Q: What exactly is ‘fiber’ and why is it so good for you?
A: Fiber is an indigestible carbohydrate, or a string of sugar units held together by bonds that human digestive enzymes cannot break. There are two types: soluble and insoluble fiber.
Soluble fiber: barley, oats, oat bran, rye, fruits (especially apples and citrus), beans, vegetables, seeds
Insoluble fiber: Brown rice, fruits, beans, seeds, vegetables (cabbage, carrots, brussels sprouts), wheat bran, whole grains
While fiber does not provide energy, it has many other beneficial effects:
1. Lowers blood cholesterol: Soluble fiber reduces cholesterol and the risk of heart disease by several mechanisms. (Note: This is why General Mills is able to claim that eating whole grain oat Cheerios can help lower your cholesterol.)
2. Maintains bowel function: Insoluble fiber speeds up the transit of food through your system, while soluble fiber slows it down.
3. Assists blood glucose control: Soluble fiber slows the absorption of glucose from the intestine into the blood stream, thereby preventing a spike (and crash) in blood glucose after a meal. This can lower the risk of type 2 diabetes.
4. Promotes weight management: Fiber makes you feel full and lessens hunger
5. May defend against colon and rectal cancer: Scientific studies are mixed, but insoluble fiber speeds up the removal of cancer-causing agents from the colon, while resident bacteria in the colon ferment soluble fiber, producing a beneficial compound that may help colon cells resist injury.
Recommended Intake: Since most fiber-rich foods supply a mixture of soluble and insoluble fiber, recommendations are given without regard to type. The American Dietetic Association suggests 20 – 35 grams of fiber daily, which is about twice the average intake. That said, don’t overload on fiber and make sure to increase fluid consumption as you gradually increase fiber intake.
Fruits, vegetables, whole grains and beans are among the best sources of fiber! Also, remember that fiber supplements are not necessarily substitutes for whole, fiber-rich foods.
Check the nutrition facts on the back of products to find out how much fiber is in one serving! Here are some examples:
½ cup whole grain barley – 3g fiber
½ cup instant oatmeal – 2g fiber
1 slice whole wheat bread – 3g fiber
1 slice white bread – 1g fiber
½ cup cooked brown rice – 2g fiber
½ cup cooked white rice – less than 1g fiber
¾ cup (2 oz) whole wheat penne pasta, dry – 6g fiber
¾ cup (2 oz) regular penne pasta, dry – 2g fiber
1 medium apple (with skin) – 3g fiber
1 medium pear (with skin) – 5g fiber
½ cup blackberries – 4g fiber
½ cup strawberries – 2g fiber
1 medium orange – 4g fiber
½ cup orange juice – less than 1g fiber
½ cup lentils – 8g fiber
½ cup chickpeas (garbanzo beans) – 5g fiber
½ cup black beans – 7.5g fiber
½ cup cooked broccoli – 2.5g fiber
1 medium artichoke – 10g fiber
1 medium baked potato (with skin) – 4.5g fiber