Kootenai | Kootenai Health | Issue 4, 2023

16 By Kim Anderson We’ve all heard that adding fiber to our diets is a good thing. What isn’t talked about as often is the fact that there are different types of fiber and how each benefits the body in different ways. Knowing the differences and how each type works can help guide your choices and make a world of difference in your health. Insoluble fiber Insoluble fiber does not dissolve in water and will pass through the stomach and intestines (gastrointestinal, or GI, system) relatively intact. Insoluble fiber is not a source of calories because the body does not have the enzymes needed to break it down. It is important to recognize that the degree of processing (fine The Finer Points of Fiber vs. coarse particles) determines the effect of insoluble fiber on constipation. For example, coarse wheat bran particles can stimulate fluid secretion from the colon and relieve constipation. However, when finely ground, small particles of the same wheat bran no longer stimulate fluid secretion in the colon and the effect in treating constipation is lost. This is one reason why highly processed foods are typically less beneficial compared with more natural foods, even if the label advertises fiber content. Soluble fiber Soluble fiber can also treat constipation, but it does so in a different way, by attracting water and keeping it in the colon to soften stool. The most effective fibers for treating constipation, such as psyllium, found in Metamucil, work in this way—by holding on to water. This is why fluid intake is so important. “If you are going to increase fiber, you must also increase fluids,” said Leslie Wall, RD, LDN, CNSC, Kootenai Health registered dietitian and manager of clinical nutrition. “Too much fiber and not enough fluids can actually worsen GI symptoms, so increasing fluids along with fiber is very important.” Soluble fiber attracts water and turns to a gel during digestion. One benefit of soluble fiber is in slowing digestion and the rate at which carbohydrates and other nutrients are absorbed in the bloodstream. Slower absorption can help control the level of blood glucose, often referred to as blood sugar, and prevent rapid rises, or “spikes,” in blood glucose following a meal. What to know about this mighty material before adding more to your diet