Macronutrients: Carbohydrates

Carbohydrates are the body’s main energy source. All carbohydrates come from plants but not all are created equal. There are two categories: Simple carbohydrates and complex carbohydrates. Understanding the difference between these two is essential for optimal health, performance, and energy levels.

Simple carbohydrates are mostly sugars (such as white sugar, honey, syrup, candy, etc.) and highly refined carbohydrates from grains (such as white flour, white rice, white bread, sugary cereals, etc.). Simple carbohydrates are digested very quickly, leading to an energy boost within minutes, usually followed by a crash.

In contrast, complex carbohydrates have some protein and fibre. They take longer to digest, which means their energy is released slowly over several hours. They also contain many essential vitamins and minerals. As such, foods like beans, lentils, oats, wholemeal bread, brown rice, wholewheat pasta, and other whole grains (like quinoa) should form a large part of most people’s diets.

There are few guidelines for the minimum required carbohydrate for a sedentary person. However, most athletes need at least 3 to 5g of carbohydrates per kilogram of bodyweight per day1. Endurance or team sport athletes averaging an hour of exercise a day need 5 to 7g/Kg/day, and up to 12g/Kg/day if they are in heavy training (for example, cycling 6 hours a day)2.

Regardless of sport, these requirements depend on the training the athlete has that day. You may only need 3g/Kg/day of carbohydrates on a rest day, but 7g/Kg/day on a day when you do a two hour long run.

As with most things, the key is to get the right types of carbohydrates, at the right time, in the right amounts.  Next week we’ll look at how to use the different types of carbohydrates to improve performance.


1. Thomas, D.T., Erdman, K. and Burke, L. 2016. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. 2017 Jan;117(1):146. doi: 10.1016/j.jand.2016.11.008.

2. Vitale, K. and Getzin, A. 2019. Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients. 2019 Jun; 11(6): 1289. doi: 10.3390/nu11061289

Leave a Reply

Your email address will not be published. Required fields are marked *