needs to reach your goals.
Asker Jeukendrup – Ketogenic diets for athletes, Dec 1st, 2016