Fiber is the indigestible carbohydrate found in plant foods, including grains, fruits, vegetables and nuts and seeds. There are two different types of fiber. Insoluble fiber adds bulk to your stool and helps it move quicker through the digestive system. It will prevent constipation and may also help prevent colon cancer. Soluble fiber is turned into a gel during digestion, which helps make stool softer, and, thus, easier to pass. Soluble fiber is beneficial for lowering cholesterol and absorbing bile salts and glucose. The recommended daily amount of fiber is 25 grams for women and 38 grams for men. After age 50, daily requirements are 21 grams for women and 30 grams for men.
Legumes, which include beans, peas and lentils, pack more fiber per serving than any other vegetable. One-half cup of cooked lentils contains 8 grams of fiber and 1/2 cup of lima beans contains 7 grams of fiber. One-half cup of kidney beans and navy beans each contain 6 grams of fiber.
Berries are very high in fiber and can significantly increase your daily fiber intake. One cup of raspberries and 1 cup of blackberries contain 8 grams of fiber each. One cup of strawberries and 1 cup of blueberries each provide approximately 4 grams of fiber. Blend berries into a smoothie or pile them on top of yogurt for a sweet, high-fiber snack.
Nuts and Seeds
Nuts and seeds are healthy sources of dietary fiber. One-fourth cup of almonds provides 4 grams of dietary fiber and 1/4 cup of Brazil nuts will provide 3 grams. One tablespoon of ground flaxseeds has 2 grams of fiber, and 1/2 tablespoon of chia seeds provides approximately 5.5 grams. Nuts and seeds are rich in monounsaturated fatty acids, which are known for promoting heart health.
Grains contain three components: the bran, germ and endosperm. The bran portion of the grain is what contains most of the fiber. Refined grains have a lower fiber content than whole grains because the bran is removed. Choose whole grains such as 100-percent whole-grain bread; whole-grain cereals such as oatmeal; whole-grain crackers and pasta; and brown rice. One-half cup of bran flakes contains approximately 8 grams of fiber.
Both raw and cooked vegetables will provide a generous dose of fiber to your diet. One cup of boiled broccoli contains 5 grams of dietary fiber while the same amount of Brussels sprouts will provide 4 grams. One cup of cooked green peas will provide nearly 9 grams of fiber.
Lindsey Lankowsky is a registered dietitian based in Los Angeles. She holds a Bachelor of Science in dietetics from Michigan State University and a Master of Science in nutrition from Case Western Reserve University. Lankowsky has worked in the Veterans Health Administration since 2009 and has written various nutrition articles for the VA.