Dietary fiber is an important element in all reduction diets and most health-related diets. Why is it so important, how does it affect the human body and from what sources it can be obtained? Find out what fiber is in the diet!
Dietary fiber – what exactly is it?
Dietary fiber (food fiber) is a building block of plant cell walls that is resistant to the digestive enzymes of the human digestive system and passes through the intestines as an undigested residue of food intake. According to this definition, we include fiber
- carbohydrates (polysaccharides) not assimilable – (cellulose, hemicelluloses, pectins),
- non-absorbable lipids (vegetable waxes),
- lignin which is a derivative of alcohol,
- other compounds such as saponins, phytates, suberin (covering the underground parts of plants) and cutin (located on the surface of the fruit).
The dietary fiber is divided into soluble – pectin, gums and mucous membranes, and insoluble – cellulose, hemicelluloses and lignin.
For the ingredient to be classified as dietary fiber, it must meet one of these four characteristics
1) reduce the time of intestinal transit and increase the volume of stool
2) stimulate fermentation processes in the large intestine
3) reduce total and LDL cholesterol levels in the blood
Quite an interesting case is resistant starch (RS – resistant starch), which does not occur naturally in nature, and is formed only when heating starch products. As a result of a long exposure to high temperatures, part of the starch molecules are destroyed and lose the ability to gel. It is these processes that make it resistant to digestive enzymes.
Dietary fiber – meaning
Food fiber has many important functions in the human body. His most famous property is the binding of water.
- It causes the increase of fecal mass and the improvement of intestinal peristalsis, it improves and regulates the rhythm of bowel movements.
- It causes faster bowel filling and directly affects the increased feeling of satiety, and therefore facilitates the slimming process.
The reduction process may also help reduce the absorption of carbohydrates taken with food and the ability to lower blood sugar after a meal. In addition, dietary fiber has the ability to bind heavy metals, toxic substances, cholesterol and bile salts, acting detoxifyingly and therapeutically on the body. Adequate fiber supply is of prophylactic importance in the prevention of intestinal cancer, haemorrhoids, leg varicose veins, atonic constipation, as well as inflammatory and diverticulitis.
Products rich in fiber
The main source of fiber in the diet is natural fiber, which is contained in plant products, and therefore in cereals, vegetables and fruits. The insoluble fiber fractions can be found in wholewheat bread and whole-grain rye bread, broccoli, beetroots, Brussels sprouts, peas, Italian cabbage, green beans and in the largest quantities – in wheat bran. They improve intestinal peristalsis by binding water and increasing stool volume. The soluble fiber fraction occurs in immature fruits as well as carrots and beets. Consuming these products reduces the level of cholesterol in the blood.
Products richest in dietary fiber (in g / 100 g of product) are
- wheat bran
- dried apricots
- dried apples
- Barley flakes
- wholemeal rye bread
- Sunflower seeds
- broad beans
- Rye bread
Demand for fiber for a healthy adult person is depending on the source from 20 to 40 g per day. The amounts of 20 g should not exceed children and adolescents up to 18 years, as well as patients during convalescence and with intestinal disorders (tendencies to spasticity and diarrhea, irritable bowel syndrome).
Dietary fiber – what to look for
First of all, if you have not used a diet rich in fiber so far, increase its amount gradually. Start with the introduction of rye, wholegrain bread, increase the supply of pods and vegetables and fruits. If you do not feel discomfort from the digestive system after making these changes, you can easily add bran and dried fruits to your diet. It should be remembered that any increase in the amount of dietary fiber in the diet requires increasing the amount of water consumed. Otherwise, the fiber may be irritating – cause painful bloating and constipation. The disruption of the absorption of some minerals may also be a negative aspect of fiber activity. Especially lignins, in large quantities, affect the reduced absorption of calcium, iron, zinc and magnesium from food.So if you suffer from nutritional deficiencies, try to limit fiber intake along with foods rich in these minerals.