Fiber Overview

photo source: http://healthguide.howstuffworks.com/sources-of-fiber-picture.htm

It seems like everywhere you look, you hear something about fiber. Whether it's being promoted as good for heart health or losing weight, there is something to all the hype about fiber.

According ehealthMD, "Fiber is a virtually indigestible substance that is found mainly in the outer layers of plants. Fiber is a special type of carbohydrate that passes through the human digestive system virtually unchanged, without being broken down into nutrients."

It goes on to say that, "Fiber is important because it has an influence on the digestion process from start to finish." It helps to keep blood sugar at a steady level, instead of causing it to spike and then crash, like other carbohydrates.

There are two types of fiber: soluble and insoluble.

According to HealthCastle.com, both types of fiber are undigested (therefore, are not absorbed into the bloodstream). However, insoluble fiber passes through our bodies mostly intact, and soluble fiber does not.

The main functions of insoluble fiber are to, "move bulk through the intestines," and to, "control and balance the pH (acidity) in the intestines." Insoluble fiber helps prevent constipation, and helps move toxic waste through the colon more quickly.

Some sources of insoluble fiber are: green leafy vegetables, fruit and vegetable skins, whole-wheat products, and seeds and nuts.

The main functions of soluble fiber are to, "bind with fatty acids," and to, "prolong stomach emptying time so that sugar is released and absorbed more slowly." Soluble fiber helps to lower total cholesterol (reducing risk of heart disease), and it also helps regulate blood sugar for people with diabetes.

Some sources of soluble fiber are: oats, dried beans and peas, nuts, flax seed, and some fruits and vegetables.

And according to ehealthMD, a good diet should include 25-30 grams of fiber per day.

Sources:
http://www.ehealthmd.com/library/fiber/FIB_whatis.html
http://www.healthcastle.com/fiber-solubleinsoluble.shtml

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