Dietary Fiber

Dietary fiber should be a very important part of our diet. Interestingly, fiber includes parts of plants that pass through our digestive system virtually unchanged, they can not be absorbed. The true importance of fiber occurs in situation, when we do no have sufficient daily income, which is typical for developed countries.

The importance of fiber

The importance is just in its indigestibility. Plenty of fiber increases stool volume and fiber also keeps water in the stool. Therefore, stool of a person with adequate fiber intake is more bulky and it is also thinner. Such stool better comes through the intestine, which does not have to work so hard. The result is frequent and regular stool. Thanks to this, food residues do not stay in the intestines, where they could transform into toxic substances. For example, toxic substances of protein metabolism such as cadaverine and putrescine may increase the risk of colon cancer. Therefore, dietary fiber is considered an important protective factor of colorectal cancer.


Since the stool is thin, the intestines do not need to use such an excessive compressive force to transport it towards the rectum. This is a great prevention of constipation and diverticulosis.


Dietary fiber is also able to bind cholesterol in the guts and so it may slightly decrease the cholesterol blood level and protects us from high cholesterol and its complications.

The recommended daily fiber intake

Minimal recommended daily fiber intake does not seem to be a high value - it is only 1 ounce (about 30 grams). Unfortunately, in the majority of sold food, there is only minimal presence of fiber. Higher doses of fiber (more than about 1.5 ounce per day) are not harmful, but they may increase the fiber's effect to such extent that we may begin to suffer from bloating and diarrhea. This is not pleasant and it may also cause dehydration.

Sources of fiber

Dietary fiber is found in legumes, whole grain breads, fruits and vegetables. Fiber may be added to other foodstuff, for example into yogurts.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources