Fiber. People need to eat it. They know it's good for them. But they may not know what it is and why it is so good.
Fiber is found only in plants. The plant fiber that we eat is called dietary fiber. It is unique from other parts of the plant because humans do not have the enzymes needed to digest it.
Dietary fiber is made up of two types of fiber: soluble and insoluble. Both types of fiber help the bowels regular.
Soluble means that the fiber forms a gel-like solution when it is mixed with a liquid. When eaten as part of a low-fat, low-cholesterol diet, soluble fiber can help lower cholesterol and may help lower the risk of heart disease. Oatmeal, beans, peas, and citrus fruits are all foods that are high in soluble fiber.
Insoluble fiber does not mix with liquid and passes through the digestive tract without changing. It is important for digestive health. It speeds up movement through the small intestine and helps to ease constipation. Apple skin, wheat cereal, whole-wheat breads, and carrots are all foods that are high in insoluble fiber.
How Much Fiber Is Needed
The Academy of Nutrition and Dietetics recommends that women get 25 grams of fiber daily, while men get 38 grams. Fiber needs drop after the age of 50. Women older than 50 should get 21 grams of fiber daily, and men should get 30 grams daily. This includes both soluble and insoluble fiber. This table lists how much fiber a person can find in some common foods.
|Soluble Fiber||Insoluble Fiber|
|Broccoli, cooked||½ cup||1.5||1||0.5|
|Brussels sprouts, cooked||½ cup||4.5||3.0||1.5|
|Carrots, cooked||½ cup||2.5||1||1.4|
|Artichoke, fresh||½ cup||4||3||1|
|Citrus fruit (orange, grapefruit)||1 medium||2-3||1||1-2|
|Black beans, cooked||½ cup||5.5||2||3.5|
|Kidney beans, cooked||½ cup||6||3||3|
|Lima beans, cooked||½ cup||6.5||3.5||3|
|Navy beans, cooked||½ cup||6||2||4|
|Northern beans, cooked||½ cup||5.5||5||0.5|
|Pinto beans, cooked||½ cup||7||2||5|
|Lentils, cooked||½ cup||8||1||7|
|Peas, cooked||½ cup||6||1||5|
|Whole grain cereals|
|All Bran cereal||1/3 cup||8||0.7||7.3|
|Oatmeal, cooked||½ cup||2||1||1|
|Oat bran||½ cup||3||2||1|
|Shredded wheat||2/3 cup||3||0.3||2.7|
|Wheat germ||2/3 cup||8||1||7|
|Pearl barley, cooked||½ cup||5||2||3|
|Brown rice||½ cup||4||0.5||3.5|
|Psyllium seeds||1 tablespoon||6||5||1|
Source: Journal of Family Practice. 2006;9:761-769
Ways to Get More Fiber
It is easy to increase the fiber in a person's diet. It just takes a little thought and some action. Here are a few ideas to help a person get more fiber:
- Try a whole grain cereal that has at least 5 grams of fiber per serving. Slice a banana on top, or add some raisins or berries to increase the fiber even more.
- Sprinkle a few teaspoons of wheat germ, ground psyllium, or ground flaxseed on food.
- Try eating some raw veggies or lightly steam them. Cooking can break down some of the fiber content.
- Leave the skin on fruits and veggies. Just make sure to rinse them with warm water to remove any dirt or bacteria.
- Eat the whole fruit or veggie instead of drinking the juice made from it. Juice does not use the skin or membrane of the fruit or veggie. This greatly lowers the fiber content.
- People should add whole, unprocessed grain to their diets. Substitute brown rice for white rice. Or choose whole wheat bread or pasta.
- Add beans to soups, salads, and stews. Throw some beans on top of a salad or add lentils to soup while cooking.
- Snack on fresh and dried fruit. Eat some raisins or dried apricots in the afternoon, instead of a bag of potato chips or pretzels.
Choose My Plate—US Department of Agriculture
Eat Right—Academy of Nutrition and Dietetics
Dietary considerations for cardiovascular disease risk reduction. EBSCO DynaMed website. Available at:https://www.dynamed.com/prevention/dietary-considerations-for-cardiovascular-disease-risk-reduction. Accessed August 26, 2020.
Dietary guidelines for Americans 2015-2020. Office of Disease Prevention and Health Promotion website. Available at: https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines. Accessed August 31, 2020.
Eat 3 or more whole grain foods every day. American Heart Association website. Available at: http://www.heart.org/HEARTORG/GettingHealthy/WeightManagement/LosingWeight/Eat-3-or-More-Whole-Grain-Foods-Every-Day_UCM_320264_Article.jsp. Accessed September 1, 2020.
Whole grains, refined grains, and dietary fiber. American Heart Association website. Available at: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyDietGoals/Whole-Grains-and-Fiber_UCM_303249_Article.jsp. Accessed September 1, 2020.
Last reviewed March 2020 by EBSCO Medical Review BoardDianne Scheinberg Rishikof MS, RD, LDN Last Updated: 3/3/2021