Crossfit and the paleo diet

Whether it is to lose weight, improve sports performance or live in better health, more and more people are adopting the Paleolithic diet. This diet has many similarities to other high protein and low carbohydrate diets, such as Ideal Protein, Atkins, Montignac and Dukan. However, the Paleo Diet goes beyond food and is also about lifestyle, including physical activity and sleep. It is especially popular with athletes in power sports like CrossFit and weightlifting.

Paleo… what?

The great premise of this way of eating is that the human genome (our genetics) would not have evolved at the same rate as our environment, which has radically changed. Still according to its followers, as our genes determine our nutritional needs, the paleo diet would be the best suited to meet them. Also, the current Western diet is thought to be the cause of chronic diseases such as diabetes, cardiovascular disease and cancer [1].

To meet the criteria for the paleo diet, grain products, milk and dairy products, refined sugars and alcohol must be eliminated from the diet. The Paleolithic plate therefore contains meats, poultry, nuts and seeds, as well as vegetables and fruits such as avocados and coconut [2].


  • Given the restaurant’s limited number of fast foods and foods that meet the criteria of the Paleo diet, its followers need to cook more, with fresh ingredients.
  • This diet is therefore less rich in salt, added sugars and processed products.
  • The paleo diet provides an effect of satiety, given the large amount of protein and fat on the menu.
  • It contains a good proportion of fruits and vegetables and good fats (fish, avocado, oils, nuts and seeds).


  • This diet eliminates two food groups: grain products and dairy products, which increases the risk of deficiency of essential nutrients such as group B vitamins, vitamin D and calcium [3].
  • Eliminating grain products (22% to 40% of daily intake) can make the diet low in carbohydrates, leading to a risk of general weakness, headaches and lack of energy, especially during physical effort.
  • The amount of saturated fat (28% to 47% of daily intake), mainly from meats, may contribute to a long-term increase in the incidence of cardiovascular disease. In the short term, large amounts of fat can be difficult for some to digest and cause gastrointestinal discomfort.
  • It’s not ideal before a workout.
  • The paleo diet can quickly become monotonous and limiting when it comes to dining out or in society.

Eat paleo to perform?

As carbohydrates are the preferred source of energy for the brain and muscles, it is seldom advisable to reduce the proportion to less than 45% of total intake [4]. Yet, this is what the Paleo Diet suggests. Carbohydrate intake must be present at least during the moments surrounding training (before and after) in order to provide the body with the energy it needs to perform and recover well. The paleo diet is very popular with CrossFit enthusiasts, but it is not optimal for competitions which tend to consist of, in general, 5 short and intense events spaced about two hours apart.

Although fruits are a source of carbohydrates and provide short-term energy, their effect is limited over time. In return, grain products can provide longer term energy; this is why they are called “slow sugars”. As for recovery, it is optimized by a combination of carbohydrates and proteins [5].

The paleo diet is based on the evolution and change of the food environment, and it is true that industrial transformation is not beneficial to our health. But change and evolution are not all bad. Advances in scientific knowledge can help us better understand how our bodies work and what it needs to perform better.


Finally, be aware that studies favorable to the adoption of this diet are often done in the very short term in addition to involving only a few subjects and often no control group. You could try heading for a less restrictive version of the Paleo diet instead. The Mediterranean diet, for example, includes good types of fat, meat alternatives, whole grains, milk and alternatives, and lots of fruits and vegetables and has been shown to have tremendous benefits for general health [6].


[1] Rapport d’une Consultation OMS/FAO d’experts intitulé Régime alimentaire, nutrition et prévention des maladies chroniques:

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[2] //

[3] Österdahl, M., Kocturk, T., Koochek, A., & Wändell, P. E. (2008). Effects of a short-term intervention with a paleolithic diet in healthy volunteers.European journal of clinical nutrition, 62(5), 682-685.

[4] Clinical Sports Nutrition, 4th Edition, 2009, by Louise Burke (Author), Vicki Deakin (Author)

[5] //

[6] //

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