Avoiding Nutritional Pitfalls in a Gluten-Free Diet: All About Fiber

Fiber and the Gluten-Free Diet

A gluten-free diet can contain enough fiber, but you will have to make an extra effort to choose foods that are good sources of fiber. Most Americans consume only half the recommended amounts of dietary fiber. Furthermore, in a typical American diet, grain foods (typically, yeast bread, ready-to-eat cereal, pasta, and flour) contribute over 25 percent of an adult's intake of fiber. Many people with celiac disease do not consume the recommended number of servings of grain foods. Processed grain foods that are included in a gluten-free diet may not be good sources of fiber—many gluten-free grain foods are made from refined flours and starches, which contain very little fiber.

Adding Fiber to Your Diet

All plant foods, including fruits, vegetables, legumes, and whole grains, contain fiber. Therefore, as you will see from the suggestions provided here, it is very easy to add fiber to your diet. There is one word of caution, however: it is best to add fiber to your diet gradually. A rapid increase in fiber intake can cause stomach and intestinal distress, including gas, bloating, and diarrhea—conditions that sometimes may be wrongly associated with a gluten reaction. But if you increase fiber intake gradually, you reduce the chance of developing these symptoms.

High-Fiber Fruits

According to Dietary Guidelines for Americans, 2005, the most recent edition of a guide published jointly by the U.S. Department of Health and Human Services and Department of Agriculture, a person requiring 2,000 calories a day should consume 2 cups (four servings) of fruit each day. A ½-cup serving of fruit is equivalent to ½ cup of fresh fruit or ¼ cup of dried fruit. While all fruits contain fiber, some are better sources than others. The following table identifies some of the best fruit sources of fiber per serving.

High-Fiber Vegetables

According to Dietary Guidelines for Americans, a person requiring 2,000 calories a day should consume 2½ cups (five servings) of vegetables each day. A ½-cup serving of vegetables is equivalent to ½ cup of cooked vegetables, ½ cup of raw vegetables, or 1 cup of raw leafy green vegetables. While all vegetables contain fiber, some are better sources than others. The following table identifies some of the best vegetable sources of fiber per serving.

Legumes: Dried Beans, Peas, and Lentils

According to Dietary Guidelines for Americans, a person requiring 2,000 calories a day should consume 3 cups of legumes (dried beans, peas, and lentils) a week. When you think of beans, you may think only of whole beans, but a variety of products are made from beans, including flour, pasta, and breakfast cereal.    

Gluten-Free Whole Grains

According to Dietary Guidelines for Americans, a person requiring 2,000 calories a day should consume six 1-ounce-equivalent servings of grain foods daily, and at least three of these servings should be whole grains. As I mentioned earlier in this chapter, whole grains contain all three components of the grain kernel: the outer fiber-rich bran layer, the nutrient-rich germ, and the starchy endosperm. Refined grains contain only the endosperm.

Science Class

Oats contain a type of dietary fiber called beta-glucan soluble fiber. Consuming at least 3 grams of this type of fiber from oats each day may reduce the risk of coronary heart disease by decreasing blood levels of cholesterol. The evidence supporting the cholesterol-lowering effects of oats prompted the Food and Drug Administration to allow a health claim for oats on food labels. Three grams of soluble fiber are found in 60 grams (¾ cup) of dry rolled oats. This amount is slightly more than the moderate amount (50 grams) of oats recommended for consumption for persons with celiac disease. If you are considering adding this grain to your diet, please read the section on oats (Chapter 2). If you do eat oats, they can be a great source of fiber, but be careful not to overdo it. Gluten-free whole grains include popcorn, brown rice, wild rice, whole-grain corn, buckwheat, amaranth, millet, quinoa, sorghum, oats, and teff. Look for products where one of these grains is listed as the first ingredient. Some gluten-free grain foods are made from a mixture of whole grains and refined grains. Use the nutrition label to choose products with at least 2.5 grams of dietary fiber per serving. One ounce (approximately 28 grams) of a gluten-free grain food is equivalent to one serving. For example, according to the food label on a particular brand of packaged brown-rice cakes, one rice cake weighs 9 grams. Therefore, a 1-ounce-equivalent serving of rice cakes would be approximately three rice cakes.