The Dish on Fiber
Fiber is required to be included on all packaged food labels because it is a nutrient that most North Americans consume too little of and need to increase. Fiber is found in the outer layer of grains (mostly in the bran) but this part is removed when grains are processed. Fruits, vegetables, and whole gains are good sources of dietary fiber. Because the body is unable to break down the bonds that hold fiber molecules together, we do not use fiber as a source of energy (aka calories). The healthy bacteria in our large intestine, however, can metabolize fiber and as they do, these bacteria produce short-chain fatty acids which improve the health of our intestinal lining. (The bacteria particularly like soluble fiber.)
Getting enough fiber in your diet is beneficial for maintaining regularity (not becoming constipated), lowering blood cholesterol, managing your weight (fiber helps you feel full without contributing any significant amount of calories), and lowers your risk for diverticulitis, obesity, diabetes, cardiovascular disease and some cancers.
How much fiber do you need?
The Daily Reference Intakes (DRIs) for Fiber are approximately 25g/day for females (ages 19-30) and 38g/day for males of the same age group. As a reference, a small bowl of black bean soup contains about 14g of dietary fiber. A small apple contains about 4g of dietary fiber, a slice of whole wheat bread contains about 2 g, and white bread about 1g.
*Make sure that if you increase your fiber intake you also drink more water! Eating too much fiber without enough water will not allow insoluble fiber to work properly with your body and you will probably end up with constipation.
Soluble vs. Insoluble Fiber
What’s the difference and why do I need both?
- Found in fruits, beans, oats and barely
- Helps “bulk up” meal, stays in stomach longer, helping you to feel full
- Binds to and traps cholesterol molecules and moves them along in to the colon and out as waste (aka helps lower blood cholesterol)
- Found in vegetables (especially starches), bran from whole grains, and whole grain breads and cereals
- Decreases intestinal transit time
- Decreases constipation
- Lowers risk for diverticular disease
- May lower risk for colon cancer