Increasing dietary fiber can often help improve mild constipation, but its effects can be less reliable for more severe cases. In some individuals with slow colonic transit, or colonic inertia, increasing fiber may actually worsen symptoms.
Dietary fiber is an indigestible carbohydrate that is classified into two types: soluble and insoluble fiber. Each type has unique properties and health benefits. Soluble fiber dissolves in water, forming a gel-like substance, while insoluble fiber does not dissolve; instead, it absorbs liquid and adds bulk to stool.
Both types of fiber are essential for a healthy diet and contribute positively to the digestive system. However, fiber can have mixed results for individuals with intestinal disorders. Certain high-fiber foods, such as bran, may increase discomfort.
If you experience bloating or pain after consuming fiber, it is likely due to insoluble fiber, which is mainly found in cereals and whole grains. Soluble fiber, found primarily in vegetables and fruits, tends to cause fewer issues. However, this can vary from person to person, so it may require some trial and error to determine what works best for you.
Many Americans consume only a small portion of the recommended daily intake of 20–35 grams of fiber. For some, this is due to an inability to tolerate fiber. Consulting a healthcare provider or registered dietitian can offer personalized advice on dietary fiber consumption.
When introducing fiber to your diet, it’s best to do so gradually over several weeks. If you experience gas, bloating, or abdominal distention, consider reducing your fiber intake and cutting back on foods that produce gas.
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 |
