Dietary fibre

Description

Dietary fibres are carbohydrates that are incompletely absorbed in humans and some animals. Like all carbohydrates, when they are metabolized they can produce 4 kcal of energy per gram. However, in most circumstances, it is less because of the limited absorption and digestion capacity of the human digestive system.

Dietary fibre consists mainly of cellulose that is indigestible because humans do not have the necessary enzymes to degrade it, unlike ruminants.

There are two sub-categories: soluble and insoluble fibre. Whole grains, fruits (especially plums, prunes, figs ...) and vegetables are good sources of dietary fibre.

There are many health benefits of a fibre rich diet. Dietary fibre can reduce the risk of gastrointestinal problems such as constipation and diarrhea by increasing the weight and size of stools and softening them.

Insoluble fibre, found in whole grain flour, nuts and vegetables, in particular stimulate peristalsis - rhythmic contractions of intestinal muscles that move the bolus along the digestive tract.

Soluble fibre, found in oats, peas, beans, and many fruits, breaks down in water in the intestinal tract to produce a gel which slows the passage of food through the intestines. This can help reduce the levels of glucose in the blood because it can slow the absorption of sugar.

The refining of grains has the effect of depriving them of their bran containing cellulosic components but also proteins, minerals and vitamins.

Satiety and body weight

To get a feeling of fullness with a low fibre diet, it is necessary to ingest large amounts of foods with high energy density (fats, carbohydrates, proteins), which promotes weight gain. Thus, several studies have shown that after ingestion of food rich in fibre, satiety is higher than that of a comparable low fibre meal. More interestingly, the ingestion of a meal rich in fibre leads to a reduction of energy intake during the day following the meal, compared to a low fibre meal. Some studies have shown that low-calorie diets rich in fibre helps weight reduction.

High fibre diets high are recommended

It must be remembered that the food which has influenced the selection of our genetic heritage hundreds of thousands of years ago was naturally very rich in fibre, such as that is still consumed in populations with very traditional dietary habits.

A high fibre diet should be considered, a priori, as good for and well adapted to our physiology.

The practical recommendation is to vary fibre sources using fibre-rich foods such as fruits, vegetables, legumes and grains.

Fibre sources

See the list of foods that provide the most fibre

Needs

Epidemiological studies show a reduction in relative risk when consuption exceeds 25 grams of fibre per day. The recommendation is to reach at least this amount and if possible 30 g of fibre per day for adults. Effective amounts of soluble fibre are 10 to 15 g per day.

RNI value is 100% of 30g for adults in Nutrimeter ®.

(Source: "Recommended dietary allowances for the French population," the CNERNA-CNRS. Edition coordinated by Ambroise Martin.)

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