Dietary fiber, similar to starches and sugars, is a type of carbohydrate. It cannot be digested by the human body so it does not contribute any calories to the diet. There are two types of fiber: soluble and insoluble; they both play a valuable role in health.
Soluble fiber slows down digestion, preventing a sharp increase in blood sugar and promoting satiety after meal; therefore, it plays a big role in blood glucose and weight control. Soluble fiber also helps lower blood cholesterol, which can decrease risk of heart disease.
Insoluble fiber speeds up the passage of food and waste through digestive tracts and increases stool bulk, which helps prevent constipation and colon cancer.
Deficiency of dietary fiber in the modern diet is common due to increased consumption of highly processed food products. A low fiber diet can cause constipation, hemorrhoids and elevated cholesterol levels; however, if the intake remains persistently low, it can increase the risk of developing some life-threatening diseases, such as cardiovascular diseases, colon cancer and obesity.
Excessive of fiber intake is uncommon. A sudden increase in fiber intake may lead to cramping, diarrhea, and intestinal gas. Therefore, it is advised to gradually increase the fiber intake, as well as increase water intake, to minimize undesirable effects.
No less than 25g of dietary fiber per day is recommended.
Fiber Rich Foods
- Apple with skin ~ 4
- Whole wheat bread ~ 2
- ½ cup of cooked red beans ~ 8
(Source: Centre for Food Safety Nutrient Information Inquiry)SourcesWhole grains (e.g. brown rice, oatmeal, oat bran and wheat germ), beans (e.g. mung beans), nuts, seeds (e.g. black sesame seeds), fruit (with skin), and dark green leafy vegetables. Many foods such as oat and oat bran are rich in both insoluble and soluble fiber.