Fiber facts: Roughing-up your sports diet

As a nutritionist, I commonly hear my clients proclaim, "I'm trying to eat more salads for roughage ..."

They know that fiber is health-protective it promotes regular bowel movements, reduces the risk of heart disease, improves blood sugar control, reduces the risk of adult-onset diabetes, and enhances weight reduction. (Fiber-rich foods take longer to chew and help you feel full.) But little do they know one of the best sources of roughage is not lettuce but bran cereal.

Granted, eating lettuce can contribute towards a positive fiber intake, but youd need to eat 6 pounds of the stuff to get the recommended 30 grams of fiber! Other foods offer more of a fiber boost.

Here's some information on how to roughen up your diet.

Types of fiber
You should try to eat a variety of fiber-rich foods on a daily basis because different foods offer different types of fiber with different health benefits. The two main types of fiber are:

Insoluble fiber. This type of fiber gives plants their structure. It does not dissolve in water. Common sources are wheat bran, vegetables and whole grains. Insoluble fiber absorbs water, increases fecal bulk, and makes the bowels easier to pass.

Soluble fiber. This type of fiber forms a gel in water. It is in oatmeal, barley and kidney beans (as well as in pectin and guar gums, two fibers often added to foods and listed among the ingredients). Soluble fiber lowers blood cholesterol, particularly in people with elevated cholesterol.

Soluble fiber can also help stabilize blood glucose levels, making fiber-rich snacks a wise pre-exercise choice (assuming they settle comfortably). Some sustaining pre-exercise snacks include oatmeal (and oatmeal breads, cookies, muffins) as well as beans and legumes, such as lentil soup, refried beans, hummus, chili and chick peas.

Fiber for constipation
Constipation is a concern for many active people. Although the "normal" pattern for bowel movements varies from person to person, infrequent hard, dry stools are a sign of constipation.

Being "too busy" to go to the bathroom aggravates the problem; exercise, particularly running, alleviates it.

To help "eliminate" constipation problems, gradually increase your intake of high-fiber plant foods. Bran cereals are among the foods highest in fiber. A serving of bran cereal such as Fiber-One mixed with granola or Grape-Nuts and topped with berries is an easy way to rapidly boost your fiber intake. Eating some fruit and/or vegetables at all three meals can also do the job.

Fiber increases fecal weight and the number of trips to the bathroom, but it usually does not increase transit time (normally 2 to 4 days). Transit time varies according to stress, exercise and diet.

Your best bet as an active person is to find the right combination of fiber-rich foods that promotes regular bowel movements for your body. (Some athletes have to restrict their fiber intake.)

Note: In addition to eating a fiber-rich diet, be sure to drink plenty of fluids throughout the day. Drinking warm liquids in the morning is particularly helpful to stimulate bowel activity because your body naturally wants to defecate about a half-hour after consuming a warm beverage. Be sure to schedule time to relax and honor this urge. If necessary, get up earlier so you won't be commuting to work when you should be sitting on the toilet.

Where to find fiber
Fiber is lost through food processing, such as milling whole wheat into white flour; peeling skins from fruits (apples, pears) and vegetables (potatoes, cucumbers); pureeing, straining and juicing.

You'll get more fiber by choosing unrefined foods. As little as 5 to 10 grams of fiber can change bowel behavior. The recommended daily intake is 20 to 35 grams.

Here's a list of fiber-rich foods to guide your daily food choices.

Bran cereals are the easiest way to boost fiber intake:
Fiber-One, 1/2 cup, 14 grams per ounce of cereal
All-Bran with Extra Fiber, 1/2 cup, 13 g/oz
All-Bran, 1/2 cup, 10 g/oz
Complete Bran Flakes, 3/4 cup, 5 g/oz
Grape-Nuts, 1/4 cup, 3 g/oz
Oatmeal, 1 packet instant, 3 g/oz
Frosted Mini-Wheats, 1/2 cup, 3 g/oz
Cheerios, 1 cup, 3 g/oz

Breads and crackers made from whole-grain flours (whole wheat, rye, oats, corn) are high in fiber, as are bran breads and muffins.
Bran muffin, Dunkin Donuts, 5 grams of fiber
Triscuits, 8 reduced fat, 4g
Rye-crisp, two, 3g
Branola Bread, 1 slice, 3g
Honey wheat berry, 1 slice, 3g
Pumpernickel bread, 1 slice, 2g
Whole wheat bread, 1 slice, 2g
White, 1 slice, 0.5g

Fresh fruits with edible skins are highest in fiber.
Pear, medium, 4 grams of fiber
Apple, medium, 4g
Orange, medium, 3g
Banana, medium, 3g

Berries with seeds are a good source of fiber (grams/100 cals):
Raspberries (1.75 cup), 14 grams
Blackberries (1.5 cup), 10g
Strawberries (2 cups), 8g
Blueberries (1.2 cup), 55

Dried fruits are another good source of fiber (grams/100 cals):
Figs, two, 4 grams of fiber
Apricots, 12 halves, 4g
Apple, six rings, 4g
Prunes, five, 3g
Dates, four, 3g
Raisins, seedless (1/4 cup), 1g

Vegetables with edible skins (potato, cucumber) and seeds (tomato, zucchini) are highest in fiber.
Broccoli, 1 cup; 50 cals, 5 grams
Potato. 1 lg w/skin; 200 cals, 5g
Green beans, 1 cup; 50 cals, 4g
Peas, 1/2 cup; 60 cals), 4g
Carrots, 1 raw large; 50 cals, 3g
Corn, 1/2 cup; 75 cals, 2g
Pepper, 1 large; 50 cals), 2g
Lettuce, 2 cups, 2g

Beans and legumes, such as lentils and split peas, are excellent sources of fiber as well as protein. Protein-rich animal foods (meat, chicken, fish, eggs and dairy products) lack fiber.
Refried beans, 1/2 cup, 7 grams
Baked beans, 1/2 cup, 6g
Hummus, 1/2 cup, 6g
Kidney beans, 1/2 cup, 6g

Nuts and seeds are good for fiber-rich snacks, as are baked goods with dried fruits and nuts:
Almonds, 24; 165 cals, 3 grams
Sunflower seeds, 1 oz; 160 cals, 3g
Peanut butter, 2 Tbsp; 200 cals, 2g
Sesame seeds, 1 T; 50 cals, 1g

Low-fiber foods include foods that are not from plants: meat, fish, chicken, eggs, milk, cheese; sugar, sweets; butter, oil.

Copyright May 2003: Nancy Clark, MS, RD

Nancy Clark, MS, RD is nutrition counselor at SportsMedicine Associates in the Boston area (617-739-2003) and author of "Nancy Clark's Sports Nutrition Guidebook" ($23) and her "Food Guide for Marathoners: Tips for Everyday Champions" ($20). Both are available via or by sending a check to 830 Boylston St. #205, Brookline MA 02467.

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