Don't Forget the Fiber in Your Low-Carb Diet

The low-carb food craze could cost some people an important part of a healthy diet: fiber.

There's no doubt that fiber is good for you. The problem is that it comes with carbohydrates attached. "The onslaught of high-protein diets is pushing people further away from foods with fiber," says nutritionist Leslie Bonci, M.P.H., R.D. And the trend comes just as doctors and dietitians are recommending people eat more fiber-filled foods.

Fiber is found in fruits, vegetables, grains and legumes. Some fiber is soluble, meaning it partially dissolves in water. Insoluble fiber doesn't dissolve in water.

Studies show fiber offers a lot of benefits, says Ms. Bonci, a spokeswoman for the American Dietetic Association (ADA) who wrote "The ADA Guide to Better Digestion." A fiber-rich diet may decrease the risk for cardiovascular disease among older individuals, she says. Fiber may help stabilize blood sugar levels for insulin-dependent diabetics and may lower the risk for developing type 2 diabetes. It may help reduce body mass index and weight, and cut the risk for diverticular disease and constipation.

Although eating more fiber has been touted as a good way to help prevent colorectal cancer, more recent -- and more comprehensive -- studies have concluded that fiber has little if any effect on reducing the risk for this cancer.

Insoluble, soluble

Whole wheat and wheat bran, corn bran, many vegetables, and skins of fruits and root vegetables contain insoluble fiber -- roughage -- that helps move waste more efficiently through your digestive system. That's half of the fiber story and a good reason to eat that summer-fresh corn on the cob.

Soluble fiber, the other half of the story, abounds in dried beans and peas, oats, barley, and fruits and vegetables. It binds to fatty substances in the digestive tract and helps you get rid of them. Soluble fiber helps you lower blood cholesterol levels and regulate the use of sugars.

"You need a combination of soluble and nonsoluble fiber for a good diet," Ms. Bonci says. "Soluble fiber has more of an impact on cholesterol and blood glucose. Insoluble fiber is good for bowel health."

Yet most of us get less than half the fiber we need. "Most adults are getting only 10 to 12 grams of fiber per day," she says. You should get a minimum of 20 to 35 grams of dietary fiber a day. For children older than 2, their fiber intake should equal their age plus 5 grams.

You don't need a lot more fiber to make a difference, Ms. Bonci says. In fact, it's better not to add a lot of high-fiber foods at once.

Ms. Bonci recommends you add no more than 5 grams a day to start. That's not much, when you consider a half-cup serving of a fruit or vegetable is likely to contain 2 grams.

A good place to make a change is breakfast. You can add a fruit or choose a cereal with more whole grains, Ms. Bonci says.

Finding fiber

Beans are best. Kidney, navy, black, cannellini, chickpeas, lentils -- beans of any variety in any form provide healthy soluble fiber. A bonus: Beans also have potassium, helpful in managing blood pressure.

Nuts to you. Nuts contain fat, but they also provide fiber and protein. A quarter cup of nuts averages 3 grams of fiber, says Ms. Bonci.

Berry, berry good. Summer melons have some fiber, but berries and kiwi have the most. Thank the person who gives you a raspberry.

Veg out. Grill them, marinate them, steam them, but eat your veggies. Combine them with beans or add them to a pasta salad.

Feel your oats. If you make meatloaf, hamburgers or meatballs with breadcrumbs, try oatmeal instead. Use a coffee grinder to pulverize it -- the fiber remains.

Shop smart. It's getting easier to find whole-grain foods. Whole-wheat pasta and multigrain English muffins stand out. If brown rice has become your standard, look for other grains to vary taste and texture. Try buckwheat or quinoa.

Pull out a plum. People didn't like the word prune, so growers did a marketing fix. Now they're dried plums. Yes, they have fiber. A half-cup of prune juice has 8 grams, plus other substances that work as a laxative.