Dietary fiber is often effective in improving mild constipation. However, it has less consistent results with more severe constipation. It can possibly worsen symptoms in people with slow colonic transit (colonic inertia).
Dietary fiber is defined as indigestible carbohydrate. It’s classified into soluble (in water) and insoluble fiber – each with specific properties and possible health benefits. Soluble fiber dissolves in water; it forms a gel when water is added to it. Insoluble fiber absorbs liquid and in the intestine it adds bulk to stool. Both types of fiber are important in the diet and have digestive system benefits.
But fiber can be a double-edged sword for persons with intestinal disorders. Certain high fiber foods, such as bran, may increase discomfort.
If you find that fiber is seems to be a problem that causes you to feel bloating or pain, it is usually insoluble fiber (mainly found in cereals or whole grains) that is the problem. Soluble fiber, mainly found in vegetables and fruits, is less likely to be a problem. But the reaction is the opposite in some people, so trial and error may be the best option.
A physician or registered dietitian can provide individual advice on dietary fiber consumption.
When adding fiber to the diet, it is best to do so slowly over a period of weeks. If gas, bloating or distention occur, try reducing the dose of fiber and reducing consumption of gas-producing foods.
Examples of gas-producing foods to watch out for include:
- beans
- cabbage
- legumes (e.g., peas, peanuts, soybeans)
- apples
- grapes
- raisins
Tips on Adding Dietary Fiber
Experiment with fresh foods and don’t be afraid to try new foods and recipes. Here are a few practical tips for adding fiber to your diet.
- Vegetables
- Cook in microwave to save time and nutrients
- Cook only until tender-crisp to retain taste and nutrients
- Beans
- Presoaking reduces the gas-producing potential of beans if you discard the soaking water and cook using fresh water
- Fruit
- Snack on fruit anytime, anywhere
- Leave peelings on fruit whenever possible
- Use fresh and dried fruit in muffins, pancakes, quick breads, and on top of frozen yogurt
- Grains
- Choose whole-grain varieties of breads, muffins, bagels, and English muffins
- Mix barely cooked vegetables with pasta for a quick pasta salad
How much Fiber?
The National Academy of Sciences’ Institute of Medicine, gives the following daily recommendations for adults: 38 grams for men and 25 grams for women 50 and younger; 30 grams for men and 21 grams for women 51 and older.
Sampling of dietary fiber content of foods (appx. g/serving)
Source: USDA National Nutrient Database for Standard Reference, Release 17
Vegetables
| Food | Serving Size | Grams of Fiber |
|---|---|---|
| Beans (navy), cooked | 1/2 cup | 9.5 |
| Beans (pinto, black), cooked | 1/2 cup | 7.7 |
| Chickpeas (garbanzo beans), cooked | 1/2 cup | 6.2 |
| Lentils, cooked | 1/2 cup | 7.8 |
| Potato (with skin), baked | 1 potato | 4.4 |
| Peas (frozen), cooked | 1/2 cup | 4.4 |
| Mixed Veggies (frozen), cooked | 1/2 cup | 4.0 |
| Soybeans, cooked | 1/2 cup | 3.8 |
| Broccoli, cooked | 1/2 cup | 2.5 |
| Carrots, cooked | 1/2 cup | 2.3 |
| Carrots, raw | 1 carrot | 2.0 |
| Green beans, cooked | 1/2 cup | 2.0 |
| Sweet corn (on the cob), cooked | 1 ear | 1.8 |
| Vegetable soup (Progresso™) | 1 cup | 1.4 |
| Lettuce (romaine), raw | 1 cup | 1.2 |
| Lettuce (green leaf), raw | 1 cup | 0.7 |
| Celery, raw | 1 stalk | 0.6 |
Fruits
| Food | Serving Size | Grams of Fiber |
|---|---|---|
| Raspberries (sweetened), frozen | 1/2 cup | 5.5 |
| Pears, raw | 1 pear | 5.1 |
| Raspberries, raw | 1/2 cup | 4.0 |
| Blackberries, raw | 1/2 cup | 3.8 |
| Apples (with skin), raw | 1 apple | 3.3 |
| Oranges, raw | 1 orange | 3.1 |
| Bananas, raw | 1 banana | 3.1 |
| Raisins (1 miniature box), seedless | 14 g | 0.6 |
| Pears, canned in syrup | 1/2 cup | 2.2 |
| Grapefruit (pink and red), raw | 1/2 grapefruit | 2.0 |
| Grapefruit (white), raw | 1/2 grapefruit | 1.3 |
| Orange juice (unsweetened), frozen concentrate | 6-fl-oz can | 1.7 |
| Applesauce (sweetened), canned | 1/2 cup | 1.5 |
Grains
| Food | Serving Size | Grams of Fiber |
|---|---|---|
| Barley (pearled), cooked | 1/2 cup | 3.0 |
| Oat bran, cooked | 1/2 cup | 2.8 |
| Rice (brown), cooked | 1/2 cup | 1.7 |
| Rice (white, long-grained), instant | 1/2 cup | 0.5 |
| Bagels | 4″ bagel | 2.0 |
| Bread, whole-wheat, rye | 1 slice | 1.9 |
| Spaghetti, cooked | 1/2 cup | 1.7 |
| Bread, raisin | 1 slice | 1.1 |
Cereal (includes brand names)
| Food | Serving Size | Grams of Fiber |
|---|---|---|
| Kellogg’s All-Bran | 1/2 cup | 8.8 |
| Kellogg’s Raisin Bran | 1/2 cup | 3.6 |
| Wheatena, cooked with water | 1/2 cup | 3.3 |
| Shredded wheat, plain no sugar | 2 biscuits | 5.5 |
| Quaker Oats, honey and raisins | 1/2 cup | 4.2 |
| Quaker Low fat Natural Granola with Raisins | 1/2 cup | 2.8 |
| Quaker Instant Oatmeal, apples and cinnamon, with boiling water | 1 packet | 2.7 |
| Kellogg’s Frosted Mini-Wheats | 1/2 cup | 2.5 |
| General Mills Raisin Nut Bran, Total Raisin Bran | 1/2 cup | 2.5 |
| General Mills Cheerios | 1/2 cup | 1.8 |
| General Mills Wheaties | 1/2 cup | 1.5 |
| General Mills Lucky Charms | 1/2 cup | 0.7 |
| Kellogg’s Frosted Flakes | 1/2 cup | 0.7 |
| Kellogg’s Apple Jacks | 1/2 cup | 0.5 |
| General Mills Golden Grahams | 1/2 cup | 0.6 |
| General Mills Trix | 1/2 cup | 0.4 |
| Kellogg’s Fruit Loops, Cocoa Krispies | 1/2 cup | 0.4 |
| Kellogg’s Special K, Corn Flakes | 1/2 cup | 0.3 |
| Quaker Cap’n Crunch | 1/2 cup | 0.3 |
| General Mills Rice Chex | 1/2 cup | 0.1 |
Other
| Food | Serving Size | Grams of Fiber |
|---|---|---|
| Soup, bean with ham (canned) | 1 cup | 11.2 |
| Pasta with meatballs, tomato sauce, canned | 1 cup | 6.8 |
| Soup, Progresso Classic Lentil™, canned | 1 cup | 5.6 |
| Baked pork and beans (canned) | 1/2 cup | 5.0 |
| French fried potatoes, fast food | 1 medium | 4.7 |
| Mixed nuts, dry roasted with peanuts and salt | 1 oz | 2.6 |
| Peanuts, dry roated with salt | appx 28 (1 oz) | 2.3 |
| Chocolate Milk | 1 cup | 2.0 |
| Tortilla chip snacks | 1 oz | 1.8 |
| Cheese pizza, regular crust, frozen | 1 serving | 1.4 |
| Potato chip snacks, plain, salted | 1 oz | 1.3 |
