Dietary fiber

Basic nutrition: dietary fiber
The basic nutrition is located at the bottom of the sports nutrition pyramid. These are regular products that you can buy in any supermarket: vegetables, fruit, dairy, nuts, fish, eggs, whole wheat bread, etc. These form the basis of healthy sports nutrition. This blog focuses on products that contain dietary fiber. What is dietary fiber, where can it be found and why are they important for you as an athlete?

What is dietary fiber?
Dietary fiber is (largely) indigestible particles in food. Carbohydrates, proteins and fats are broken down in the gastrointestinal tract, after which they can be absorbed into the blood and ultimately play a role in the cells as a building block or fuel. This does not happen with dietary fiber. The structure of dietary fiber is similar to that of carbohydrates (long chains of glucose molecules), but the way in which they are attached to each other is different from carbohydrates. The human body does not have enzymes in the small intestine that can break this bond. As a result, they pass through the small intestine undigested and end up in the large intestine. The so-called fermentable dietary fibres are partly broken down by bacteria there, which means that they still provide a small amount of energy: 2 kcal per gram. Non-fermentable dietary fibres pass through the large intestine unchanged.

Where can dietary fibre be found?
Dietary fibres can be found in plant products, such as vegetables, fruit, nuts, legumes, seaweed, potatoes and grains. Most of these products contain a mix of both fermentable and non-fermentable dietary fibres. A balanced diet with many different plant products is important to get enough dietary fibre. Refined grain products (such as white bread and white rice) do not contain dietary fibre, unlike whole grain varieties. Fruit juice also contains less dietary fibre compared to fruit in its original form.

What is the function of dietary fibre?
Dietary fibres help to keep the environment in the intestine healthy and prevent problems such as constipation. Fermentable dietary fibres stimulate intestinal function and keep the stool in the intestine soft. Non-fermentable fibres increase the volume of the intestinal contents. Together they ensure a smooth intestinal passage of the stool. In addition, a fibre-rich diet is associated with a lower risk of cardiovascular diseases, a lower risk of diabetes and a lower risk of various forms of cancer, such as colon cancer. Dietary fibres ensure a feeling of satiety, which means that a diet with many fibre-rich products also makes it easier to achieve or maintain a healthy weight. For athletes, it may be useful in specific circumstances not to eat too large amounts of fibre, for example if you are sensitive to intestinal complaints, such as cramps during exercise. In the event of recurring gastrointestinal complaints during exercise, it is wise to contact a sports dietician and not simply switch to a low-fibre diet, as this has consequences for the intake of dietary fibre but also of vitamins and minerals.