Debbie J., MS, RD contributed this article –
Fiber is the indigestible portion of plant carbohydrate. Think of it as a lock between the sugar bonds that our digestive enzymes can’t break. This is good news for you x4! Fiber has fewer calories (since you can’t burn the bonded sugar units for energy), it is bulky enough to take up room in your stomach limiting caloric food, it has more roughage to keep your gut muscles healthy, and it has something to feed your colonic bacteria. Yes, that’s actually a good one.
There are 2 main types of dietary fiber – soluble and insoluble, referring to their interaction with water. You need both for the best benefit. Edible plants have a combination of both types of fiber, yet some offer more of one than the other. Soluble fibers are mainly found in foods like oatmeal, apples, legumes, berries, and cucumber while insoluble fibers are mainly found in foods like whole grains, bran, seeds, broccoli, carrots, and raisins.
Why it matters what fiber you are eating… Soluble fiber has the benefits of slowing digestion to blunt the rise in blood sugar, give bulk to your stool and help reduce cholesterol. Insoluble fiber has the benefit of speeding up transit time to improve clearing of toxic waste, assist in elimination, and prevent constipation. Both serve as ‘food’ for the healthy microbes that live in our colon, thus they are prebiotic. The bacteria ferments the fiber creating metabolites that result in an array of health benefits elsewhere in the body.
To support a trim waistline and help prevent disease, you should aim for 10 grams fiber for every 1000 calories you consume. A reference diet of 2500 calories should include at least 25 grams of dietary fiber.