Dietary fiber is a type of insoluble carbohydrates and is not affected by digestion. Since it is indigestible in nature it is not absorbed readily in to the circulation. Thus in spite of being a carbohydrate, it does not appear in the blood stream. The major examples of fiber in the diet include the cellulose, hemi cellulose and pectin. These are commonly found in skins of fruits, coverings of seeds, and edible parts of plants. Pectin has the property to form gels and this is made use of in the preparation of jams and jellies.

Types of fiber:

The dietary fiber is not digested by enzymatic reactions. Dietary fiber could be broadly classified into two types namely, those that are soluble in water and those that are insoluble in water. The insoluble fibers include cellulose, hemi cellulose and lignin that are found in wheat bran, whole wheat, vegetables, nuts and seeds. The soluble fibers include pectin, gums and mucilage and are found in fruits, oats, barley, legumes and beans.

Functions of fiber in the body:

The fibers are not affected by enzymatic reactions and are hence not digested in the gastro intestinal tract and absorbed in the body. Fibers could be used as a source of food that induces the feeling of satiety by providing dietary bulk. Thus a feeling of fullness is provoked in the humans and results in reduced consumption of calorie rich foods, thereby reducing the body weight. Reduced consumption of calories does not mean deficient intake of food because fiber being indigestible in nature, stays in the intestine for a longer period of time. Thus the feeling of hunger is reduced.

The water absorbing capacity of the fiber is made use of in the excretory function of the body. The waste products that are accumulated as a result of metabolic reactions in the body are eliminated from the body by binding with the fiber. Also, fiber is found as an agent that helps to induce the peristaltic movements and thus aids in the removal of wastes products from the body.

Fiber has the capacity to bind the nutrients present in the food. This capacity is sometimes beneficial, but mostly harmful. When fiber combines with the cholesterol that is harmful to the body, it acts as a protecting factor. But when the binding effect is discussed with respect to nutrients such as calcium, iron, and zinc, it highlights the harmful effects of fiber. The components that fiber binds are excreted.

Lack of adequate dietary fiber in the daily diet of an individual leads to difficulty in elimination of wastes from the body. Consistent shortage of fiber in the diet leads to severe constipation and this condition could be corrected by taking more of fiber. Intake of more fiber also improves the water absorptive capacity and thus results in the formation of soft stools. Diabetics are recommended to consume more of fiber rich foods because it binds with the carbohydrates in the diet and prevents the blood sugar level from rising remarkably. Fiber is also capable of binding with cholesterol and thus protecting the body from the occurrence of heart diseases.

The recommended daily intake of dietary fiber should be 25 grams per day.

Are we consuming this recommended allowance of fiber in our daily diet?

If not, we are susceptible to be affected by diseases like constipation, heart disease, obesity and so on, which are considered as the major health threats in our present scenario.

It is very simple to increase our dietary intake level of fiber by consuming the fiber rich foods. The foods that are very good sources of fiber include whole wheat, whole wheat flour, wheat bran, brown rice, oats, skin of bananas and other fruits, vegetables. This could be achieved by incorporating more of whole wheat instead of refined items, taking raw fruits instead of fruit juices and cool drinks, consuming oats and intake of more fiber rich foods.

Fiber, if taken in larger quantities is also not beneficial to the body. It causes intestinal obstruction if adequate amounts of water are not consumed regularly. A sudden increase in the fiber content of the diet also could result in conditions such as hemorrhoids, cramping, diarrhea and excessive intestinal gas. In order to minimize these effects, the fiber content of the diet should be gradually increased.