Spotlight on Dietary Fiber
Why we need it and how to get it
We all know that eating more high-fiber foods
is a good thing. What we tend to be a little less sure of is how to incorporate it into our diet. Fortunately, it's not that hard because quite a few high-fiber – and tasty – foods and snacks are available. All it takes is a little information and some pairing up of what you enjoy with the appropriate sources of fiber. But before tracking those foods down, or even describing dietary fiber, let's look at the reasons why it matters.
The benefits of more fiber in your diet
Dietary fiber, which some people refer to as roughage or bulk, is probably best known for its ability to prevent or relieve constipation and support overall bowel health. That's a worthy benefit in and of itself, but there's more.
For example: One form of fiber helps lower total blood cholesterol levels by lowering low-density lipoprotein or "bad" cholesterol levels. Studies also show that fiber plays a role in other heart-health benefits, such as reducing blood pressure and inflammation.
Fiber can also help control blood sugar levels in people with diabetes by slowing the absorption rate of the blood sugar. A healthy diet that's high in fiber may also reduce the risk of developing Type 2 diabetes.
And there's still more: Because of their density and consistency, foods that are high in dietary fiber usually take longer to chew, giving your body time to send a signal to your brain that you are no longer hungry. As a result, you're less likely to overeat. Also, a high-fiber diet tends to make a meal "feel larger" and stay with you longer, so you have a sense of being full for a longer period of time.
What exactly is dietary fiber?
Wherever you find plant foods that your body can't digest or absorb … that's where you find fiber. Unlike other food components, such as fats, proteins or carbohydrates — which your body breaks down and absorbs — fiber isn't digested by your body. Instead, it passes relatively intact through your stomach, small intestine and colon and then out of your body.
Based on its ability to dissolve in water, fiber is usually classified as soluble, meaning that it does dissolve in water to form a gel-like material or insoluble, meaning that it doesn't dissolve.
Some common sources for fiber and the amounts you need
Soluble fiber sources include oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium – a fiber-laden seed used in a variety of supplements and health-related products. Insoluble fiber which promotes the movement of material through the digestive system is found in whole wheat flour, wheat bran, nuts, beans and vegetables including cauliflower, green beans and potatoes. A number of plant-based foods, most really, contain both forms of fiber though the amount varies.
Please note that refined or processed foods — such as canned fruits and vegetables, pulp-free juices, white breads and pastas, and non-whole-grain cereals — provide some fiber but in lower amounts. For fiber and nutrients in general, the less processing the greater the health value.
As far as amounts are concerned, the Institute of Medicine recommends that women who are 50 or younger consume 25 grams of fiber every day while women over 50 try to get 21 grams daily. For men, the suggested amounts are 38 grams and 30 grams respectively.
Some good ideas on getting the fiber you need
Start with breakfast: choose high-fiber breakfast cereals that include "whole grains," "bran" or "fiber" in the name or ingredients. You can also add some wheat bran to your cereal. Basically you want to start the day with 5 or more grams of fiber per serving.
Go whole on the grains: A good rule of thumb is to consume at least half of all the grains you eat in the whole grain form. That generally means whole wheat or another whole grain in bread and other baked goods plus brown rice, barley, whole-wheat pastas and bulgur. If you bake, be sure to substitute (or at least increase the amount of) whole-grain flour for white flour. You can also add crushed bran cereal, wheat bran or uncooked oatmeal to muffins, cakes and cookies.
Don't forget the legumes: Beans, peas and lentils are excellent sources of fiber. You can add kidney beans to soups or salads and there are a number of recipes out there for lentil soup. If you like nachos, mix them up a bit with refried or whole black beans, fresh veggies (red and green peppers are especially good), whole-wheat tortilla chips and fresh salsa.
An apple a day is just the beginning: Apples, bananas, oranges, pears and berries (fresh or frozen) are good sources of fiber. With a little creativity you can – and should – eat fruit at every meal. Breakfast is particularly easy because you can combine various fruits into a smoothie using a soy, non-fat dairy or juice base.
Some snacks you can feel good about: Fresh fruits, raw vegetables, low-fat popcorn and whole-grain crackers are all good choices. An occasional handful of nuts or dried fruits, separately or together, is also a healthy, high-fiber snack — although be aware that both are relatively high in calories.
A final word on fiber
If you feel you haven't been adding enough fiber to your diet, by all means start erasing the deficit. But don't start too quickly. Adding more fiber all at once can result in intestinal gas, abdominal bloating and cramping. So go slowly. Increase fiber in your diet gradually over a period of a few weeks, letting the natural bacteria in your digestive system adjust to the change.
And don't forget water. The benefits of fiber are highest when it absorbs water – and when you eat a wide variety of foods that contain it. The good news is that these foods are not only readily available, but they also make for some delicious and enjoyable eating.
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