Photo credit: Nick Mote, Flickr Creative Commons
Most of us know that fiber is important to good health, but do you know if you are getting enough and what foods provide you with fiber? According to the U.S. Department of Agriculture's 2015 Dietary Guidelines for Americans, plant foods like fruits, vegetables, whole grains, nuts, seeds, dried beans, peas, and legumes are our major sources of fiber. It is recommended that we eat more of these foods that provide dietary fiber.
Dietary fiber, also known as roughage or bulk, is a form of carbohydrate that includes the parts of the plant your body can't digest or absorb. Fiber is classified as soluble, which means it dissolves in water, or insoluble, which means it doesn't dissolve. Soluble fiber is found in beans, peas, lentils, oatmeal, barley, nuts, seeds, psyllium, apples, citrus fruits, and carrots. This type of fiber is linked to lowering LDL cholesterol, regulating blood sugar, and reducing the risk of heart disease and type 2 diabetes. Insoluble fiber helps keep your bowels working regularly and prevent constipation, and it lowers the chance of getting diverticular disease. Sources include whole grains, barley, bulgur, nuts, seeds, beans, carrots, zucchini, dark leafy vegetables, grapes, and tomatoes. Most plant-based foods, such as oatmeal and beans, contain both soluble and insoluble fiber, so it is important to eat a variety of high-fiber foods.
In addition to helping maintain bowel and heart health, other benefits to the body include reducing blood pressure and inflammation, helping control blood sugar levels by slowing the absorption of sugar, and helping achieve a healthy weight. Because our bodies cannot digest fiber, high-fiber foods are more filling and you are more likely to eat less and stay satisfied longer. High-fiber foods take longer to eat and are less "energy dense," which means they have fewer calories for the same volume of food. There is also some evidence that fiber is linked to a lower risk of certain cancers, such as colorectal cancer.
Tip: Read labels for fiber content. An excellent source of fiber has 5 or more grams of fiber per serving. A good source of has 2.5 to 4.9 grams of fiber per serving.
Whole-plant foods are the best way to obtain fiber because they are naturally rich in vitamins, minerals and other beneficial nutrients. So consuming the skin, seeds, or stems of fruits and vegetables, if possible, is necessary to provide fiber. Refined or processed grains, such as white breads and pastas, non-whole-grain cereals, and white rice, are very low in fiber. The grain-refining process removes the outer layer or bran from the grain, which lowers its fiber content. Enriched foods do have some of the B vitamins and iron added back in, but they do not have the fiber.
Adding Fiber to Your Diet
The best way to get more fiber in your diet is to start replacing low-fiber carbohydrates and other foods with foods that are higher in fiber. You can begin by making some simple changes when grocery shopping. Check the Nutrition Facts label. A food that is a good source of fiber will have a daily value of 10 to 20 percent or more for fiber in a oneounce serving. Here are a few ways to add more fiber to your diet:
- Switch to whole grains. Consume at least half of all grains as whole grains (3 servings). Look for breads that list whole wheat, whole-wheat flour, or another whole grain as the first ingredient on the label and have at least 2 to 3 grams of dietary fiber per serving. Substitute whole-grain pasta for that made with white flour. Substitute brown rice for white rice. Try some different grains like quinoa, bulgur, and barley.
- Eat beans a few times a week in place of your usual choice of chicken or beef protein choices. Add them to soups, stews, salads, chili, and Mexican dishes.
- Eat enough fruits and vegetables. The current daily recommendation is about 4½ cups, which is about 1½ cups or half a plate at each meal. These are rich in fiber and loaded with vitamins and minerals.
- Choose whole-grain cereal in place of bagels and bakery treats for breakfast. Aim for that cereal having 5 or more grams of fiber per serving. Look at the ingredient list to be sure the whole grain (such as whole wheat, whole oats, and whole corn) is the first on the list. Add a few tablespoons of unprocessed wheat bran to your favorite cereal for an added boost.
- Top your salad with toasted nuts instead of croutons.
- In baked goods, substitute whole-grain flour for half or all of the white flour when baking. Add crushed bran cereal, unprocessed wheat bran, or uncooked oatmeal to muffins, cakes, and cookies.
- In your snack choices, concentrate on eating high-fiber foods. Fresh fruits, raw vegetables, low-fat popcorn, and whole-grain crackers are all good choices. Nuts, seeds, or dried fruits are also healthy, high-fiber snacks, but they are high in calories.
Just remember, easy does it. If your fiber intake has been low, you should add dietary fiber gradually to avoid discomfort. This allows the natural bacteria in your digestive system to adjust to the change. To balance the fiber, also increase the amount of water you're drinking. Take your time so that your body can get used to the new eating pattern. Add about 5 grams of fiber per day, spread throughout the day, until you reach your goal.
Tips Affecting Different Age Groups
How Much Fiber Do We Need?
|Ages 1-6||Ages 8-13||Ages 14+ (females)||Ages 14+ (males)|
|14-16 grams||22-25 grams||22-28 grams||28-33 grams|
Examine Your Choices
|Food||Source||What I buy||What I plan to buy/change|
|Grains||Dietary fiber||Enriched white bread||Whole-grain bread|
|Cereal||Dietary fiber||Sugary, Low-fiber Cereal||Oatmeal or Shredded Wheat|
Serving size: 2 burritos
- 1 16-ounce can of pinto beans
- 1 Tablespoon canola oil
- 1 package (10) whole grain flour tortillas
- ½ cup chopped onions
- 1 cup grated 2% American or Longhorn cheese
- Chopped lettuce
- Salsa or taco sauce
Mash drained beans and heat in oil until hot. Simmer and stir over low heat until thick. Heat flour tortillas until warm and soft. Spread about 2 Tablespoons of beans on the tortilla. Add cheese, onions, lettuce, and salsa if desired. Fold one side of the tortilla up about one inch, and then roll. Makes 5 servings.
One serving (two burritos): 300 calories, 17 g protein, 6 g fat, 1 g saturated fat, 56 g carbohydrate, 9 g fiber, 8 mg cholesterol, 888 mg sodium, 208 mg calcium, 3 mg iron, 464 IU vitamin A.
Academy of Nutrition and Dietetics. "Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber." J Acad Nutr Diet 115, no. 11 (2015): 1861-1870.
Food and Nutrition Board, Institute of Medicine, National Academies. "Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients." 2005.
Kaczmarczyk, M. M., Miller, M. J., and Freund, G. G. "The Health Benefits of Dietary Fiber: Beyond the Usual Suspects of Type 2 Diabetes, Cardiovascular Disease and Colon Cancer." Metabolism 61, no. 8 (2012): 1058-1066.
Kohn, J. "Is Dietary Fiber Considered an Essential Nutrient?" Academy of Nutrition and Dietetics, March 2016.
Mayo Clinic. "Dietary Fiber: Essential for a Healthy Diet." Sept. 22, 2015.
U.S. Department of Agriculture. "Dietary Guidelines for Americans, 2015-2020."
Prepared by Nancy Yergin, former Penn State Extension Educator. Updated in 2016 by Nancy Routch, extension educator.