What is fiber?
Fiber is a type of carbohydrate. It is the portion of plant food that cannot be digested by the body.
There are two types of fiber found in all plant foods:
- Soluble fiber (or viscous fiber) dissolves in water and forms a gel.
- Insoluble fiber does not dissolve in water.
How does our body use fiber?
Soluble Fiber
Soluble fiber binds to some bile salts and removes them from the body — lowering blood cholesterol levels and improving heart health.1 It also slows and reduces the absorption of other carbohydrates that may spike blood sugar levels — reducing the risk of developing diabetes.
Insoluble Fiber
Insoluble fiber passes through our digestive system mostly unchanged. It provides bulk to keep the digestive system moving — improving the frequency and density of bowel movements. As a result, insoluble fiber decreases the risk of several gastrointestinal disorders, including chronic constipation, hemorrhoids, irritable bowel syndrome, and colon cancer.
Additional Health Benefits
A high intake of dietary fiber has been associated with a reduced risk of cardiovascular disease, infectious diseases, and respiratory diseases.2 Increasing your dietary fiber intake can also aid with weight loss. One study found that participants who were told to consume 30 grams of fiber per day were able to lose an average of 4.6 pounds and maintain the weight loss over the next 12 months.3
How much fiber do I need?
The average American consumes roughly half of the dietary fiber recommended by health organizations.4 According to the latest recommendations from the USDA, you should consume 14 grams of fiber per 1,000 calories consumed.5 For a person consuming 2,000 calories per day, this is equal to 28 grams of fiber.
[Grams of fiber] = [caloric intake] x 0.014
What are good sources of fiber?
| Food | Qty | Fiber (g) | Soluble (g) | Insoluble (g) |
|---|---|---|---|---|
| Lentils | 1 cup | 15.6 | 6.7 | 8.9 |
| Oatmeal | 1 cup | 8.0 | 4.2 | 3.8 |
| Pearled Barley | 1 cup | 5.9 | 1.7 | 4.2 |
| Navel Orange | 1 orange | 4.4 | 0.8 | 3.6 |
| Carrots | 1 cup | 4.0 | 1.1 | 2.9 |
| Almonds | 1/3 cup | 4.0 | 0.6 | 3.4 |
| Green Beans | 1 cup | 3.8 | 1.5 | 2.3 |
| Brussels Sprouts | 1 cup | 3.3 | 1.7 | 1.6 |
Additional Resources
Sources
- Gunness, P., & Gidley, M. J. (2010). Mechanisms Underlying the Cholesterol-lowering Properties of Soluble Dietary Fibre Polysaccharides. Food & Function, 1(2), 149.
- Park, Y., Subar, A. F., Hollenbeck, A., & Schatzkin, A. (2011). Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study. Archives of Internal Medicine, 171(12).
- Ma, Y., Olendzki, B. C., Wang, J., Persuitte, G. M., Li, W., Fang, H., … Pagoto, S. L. (2015). Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome. Annals of Internal Medicine, 162(4), 248.
- What We Eat in America: Nutrient intakes from food by gender and age. National Health and Nutrition Examination Survey (NHANES) 2009-10. US Department of Agriculture; Agricultural Research Service.
- 2020-2025 Dietary Guidelines for Americans. U.S. Department of Health and Human Services and U.S. Department of Agriculture.