The treatment of several gastrointestinal conditions is based upon the establishment of increased fiber in your diet. These include irritable bowel syndrome, diverticulosis and internal/external hemorrhoids. Some research data also indicates that increasing the amount of fiber in your diet may decrease the incidence of colon cancer. In addition, the American Cancer Society and the U.S. Government both recommend a diet with between 35-39 grams of fiber per day. Such a diet may also improve your cholesterol and help prevent heart disease. 

The following information should help guide you through the process of increasing the amount of fiber in your diet.

What is fiber? 

Fiber is found in plants and is generally not digested or absorbed by the body. Many different types of fibers exist and they are grouped into two broad categories. Each has a role in promoting good health. The two general types are water soluble fibers and insoluble fibers. 

Water soluble fibers can aid in the treatment of high cholesterol levels, diabetes and obesity. By forming a gel, water soluble fibers stay in your stomach longer and help slow food absorption. Water-soluble fibers are found in oats, bran, dried beans, potatoes, seeds, apples, oranges, and grapefruit. 

Insoluble fibers hold water to produce softer, bulkier stools. These fibers are found in wheat and corn brans, nuts and many fruits and vegetables. By promoting better regularity, a diet high in insoluble fibers helps relieve constipation and control diverticular disease. People with diverticular disease are encouraged to eat a high fiber diet with a general avoidance of nuts, seeds, hulls and some skins since these can cause acute inflammation of the diverticula resulting in diverticulitis. 

Insoluble fibers may also help in preventing colon cancer. 

Tips for increasing fiber in your diet 

  • Substitute whole wheat flour for half or all of the flour in home baked goods.
  • When buying breads, crackers and breakfast cereals, make sure the first ingredient listed is whole wheat flour or another whole grain.
  • Use brown rice, whole grain barley, bulgur (cracked wheat), buckwheat, groats (kasha) and millet in soups and salads, or as cereals and side dishes.
  • Try a variety of whole wheat pastas in place of regular pasta.
  • Sprinkle bran in spaghetti sauce, sloppy joes, ground meat mixtures and casseroles, pancakes, and other quick breads, and in cooked cereals and fruit crisp toppings.
  • Eat skins and edible seeds of raw fruits and vegetables.
  • For high fiber snacks, eat fresh fruit and vegetables, whole grain crackers or popcorn.
  • For lunches, pick crunchy vegetables stuffed in whole wheat pita bread, salads and hearty vegetable and bean soups.
  • For dessert, bake berry pies, apples stuffed with prunes, dates, and raisins; fruit compotes; whole wheat fruit breads; brown rice or whole wheat bread puddings; and whole wheat cakes and cookies.
  • Try Middle Eastern, Oriental and Mexican dishes that make liberal use of vegetables, whole grains and dried beans.
  • Use whole grain or bran cereals for crunchy toppings on ice cream, yogurt, salads or casseroles. Nuts, toasted soybeans, sunflower kernels, and wheat germ also can add interesting flavors and increase the fiber content of you meal.
  • Many vegetarian and high fiber cookbooks contain excellent high fiber recipes.

Note that many fiber values listed on labels, cookbooks and other reference materials use crude fiber values which are now outdated. Therefore, it is recommended that you use the dietary fiber values listed on the following pages when planning your meal menus. 

Fiber and Weight Loss 

High fiber foods offer a great plus for dieters! Many high fiber foods are naturally bulkier and more filling than refined foods, you tend to eat less calories on high fiber diets. 

Avoiding Problems with Increasing Fiber 

When increasing your dietary fiber, remember to include a variety of soluble and insoluble fiber food sources including whole grain breads and cereal, fruits and vegetables. While increasing your dietary fiber you should also drink at least 8 cups of fluid every day. Remember that water, milk, juice and decaffeinated sodas, teas and coffee are also sources of fluid. 

People who typically eat low fiber diets may experience increased flatulence (gas from below), bloating and occasionally diarrhea when they begin to eat large amounts of fiber all at once. To prevent these discomforts, the amount of fiber in your diet should be gradually increased. 

The amount of fiber in your present diet can be estimated with the charts below. Estimate your present fiber intake and increase you weekly fiber intake by 2-4 grams. Thus, if in Week 1, you have a base fiber content of 20 grams/day you would try to increase the amount of fiber to 22-24 grams/day for the first week. Then, in Week 2, the total fiber would be 24-28 grams/day. You can determine the amount of fiber added per day that works best for you. This should be based upon the amount of gas and bloating you experience with the dietary changes. If there is too much gas and bloating, then decrease the amount of fiber. 

Remember, the overall goal is to increase the fiber in your diet gradually and maintain this over a lifetime. 

Fiber Supplements 

Commercial fiber supplements are available, ranging from bran tablets to purified cellulose (an insoluble fiber). Many laxatives sold as stool softeners are actually fiber supplements. Since different types of fibers work in different ways, no one fiber supplement provides all of fiber’s potential benefits. Persons unable to change their diets might benefit from fiber supplements as suggested. 

It is more beneficial, however, to increase the amount of dietary fiber by eating a variety of high fiber foods sources. 

Dietary Fiber Values

Breads and Pastas

Food Serving Fiber
Cooked whole wheat spaghetti 1 cup 4 grams
Whole wheat bread 2 slices 3 grams
Bran muffin one (1) 3 grams
Crisp bread, wheat or rye 2 crackers 2 grams
Cracked wheat bread 2 slices 2 grams
Mixed grain bread 2 slices 2 grams
Pumpernickel bread 2 slices 2 grams
Brown rice (cooked) 1 cup 2 grams
Spaghetti, macaroni, cooked 1 cup 1 gram

Flours and Grains

Food Serving Fiber
Rye Flour 1 cup 14 grams
Wheat Flour, whole meal 1 cup 11 grams
Wheat Flour, brown 1 cup 7 grams
Bran, corn 2 tbs. 7 grams
Bran, wheat 2 tbs. 5 grams
Bran, oat 2 tbs. 3 grams
Wheat flour, white 1 cup 3 grams
Rolled oats 1/3 cup 2 grams

Cereals

Food Serving Fiber
Fiber One® 1/3 cup 12 grams
All Bran® 1/3 cup 9 grams
100% Bran® 1⁄2 cup 8 grams
Bran Buds® 1/3 cup 8 grams
Corn Bran® 2/3 cup 5 grams
Bran Chex® 2/3 cup 5 grams
Shredded Wheat & Bran® 2/3 cup 4 grams
Fruit & Fiber® 1/3 cup 4 grams
Cracklin' Bran® 1/3 cup 4 grams
40% Bran® ¾ cup 4 grams
Most® 2/3 cup 4 grams
Raisin Bran® 3/4 cup 4 grams
Wheat germ 1/4 cup 3 grams
Honey Bran® 7/8 cup 3 grams
Shredded Wheat® 2/3 cup 3 grams
Wheat and Raisin Chex® 3/4 cup 3 grams
Frosted Mini Wheats® 4 biscuits 2 grams
Wheat Chex® 2/3 cup 2 grams
Total® 1 cup 2 grams
Wheaties® 1 cup 2 grams
Nutri-Grain® 3/4 cup 2 grams
Graham Crackers 3/4 cup 2 grams
Oatmeal, regular, quick, instant 3/4 cup 2 grams
Grape Nuts® 1/4 cup 2 grams
Cheerios® 1-1/4 cups 2 grams
Heartland Natural Cereal® 1/4 cup 1 gram
Crispy Wheats'n Raisins® 3/4 cup 1 gram
100% Natural Cereal®, plain 1/4 cup 1 gram
Tasteeos® 1-1/4 cup 1 gram

Cooked Vegetables

Food Serving Fiber
Peas 1/2 cup 4 grams
Corn, canned 1/2 cup 3 grams
Parsnips 1 medium 3 grams
Potato w/skin 1 medium 3 grams
Sweet potato 1 medium 3 grams
Broccoli 1/2 cup 2 grams
Brussels Sprouts 1/2 cup 2 grams
Carrots 1/2 cup 2 grams
Zucchini 1/2 cup 2 grams
Eggplant 1/2 cup 2 grams
Spinach 1/2 cup 2 grams
Green Beans 1/2 cup 2 grams
Turnips 1/2 cup 2 grams
Sauerkraut 1/2 cup 4 grams
Kale leaves 1/2 cup 1 gram
Potato w/o skin 1 medium 1 gram
Squash, summer 1/2 cup 1 gram
Asparagus 1/2 cup 1 gram
Cauliflower 1/2 cup 1 gram
Cabbage, red or white 1/2 cup 1 gram

Raw Vegetables

Food Serving Fiber
Avocado 1/2 medium 2 grams
Bean sprouts 1/2 cup 2 grams
Tomatoes 1 medium 2 grams
Spinach 1/2 cup 1 gram
Lettuce 1 cup 1 gram
Mushroom 1/2 cup 1 gram
Onions 1/2 cup 1 gram
Celery 1/2 cup 1 gram

Legumes

Food Serving Fiber
Baked beans w/ tomato sauce 1/2 cup 9 grams
Kidney Beans, cooked 1/2 cup 7 grams
Navy Beans 1/2 cup 6 grams
Dried peas, cooked 1/2 cup 5 grams
Lima Beans, canned & cooked 1⁄2 cup 5 grams
Lentils, cooked 1/2 cup 4 grams

Snacks

Food Serving Fiber
Almonds 1/4 cup 5 grams
Peanuts 1/4 cup 3 grams
Popcorn, popped 3 cups 2 grams
Walnut pieces 1/4 cup 2 grams
Olives 10 2 grams

Fruits

Food Serving Fiber
Blackberries 1/2 cup 5 grams
Pears 1 large 5 grams
Apple 1 medium 4 grams
Prunes 4 4 grams
Raspberries 1/2 cup 3 grams
Raisins 1/4 cup 3 grams
Honeydew Melon 1/4 medium 3 grams
Strawberries 1 cup 3 grams
Orange 1 medium 3 grams
Nectarine 1 medium 3 grams
Banana 1 medium 2 grams
Blueberries 1/2 cup 2 grams
Peach w/ skin 1 medium 2 grams
Dates 3 2 grams
Apricots, dried 5 halves 1 gram
Cherries, sweet 10 1 gram
Peach w/o skin 1 1 grams
Pineapple 1/2 cup 1 gram
Cantaloupe 1/4 1 gram

Credits for this dietary information go to Maureen Murtaugh, PhD.