Many people seem to believe that the only benefit of taking in enough dietary fiber is staying “regular.” While this is certainly one benefit, fiber has many other qualities that make it one of the most important nutrients to include in a daily diet. In addition to promoting regular bowel movements, eating a variety of fiber-rich foods can help to:
• Lower LDL (“bad”) cholesterol
• Regulate blood sugar levels
• Support digestive health
• Promote a sense of “fullness” that can aid in weight loss
• Help lower the risk of developing Type 2 diabetes and heart disease
What is Fiber?
Fiber comes from plant foods—specifically from the structural part of plants that cannot be fully digested by the human gut—and comes in two types: soluble and insoluble. Many plant foods contain a mixture of both types, but each type helps the body in different ways, so it’s best to eat a variety of fiber-rich foods.
Soluble fiber absorbs water in the digestive tract, forming a gel-like substance in the intestines. This substance binds to cholesterol and carries it out of the body in the form of stool, preventing its absorption into the blood. Eating just 5-10 grams of soluble fiber per day can help lower a person’s LDL cholesterol levels.
By absorbing water, soluble fiber also helps to create softer stools that pass more easily through the digestive tract, preventing constipation. Soluble fiber also helps you feel full for longer periods of time.
Since fiber is not absorbed well by the body, it does not contribute to spikes in blood sugar levels. It can also help to slow the absorption of sugar from other foods, making it an important component in regulating blood sugar levels.
Food Sources of Soluble Fiber
Food Serving Size Soluble Fiber (grams)
Oatmeal (cooked) 1 cup 4
Mango 1 small 3.4
Black beans ½ cup 2.4
Oat bran cereal (cooked) ¾ cup 2.2
Brussels sprouts ½ cup 2
Apricots (fresh) 4 1.8
Orange 1 small 1.8
Flaxseed (ground) 1 tablespoon 1.1
Insoluble fiber adds bulk to stools, helping to move waste through the body and prevent constipation. It also promotes weight loss by helping you feel full for longer periods of time, helping you avoid over-eating.
Food Sources of Insoluble Fiber
Food Serving Size Insoluble Fiber (grams)
Wheat bran ½ cup 11.3
Black beans ½ cup 3.7
Pear (fresh, with skin) 1 large 3.6
Green peas ½ cup 3
Raspberries 1 cup 2.4
Flaxseed (ground) 1 tablespoon 2.2
Barley (cooked) ½ cup 2.2
Sweet potato (without skin) ½ cup 2.2
Whole wheat pasta (cooked) ½ cup 2.1
Apple (fresh, with skin) 1 small 1.8
Banana 1 small 1.6
How Much Fiber Do We Need?
In general, you should try to get about 14 grams of fiber for every 1,000 calories you eat. For more specific guidelines by age and gender, however, see the figures below:
1-3 years: About 19 grams/day
4-50 years: About 25 grams/day
Older than 50 years: About 21 grams/day
1-3 years: About 19 grams/day
4-8 years: About 25 grams/day
9-13 years: About 31 grams/day
14-50 years: About 38 grams/day
Older than 50 years: About 30 grams/day
Simple Ways to Increase Your Fiber Intake
With just a little planning and by making some healthy choices about the foods you eat, you can easily add additional fiber to your diet each day:
• Choose whole grains or products with whole grains as the first ingredient (such as oats, barley, quinoa, wild rice).
• Choose lean protein sources that also provide fiber (such as beans, nuts, chickpeas).
• Eat whole fruits and vegetables instead of drinking juices.
• Choose vegetables that are high in soluble fiber (such as Brussels sprouts, broccoli, green beans, carrots).
• Add fiber “extras” (such as raisins, nuts, flaxseed, chia seeds and dried beans) to common dishes.
What about Fiber Supplements?
Research has shown that low fiber intake is associated with certain health risks. Nevertheless, only about 5 percent of the adult population in the United States gets the recommended amount of dietary fiber. To help make up for that shortfall, fiber supplements may be useful. However, while supplements are a convenient, concentrated source of fiber, be careful not to rely on them too much—most supplements do not provide the same health benefits as those derived from fiber that comes from food.
If you do decide to take a fiber supplement, be sure to select one that contains soluble fiber. Psyllium is a form of fiber that is rich in soluble fiber and may promote bowel regularity, as well as lower LDL cholesterol and aid in blood sugar control.
Taking excessive fiber supplements can cause bloating and gastrointestinal discomfort, so in general you should get no more than 10 grams of fiber per day from supplements. Use supplements only if you’re unable to get the recommended amount of fiber through the whole foods you consume.