Bulking Up on Fiber

by Mary Calvagna, MS [1]

Fiber: you know you need to eat it. You are pretty sure it is good for you. And according to reports, you, like many other Americans, aren't getting anywhere as much fiber as you should. But what is fiber, really? And why is it good for you?

Fiber Facts

Fiber is found only in plants. It is from the plant cells, particularly the cell walls. The plant fiber that we eat is called dietary fiber. It is unique from other components of the plant because humans lack the enzymes necessary to digest it.

Dietary fiber is made up of two types of fiber: soluble and insoluble. Soluble means that when the fiber is mixed with a liquid, it forms a gel-like solution. Insoluble fiber does not mix with liquid and passes through the digestive [2] tract largely intact. Both types of fiber help maintain bowel regularity.

Soluble fiber

Soluble fiber has been found to provide some additional health [3] benefits. When eaten as part of a low-fat, low-cholesterol diet, soluble fiber can help lower blood cholesterol [4]. Weaker and somewhat inconsistent evidence hints at a link between soluble fiber intake and a reduced risk of certain cancers, diabetes [5], digestive [2] disorders, and heart [6] disease. Foods high in soluble fiber include oat bran, oatmeal, beans, peas, rice bran, barley, citrus fruit (the whole fruit, not the juice), strawberries, apples, and psyllium.

Insoluble fiber

Although insoluble fiber has not been shown to lower blood cholesterol [4], it is important for normal digestive [2] health [3]. Insoluble fiber speeds up movement through the small intestine and helps to alleviate constipation. Foods that are high in insoluble fiber include whole wheat breads, wheat bran, rye, rice, barley, and most other grains, as well as cabbage, carrots, and cauliflower.

How Much Fiber Do I Need?

Health experts recommend eating a minimum of 20 to 30 grams of fiber daily. This includes both soluble and insoluble fiber. Most Americans eat about 11 to 15 grams a day—about half of what is recommended. The following table lists some foods that are high in fiber.

Food	Serving size	Fiber (grams)
Grains, Beans, and Nuts
Lentils	½ cup	7.8
Black beans	½ cup	7.7
Kidney beans	½ cup	7.3
Wheat germ	½ cup	7.3
Peanuts	½ cup	5.8
Kellogg's Bran Flakes	1 cup	5.5
Garbanzo beans (chickpeas)	½ cup	5.3
Oatmeal, cooked	1 cup	4.0
Bran muffin	1 medium	2.5
Bread, whole wheat	1 slice	1.5
Vegetables
Potato, baked with skin	1 medium	4.8
Peas, cooked	½ cup	4.4
Sweet potato, baked with skin	1 medium	3.4
Brussels sprouts, cooked	½ cup	3.4
Spinach, cooked	½ cup	2.8
Broccoli, cooked	½ cup	2.3
Potato, baked without skin	1 medium	2.3
Carrot	1 medium	2.2
Corn, cooked	½ cup	2.0
Cauliflower, cooked	½ cup	1.7
Fruits
Pear	1 medium	4.0
Apple, with skin	1 medium	3.7
Orange	1 medium	3.1
Banana	1 medium	2.7
Nectarine	1 medium	2.2
Cantaloupe	½ medium	2.1
Prunes, dried	10 pieces	1.8
Peach	1 medium	1.7
Strawberries	½ cup	1.7

Increasing Fiber in Your Diet

It is easy to increase the fiber in your diet—it just takes a little thought and some action. Here are a few ideas to help you get on track to 30 grams of fiber a day.

Try a whole grain cereal that contains 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 or ground psyllium on your meals before eating.
Try eating some vegetables raw. Cooking can break down some of the fiber content. If you do cook vegetables, steam them lightly, so they are tender but still firm.
Leave the skin on fruits and vegetables. Just make sure you rinse them well with warm water to remove any dirt or bacteria.
Eat the whole fruit or vegetable instead of drinking the juice made from it. Juice does not contain the skin or membrane of the fruit or vegetable, and therefore its fiber content is substantially reduced.
Try adding whole, unprocessed grain to your diet. Substitute brown rice, bulgar, kasha, or couscous for white rice. Or opt for whole wheat bread or pasta.
Add beans to your soups, salads, and stews. Throw some garbanzo beans on top of a salad or add lentils to soup while cooking.
Snack on fresh and dried fruit. Chomp some raisins or dried apricots in the afternoon, instead of a bag of potato chips or pretzels.

A Word of Caution...

When you begin to increase the fiber in your diet, take it slow. Increasing too quickly can upset your intestinal tract and you may experience gas, bloating, cramps, or even constipation or diarrhea. By increasing your fiber intake just a few grams a day, your intestinal tract will have time to adjust. Other tips to help minimize upset include:

Drink at least eight 8-ounce cups of water a day.
Use enzyme products, such as Beano, to help you digest fiber.
Don't cook dried beans in the same water in which you soaked them.

Click here for fabulous fiber recipes [7].

RESOURCES:

American Dietetic Association
http://www.eatright.org [8]

My Pyramid - United States Department of Agriculture
http://www.mypyramid.gov/ [9]

CANADIAN RESOURCES:

Canadian Council on Food and Nutrition
www.ccfn.ca [10]

Dietitians of Canada
http://www.dietitians.ca/ [11]

Last reviewed January 2008 by Rosalyn Carson-DeWitt, MD [12]

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical [13] advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health [3] provider prior to starting any new treatment or with any questions you may have regarding a medical [13] condition.