Are low carb, high fat (LCHF) diets suitable for athletes?

By guest blogger, Coach and Advanced Sports Dietitian, Alison Patterson

LCHF diets are a hot topic in the sports nutrition world at the moment. Pick up a popular magazine, watch the TV or scan the internet and you’re likely to find devotees preaching the benefits of LCHF diets. But what if you’re a serious exerciser? Let’s take a closer look at LCHF diets and their suitability for athletes.

WHAT IS A LCHF DIET?

As the name suggests LCHF diets are low in carbohydrate and high in fat. However, there is not one single LCHF diet. In fact, there are a number of variations of LCHF diets particularly with regards to the amount of carbohydrate and fat.

In a Ketogenic LCHF approach, carbohydrate intake is restricted to less than 20g per day. To put that in perspective, that is roughly equivalent to the amount carbohydrate found in of one slice of bread. Because of the minimal amount of carbohydrate permitted on a strict Ketogenic LCHF approach this style of eating requires a huge amount of planning and diligence (and can challenging to eat socially). Other variations of a LCHF diet allow more carbohydrate, most in the range of 100-150g per day, which can be easier to follow – but still require substantial planning.

With regards to amount of fat, again there is a wide variation in recommendations, however fat typically ends up accounting for at least 50% of daily energy intake. Importantly, a number of LCHF advocates promote that this fat should be “healthy” fats – plant based fats such as avocado, olive oil and nuts.

WHAT ARE THE BENEFITS OF A LCHF DIET FOR ATHLETES?

There are several potential benefits to following a LCHF style of eating – these include:

  • Promotion of food choices based on whole foods rather than supplements
  • Many of us do eat too many carbs for the amount of activity we do – it’s not always a bad thing to be more mindful of overall carb intake
  • Meal timing is not strictly dictated, instead LCHF eaters are encouraged to use their appetite to guide timing of meals (although this can also be a downside, particularly for athletes with a low appetite after training)

WHAT ARE THE NEGATIVES OF A LCHF DIET FOR ATHLETES?

Before you jump on the LCHF bandwagon, it’s important to understand that there are a number of potential downsides to following a LCHF style of eating, particularly for athletes. These include:

  • Loss of top end gear – particularly the ability to pick up the pace or train/compete at high intensity
  • Training can feel harder compared to when training with carbs
  • Initial adaptation period can have a number of unpleasant side effects including fatigue, mood disturbances, irritability & headaches
  • Can be an expensive way of eating
  • Can be low fibre if not well planned which can lead to digestive issues
  • Easy to blow daily energy needs if selecting low nutrient, poor quality high fat foods

IS THERE ANYTHING WE STILL DON’T KNOW ABOUT LCHF DIETS FOR ATHLETES?

There is still a lot we don’t know about LCHF diets and athletes. In particular there are still a number of areas that we don’t yet understand including the long-term effects of LCHF diets on:

  • Gut microbiome
  • Hormones (particularly in females)
  • Micronutrient balance & potential deficiencies
  • Overall health and chronic diseases

BOTTOM LINE…

If you are a serious athlete wanting to push the pace and train and compete at a high intensity, then a LCHF style of eating is likely to compromise your performance and limit your ability to use your top gear. However, you may benefit from strategic periods of lower carb training to get the best of both worlds.

If you are someone who is active, but doesn’t train or compete at a high intensity then there may be some benefits to trialling a LCHF style of eating – BUT this needs to be done strategically (don’t wing it!) and with the knowledge that there a still a lot of questions about the long term effects of this style of eating.

**Please note; this is general advice only. If you have any medical conditions this needs to be discussed in more detail to determine the most appropriate nutrition plan for you.

If you would like to find out more, get an individual plan or ask Ali a question head to www.alisonpatterson.com/

 

 

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