The importance of dietary fiber

Fiber comes from plants and is forms of carbohydrates. But unlike other carbs, fiber can’t be absorbed and broken down by your digestive system. As a result, it does not provide energy. Brought by the diet, fiber contributes to the regulation of the transit and has other positive impacts on health.

There are two types of fiber:

1. Soluble fiber

In contact with liquids, soluble fiber forms a gel in the intestine. The intestine thickens and therefore soluble fiber slows down the absorption of nutrients (cholesterol, fat, …) as well as digestion (especially carbohydrates).
The best known are called pectins, gums and mucilages.

2. Insoluble fiber

Insoluble fiber doesn’t dissolve and swell by absorbing water. This increases stool volume and stimulates intestinal contractions. As a result, transit is accelerated and stool frequency is also increased. Insoluble fiber helps fight against constipation.
The best known are lignin, cellulose and hemicellulose.


– Digestive health
– Prevention of cardiovascular diseases
– Prevention of the onset of type 2 diabetes
– Prevention of colon cancer.
– Reduced digestion rate, effect of satiety
– Fiber serves as food for colonic bacteria (the microbiota), a central defense and control organ of the organism.


For a healthy adult, recommended nutritional intakes are 25 to 30g per day including half of soluble fiber and the other half of insoluble fiber.


– Complete cereals (insoluble fiber)
– Dried vegetables (red beans, white, chickpeas …). ¾ are in the form of insoluble fiber and ¼ in soluble fiber.
– Raw fruits and vegetables. We find ⅔ insoluble fiber and ⅓ soluble fiber.
– Oilseeds (almonds, peanuts …) and dried fruits (prune, dried apricots, raisins …).

The best is to vary the sources of fiber in order to have as many intakes of soluble and insoluble fibers.


– Gradually introduce wholegrain (wholemeal bread, whole rice …) instead of refined cereal products which contains less fiber (bread, rice, pasta…)
– Eat legumes once a week (beans, lentils …)
– Add fruits and vegetables to dishes

Important : Too much fiber can cause flatulence, bloating, diarrhea or irritation for the most sensitive people. In this case, prefer cooked fruits and vegetables because cooking makes them less irritating.

Article written by Amélie Vincent, dietitian

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