EATING RIGHT : The Trouble With Snack Bars

Dear Eating Right: I usually don’t have time for an elaborate breakfast, so I eat a snack bar when I’m in a hurry. Are they a good source of fiber?

--ELIZABETH

Dear Elizabeth: Snack and fiber bars are promoted as an easy way to increase the amount of fiber you eat. But frankly, they are little more than cereal bound together with fat; the convenience is hardly worth the fat.

An average fiber bar contains 100 to 120 calories, about four grams of fiber and five to six grams of fat. Eat the chocolate-coated variety and the calories soar to 150 with seven grams of fat. The fiber content is about the same as a breakfast bar. Generic granola bars have even less fiber. In the same amount of time, you could eat a medium apple for just 80 calories and get four grams of fiber and less than a gram of fat. Or have a quick cup of bran flakes cereal and nonfat milk at just 190 calories, six grams of fiber and less than two grams of fat.

Fibrous foods are associated with good health for an assortment of reasons. Populations that eat a lot of fiber have a low incidence of diverticulitis, irritable colon, hernia, hemorrhoids, colon cancer, heart disease, obesity, diabetes, dental caries and gallstones. In this country, one-third of all cancer deaths may be related to the foods we eat, health experts say, and fiber plays a major role in reducing this risk. Here’s how.

Dietary fiber , roughage and bulk are terms that refer to the undigestible part of plants. This residue resists digestion and acts like a kitchen broom, sweeping the intestines and colon clean of cancer-causing wastes. It reduces constipation. At the same time, it fills the stomach and makes you feel less hungry, so you eat fewer fatty foods. Obesity and too much fat in the diet are other risk factors for cancer, health experts say.

There are two types of fiber: water-soluble and water-insoluble. Each has its own merits and function in the body.

Insoluble fiber is found in wheat bran, peas, dried figs, beans and legumes. It is the thread- or wood-like part of the husks and shells. Insoluble fiber is not capable of holding onto water particles, so it moves quickly through the digestive system.

Soluble fiber also aids digestion, but it may have a role in reducing blood cholesterol levels as well. Unlike insoluble fiber, it is found in the cell walls of oats, apples, pears and citrus fruits. It dissolves in water and forms a gel-like substance that slows digestion.

(For this reason, soluble fiber in oats has been the focus of a great deal of attention recently. Subsequent studies, however, have shown that soluble fiber in pectin, barley, psyllium and beans are as effective as oats in lowering cholesterol levels.)

But there’s a warning against eating too much fiber. The American Dietetic Assn. discourages intake above 50 grams of fiber daily; eating too much fiber can affect mineral absorption and cause gastrointestinal discomfort.

For maximum benefit, both ADA and the American Cancer Institute suggest Americans eat 35 grams of fiber daily. (Americans currently eat about 11 grams of fiber each day, the equivalent of about a cup of kidney or navy beans.)

A simple way to meet this goal is to munch on fresh fruits and raw or lightly steamed vegetables, and eat whole grains, pastas, breads and cereals. You can substitute, for example, whole-wheat toast with one-half pat butter and one teaspoon jam for white toast and a full pat of butter. This will add three grams of fiber to the daily fiber total. Or substitute one-half cup cooked green peas, which supply nearly eight grams of fiber, for green beans, which have less than two grams of fiber.

If you must have a muffin or bar type of food, try making your own and freezing them to cut down on fat and sugar. Reduce the sugar by half or use this formula from the Tufts University Diet and Nutrition Letter: one to two tablespoons sugar per cup flour in muffins; one half cup in cakes; two tablespoons fat per cup flour in cakes and cookies or no more than two tablespoons oil; one to two tablespoons per cup for muffins and quick breads.