Insoluble fibers have the main benefit of improving intestinal transit and fighting constipation because they increase stool volume and stimulate peristaltic movements, causing food to pass more quickly and more easily through the intestine.
Unlike soluble fibers, the insolubles do not absorb water, and pass through the stomach without alterations. They are mainly present in foods such as wheat bran, brown rice, beans and whole grain cereals.
Thus, the main benefits of insoluble fibers are:
- Maintain regular bowel movement and fight constipation;
- Prevent hemorrhoids, by facilitating the elimination of feces;
- Prevent colon cancer by retaining toxic substances that are ingested;
- Reduce the contact of the intestine with toxic substances, by making them pass more quickly through the intestine;
- Help to lose weight, to give greater satiety and to delay the sensation of hunger.
The total daily fiber recommendation, which includes soluble and insoluble fiber, is 25g for adult women and 38g for adult men.
Foods rich in insoluble fibers
The following table shows the main foods rich in insoluble fibers and the amount of fibers per 100 g of food.
| Food | Insoluble Fibers | Soluble Fibers |
| Almonds in shell | 8.6 g | 0.2 g |
| Peanut | 6.6 g | 0.2 g |
| Green olive | 6.2 g | 0.2 g |
| Grated coconut | 6.2 g | 0.4 g |
| Walnuts | 3.7 g | 0.1 g |
| You pass | 3.6 g | 0.6 g |
| Avocado | 2.6 g | 1.3 g |
| Black grape | 2.4 g | 0.3 g |
| Pear with peel | 2.4 g | 0.4 g |
| Apple with peel | 1.8 g | 0.2 g |
| Strawberry | 1.4 g | 0.4 g |
| Tangerine | 1.4 g | 0.4 g |
| Orange | 1.4 g | 0.3 g |
| Peach | 1.3 g | 0.5 g |
| Banana | 1.2 g | 0.5 g |
| Green grape | 0.9 g | 0.1 g |
| Plum with peel | 0.8 g | 0.4 g |
In addition to these foods, regularly consuming fruits with bark and bagasse, and vegetables in general is important to provide a good amount of fiber in the diet and get the benefits of that nutrient. See the amount of fiber in other foods in Benefits of Soluble Fibers.
Fiber Supplements
In some cases of chronic constipation or even diarrhea, it may be necessary to use fiber-based supplements that will help regulate intestinal transit. These supplements can be found in supermarkets, pharmacies, and nutritional stores, and are usually presented in the form of capsules or powders to be diluted in water, tea or juice.
Some examples of fiber supplements are FiberMais, Glicofiber, Fibermais Flora and Fiberlift, being important to remember that they should only be used with the advice of the nutritionist or the doctor.
To help improve bowel function, see also How to cure constipation.
