Dietary fibers are the indigestible portion of plant foods that move food through the digestive system and consists of non-starch polysaccharides such as cellulose and many other plant components such as dextrins, lignin, waxes, and oligosaccharides. Fibre is present in all plants that are eaten for food, including fruits, vegetables, grains, and legumes. They are important constituents of a healthy diet and have wide ranging benefits.
There are two kinds of dietary fibre namely soluble and insoluble fibre and both offer distinctive advantages. Some foods containing soluble fibre include beans, banana and apples. One of its major roles is to lower blood cholesterol levels. Foods containing insoluble fibre includes tomatoes, oranges, kontomire, cabbage, lettuce, rice and carrots. A major role of insoluble fibre is to add bulk to faeces and to prevent constipation.
Regular fibre intake has been linked with a reduction in risk of developing heart diseases. Coronary heart disease is a leading cause of death for both men and women and is characterized by a buildup of cholesterol-filled plaque in the arteries that feed the heart. This causes them to become hard and narrow and a total blockage of a coronary artery produces a heart attack.
Fibre intake is also beneficial to people suffering from type 2 diabetes which is characterized by sustained high blood sugar levels. Regular intake of dietary fibre helps in the dietary management of diabetes because it reduces the overall calorie content of the diet and also contributes to weight loss in an indirect manner. Fibre rich foods such as beans, fruits and vegetables have a low glycemic index which means they do not raise blood sugar levels quickly and are appropriate for diabetics.
Fibre consumption also helps in the prevention and management of constipation. Constipation is a very common complaint and is of particular concern to the elderly.
For someone wanting to lose weight, dietary fibre can play a role. Fibre rich foods have bulk and are therefore satisfying. They also tend to be low in fat. Soluble fibre forms a gel that slows down the emptying of the stomach and the transit time of food through the digestive system. This extends the time a person feels satisfied and also delays the absorption of sugars from the intestines. This helps to maintain lower blood sugar levels and prevent a rapid rise in blood insulin levels, which has been linked with obesity. The extra chewing time often required of high fibre foods also helps contribute to feeling satisfied. As a result, a person on a high fibre diet is likely to eat less food and so consume less calories.
The best sources are fresh fruits and vegetables, nuts and legumes, and whole-grain foods. Some tips for increasing fiber intake include eating whole fruits instead of drinking fruit juices and snacking on fruits and vegetables instead of high fat/sugar snacks.
