Get the Facts on Fiber

Find out all the good things fiber can do for you

From the WebMD Archives

Getting enough fiber is something people don't think about all that often. Let's face it: Most of us haven't a clue how many grams of fiber we're taking in on a typical day.

And guess what? We're not even close to meeting the recommended intakes of 20-35 grams a day for healthy adults (25 daily grams for those eating 2,000 calories per day, for example, and 30 grams for 2,500 calories a day) according to the American Dietetic Association. The mean fiber intake in the U.S. is 14-15 grams a day.

We get fiber from unprocessed foods such as fruits, vegetables, whole grains, nuts, seeds, and beans, and most Americans aren't exactly loading their plates with these items. You'd be hard pressed to find any of them in your average fast-food value meal.

And Americans are definitely eating more prepared and processed foods. Consumption of food prepared away from home increased from 18% of our total calories to 32% of total calories between 1977 and 1996. All this "away" food not only has more calories and fat per meal than home-prepared foods, but also less fiber (on a per-calorie basis).

Why Do We Need Fiber?

It's hard to believe that something we can't even digest can be so good for us! A higher-fiber diet has been shown to lower blood cholesterol levels and prevent constipation. High-fiber foods also tend to contain more nutrients and fewer calories, are digested more slowly, and help us feel full sooner.

But that's only the beginning of fiber's story. Here's what else it may do for us:

  • The more gummy, gelatinous type of fiber (like that found in oats, breads, cereals, and the inside of kidney beans) lowers blood cholesterol levels and helps normalize blood glucose and insulin levels (important in preventing heart disease and type 2 diabetes).
  • The roughage type of fiber (like that found in wheat bran, strawberry seeds, and apple and bean skins) helps move things along in the large intestine. This promotes regular bowel movements and prevents constipation.
  • A recent review of studies indicated that a higher-carb, low-fat diet (including ADA-recommended amounts of fiber) may be beneficial for treating people with syndrome X, an insulin-resistant condition linked to obesity.
  • Fiber-rich foods help prevent diverticulosis. They help prevent the formation of intestinal pouches (diverticula) by contributing bulk in the colon, so that less forceful contractions are needed to move things along.
  • Fiber can reduce your risk of colorectal cancer. If people who normally get little fiber suddenly doubled their intake through wiser food choices, they could lower their risk of colon cancer by 40%, according to research involving data collected from 10 European countries.
  • Fiber (from whole grains, vegetables, and beans) may have protective effects against breast cancer.
  • High-fiber diets may help slow the epidemic of type 2 diabetes in the U.S., in part by enhancing insulin sensitivity. But it may not just be all about the fiber in this case; high-fiber foods also happen to be major sources of important micronutrients. That's why you want to concentrate on whole plant foods, not just fiber pills or supplements.

The 5 Quickest Ways To 25 Grams Of Fiber

Now that we all agree fiber benefits the body, how do we get more into our daily diets? Here are some painless ways to work in that fiber:

1. Get Those Whole Grains

  • 2 slices of whole wheat bread = 4 grams of fiber.
  • 1 cup of cooked brown rice = 4 grams of fiber.
  • 1/4 cup of whole-wheat flour, used in baking = 3 grams of fiber.
  • The next best thing to whole-wheat bread is fiber-enriched white bread (such as School Bus or Iron Kids). 2 slices = 3 grams of fiber.
  • 7 Reduced-Fat Triscuit crackers = 3 grams.

2. Choose High-Fiber Breakfast Cereals

  • 1 cup of Raisin Bran = 7.5 grams of fiber.
  • 1 cup of Quaker Squares Baked in Cinnamon = 5 grams.
  • 1 cup of Frosted Shredded Wheat Spoonsize = 5 grams.
  • 3/4 cup of cooked oatmeal = 3 grams of fiber.
  • 1 cup of cooked Cream of Wheat = 3 grams of fiber.
  • 1 cup of Multigrain Cheerios = 3 grams of fiber.
  • 1 cup of Wheaties = 3 grams of fiber.

3. Eat Beans a Few Times a Week

  • 1 cup of canned minestrone soup = about 5 grams.
  • 1/2 cup of vegetarian or fat-free refried beans, used to make easy microwave nachos = about 6 grams of fiber.
  • 1/4 cup of kidney beans, added to green salads = 3 grams of fiber.
  • A bean burrito at Taco Bell (or made at home) = 8 grams.

4. Work in Fruits Whenever You Can

Try to get several servings every day. Add fruit to your morning meal, enjoy it as a snack, and garnish your dinner plate with it. You can even have fruit with -- or instead of -- dessert!

  • 1 apple = 3.7 grams of fiber.
  • 1 banana = 2.8 grams of fiber.
  • 1 pear = 4 grams of fiber.
  • 1 cup of strawberries = 3.8 grams of fiber.

5. Work in Veggies Whenever You Can

Again, aim for several servings every day. Include a vegetable with lunch, have raw vegetables as an afternoon snack or pre-dinner appetizer, and enjoy a big helping with dinner. And make a point of having vegetarian entrees several times a week.

  • 1 cup of carrot slices, cooked = 5 grams of fiber.
  • 1 cup of cooked broccoli = 4.5 grams of fiber.
  • 1 cup of raw carrots = 4 grams of fiber.
  • 1 sweet potato = 4 grams of fiber.
  • 1 cup of cauliflower, cooked = 3 grams of fiber.
  • 2 cups of raw spinach leaves = 3 grams of fiber.

Show Sources

SOURCES: Journal of the American Dietetic Association, July 2002; vol 102. Journal of the American Dietetic Association, October 1997; vol 97. American Journal of Clinical Nutrition, March 2003; vol 77: pp 622-629. Journal of the American Dietetic Association, January 2003; vol 103. The Lancet, May 3, 2003; vol 361: pp 1491-1495, 1487-1488. American Journal of Medicine, Dec. 30, 2002; vol 113 Suppl 9B: pp 30S-37S. Journal of Women's Health, March 2003; vol 12: pp 115-122. Diabetes Care, July 2003; vol 26: pp 1979-1985. Archives of Internal Medicine, Sept. 8, 2003; vol 163: pp 1897-1904. CA: A Cancer Journal for Clinicians, July-August 2003; vol 53: pp 201-202. American Journal of Gastroenterology, August 2003; vol 98: pp 1790-1796.

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