Fiber is found in plants, where it functions as a skeleton to help plants maintain their shape and structure. Humans can't digest the fiber so when we eat plant-based foods, it passes through the small intestine into the colon where it helps maintain regularity and bowel health.
Some disorders like diverticulitis, constipation and irregularity may be connected with a lack of dietary fiber.
Insoluble and Soluble Fiber
Insoluble fiber doesn't dissolve in water so it helps move material through the colon by increasing the bulk of the stool. This can be very helpful to people who suffer from constipation or irregularity. Diets high in insoluble fiber may also decrease the risk of diabetes. Insoluble fiber is found in whole grains, nuts, wheat bran and vegetables.
Soluble fiber absorbs water, so it helps to soften stools as well as add bulk. Some types of soluble fiber also help to lower cholesterol levels. Soluble fibers are found in oats, citrus fruits, apples, barley, psyllium, flax seeds and legumes.
According to the Institute of Medicine:
The recommended intake for total fiber for adults 50 years and younger is set at 38 grams for men and 25 grams for women, while for men and women over 50 it is 30 and 21 grams per day, respectively, due to decreased food consumption.
High Fiber Foods
- one-half cup cooked navy beans - 9.5 g
- one-half cup baked beans, canned - 9.0 g
- one-half cup cooked lentils - 7.8 g
- one-half cup cooked black beans - 7.5 g
- one-half cup dates - 7.1 g
- one cup raisin bran cereal - 7.0 g
- one-half cup cooked kidney beans - 6.5 g
- one-half cup cooked lima beans - 6.7 g
- one-half cup canned tomato paste - 5.9 g
- one-half cup cooked garbanzo beans - 6.2 g
- one-half cup bean with ham soup - 5.6 g
- one-half cup frozen red raspberries - 5.5 g
- one medium bran muffin - 5.0 g
- one-half Asian pear - 5 g
- one-half cup cooked artichoke - 4.5 g
- one-half cup frozen peas, cooked - 4.4 g
- one cup oatmeal - 4.0 g
- one-half cup frozen mixed vegetables, cooked - 4.0 g
- one-half cup raw blackberries - 3.8 g
- one-half cup canned pumpkin - 3.5 g
- one-half cup cooked whole wheat spaghetti - 3.4 g
- 24 almonds - 3.3 g
- one apple with skin - 3.3 g
- one-half cup cooked barley - 3.0 g
- one medium orange - 3.0 g
- one cup broccoli - 2.4 g
- one red sweet pepper - 2.4 g
- one nectarine - 2.3 g
- 28 peanuts - 2.3 g
- one slice whole grain bread - 2.0 g
- 15 walnut halves - 2.0 g
Fiber Supplements are also available to augment your fiber intake. Eating more fiber doesn't mean you have to adopt a brand new diet. You can easily add extra fiber with just a few changes.
- Serve a easy to make fruit salad.
- Eat a fresh orange rather than drinking juice.
- Eat the skins of apples and pears.
- Don't peel your potatoes -- include the skins that also contain the most nutrition.
- Buy 100-percent whole grain breads instead of refined white bread.
- Add more vegetables to your stews or soup.
- Choose bran muffins instead of chocolate chip muffins.
- Snack on nuts, which are rich in fiber and healthy fats.
- Add fresh berries to your favorite yogurt.
- Substitute whole wheat flour for half of the white flour in your recipes.
- Eat oatmeal or oat cereals for breakfast and add some flax seeds for some healthy fats.
- Serve baked beans as a side dish.
Bloedon, Leanne T, Szapary, Philippe O. "Flaxseed and Cardiovascular Risk." Nutrition Reviews, Volume 62, Number 1, 1 January 2004, pp. 18-27(10).
J Chen1, J He1, R P Wildman, K Reynolds, R H Streiffer and P K Whelton. "A randomized controlled trial of dietary fiber intake on serum lipids." European Journal of Clinical Nutrition (2006) 60, 62 - 68.
Julie Robitaillea, Bénédicte Fontaine-Bissona, Patrick Couturea, André Tchernofa, Marie-Claude Vohl. "Effect of an Oat Bran-Rich Supplement on the Metabolic Profile of Overweight Premenopausal Women." Annals of Nutrition and Metabolism 2005;49:141-148.
Teresa T Fung, Frank B Hu, Mark A Pereira, Simin Liu, Meir J Stampfer, Graham A Colditz and Walter C Willett. "Whole-grain intake and the risk of type 2 diabetes: a prospective study in men." American Journal of Clinical Nutrition, Vol. 76, No. 3, 535-540, September 2002.