Carbohydrates the Body Can't Digest

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Most of the benefits you get from the foods you eat come from the nutrients your body is able to digest and absorb. You wouldn't be able to function well if your body couldn't digest the fruits and vegetables you eat to absorb the vitamins and minerals they contain. However, although some parts of the carbohydrates you eat are not digested in the human body, these compounds can still have a beneficial effect on your health from your intestines.


Grains, sugars, starchy vegetables, fruits and some dairy provide most of the calories the majority of Americans consume through the carbohydrates they contain. Carbohydrates include different types of sugars, starches and fibers. For example, sucrose is the sugar mostly found in table sugar and lactose is the natural sugar found in dairy and fructose. Starches are made of sugar units bonded to one another and are mostly found in breads, pasta, rice, potatoes, beans and lentils.

Digestible Vs. Undigestible

The body can digest sugars and starches very well by using enzymes to break down these carbohydrates into very small molecules of sugar, called glucose. The glucose obtained from the digestion of starchy and sugary foods is easily absorbed into your blood and available to your cells as a source of energy. Fiber, on the other, cannot be digested by the human body. Because fiber is not digested, it stays in your gastrointestinal tract until it is eliminated in your feces.

Sources of Fiber

Indigestible carbohydrates, or fiber, are found in whole grains, legumes, fruits, vegetables, nuts and seeds. There are two different types of fiber present in these foods, which are called soluble or insoluble. For example, whole grains mainly contain insoluble fiber, while fruits, vegetables, nuts, seeds and legumes contain a mixture of varying proportions of soluble and insoluble fiber. Although neither of these types of fiber are digested, they have different properties and influence your health differently.

Fiber and Your Health

Even though your body cannot digest fiber, these carbohydrates can benefit your health. Insoluble fiber contributes to preventing constipation by giving bulk to your stools and helping get things moving in your intestines. Soluble fiber also helps prevent constipation by keeping your stools from becoming too dry. Moreover, soluble fiber can help lower your blood cholesterol levels and stabilize your blood sugar levels. Both types of these indigestible carbohydrates can help you achieve and maintain a healthier weight by helping you feel fuller with fewer calories. The Institute of Medicine recommends that adults consume between 25 and 38 grams of fiber a day.