Low-carb, high-fat – aka keto or fat adapting. You’ve mostly likely heard about it, trialled it yourself, or know some who has. It’s practically the new “cooler” version of the Atkins diet which has caught the eye of many endurance athletes.
When I first heard about this diet, I immediately thought, “Nope, not for me. I’m not giving up my pasta, bananas and sweet potato chips!” There’s no doubting I perform better with carbohydrates. But nutrition is a unique concept, and for some this style of eating is beneficial for reaching their goals. Typically, a low carb, high fat diet is consumed to aid in weight loss or manage particular medical conditions.
Carbohydrates (found in foods liked whole grains, pastas, fruits, veggies, and legumes) are our main source of energy for our brain and working muscles. When we exercise, our body breaks down carbohydrates into glucose for energy, and stores it in our muscles (known as glycogen stores). When we don’t have enough glycogen to fuel us, our body looks to other sources, like muscle proteins (which we do not want to use!!) and fats. However, using fat for energy can be harder to initiate for many, particularly if you do not have much body fat to begin with!
If you decide to follow this style of eating, it is important you understand what your body needs and how much. I have had many low-carb athletes come to me who have not been eating a wide enough variety of foods to meet all their nutrient requirements (such as fibre and B vitamins), and as a result have struggled with their performance. Low carb, high fat diets are much more than just cutting your carbs and increasing your protein intake.
If you have recently transitioned to this style of eating, or want to explore it, I’d recommend speaking to an Accredited Practising Dietitian or Sports Dietitian who understands triathlon.
Accredited Practising Dietitian & AG AUS Triathlete