Dietary fiber, also known as roughage and bulk, is a complex carbohydrate found in fruits, vegetables, legumes, nuts, and grains, that cannot be broken down by your body during digestion. If your body cannot process it, why is fiber so important to health? Fiber aids digestion, reducing the chances of constipation and hemorrhoids, and it may help deter heart disease and certain cancers. When whittling your waistline is the goal, fiber is particularly helpful because it makes you feel full and that full feeling lasts longer. Plus fiber’s capacity to provide bulk in your stomach makes it difficult to overeat fiber-rich foods, as compared to low-fiber, highly refined alternatives. For example, it’s a lot easier and quicker to drink 8 ounces of apple juice, which is refined and low in fiber, than it is to eat two whole apples, although the juice and the apples have an equivalent number of calories.
Foods high in fiber are typically low in natural and added sugars, making them perfect choices for low-carb living. In fact, many low-carb diet proponents recommend choosing foods rich in fiber because fiber slows down the release of glucose into the bloodstream, preventing insulin surges that may result in weight gain. Fiber-filled foods are also rich in several vital nutrients, including vitamins, minerals, and phytonutrients, plant substances that may guard against heart disease and cancer.
Fiber, Cholesterol and Gas
Insoluble fiber is found in wheat, rye, bran, and other grains.
It is also the fiber found in most vegetables. Insoluble fiber means it does not dissolve in water. It also cannot be used by intestinal-colon bacteria as a food source, so these beneficial bacteria generally do not grow and produce intestinal gas.
Soluble fiber, on the other hand, does dissolve in water forming a gelatinous substance in the bowel. Soluble fiber is found in oatmeal, oat bran, fruit, psyllium (Metamucil, Konsyl), barley, and legumes. Soluble fiber, among its other benefits, seems to bind up cholesterol allowing it to be eliminated with the stool. If enough is removed it can lower the blood cholesterol 10-15%.
The down side of soluble fiber is that it can be metabolized by gas forming bacteria in the colon. These bacteria are harmless but for those who have an intestinal gas or flatus problem it is probably best to avoid or carefully test soluble fibers to see if they are contributing to intestinal gas. Whenever possible, both soluble and insoluble fiber should be eaten on a daily basis.