There’s more to a healthy gluten-free diet than simply avoiding wheat, barley, and rye. Cherie Gough explains why getting enough fiber is essential when you follow a gluten-free way of eating.
In 2017, a Reader’s Digest headline—“if you want to avoid heart disease, don’t even think of going gluten-free”—grabbed attention but misrepresented the research. The study behind the piece found that many gluten-free diets include fewer cardioprotective whole grains than the standard Western diet, which could affect heart-disease risk. The real issue, however, is not gluten avoidance itself but the common pattern of replacing whole grains with processed, low-fiber products. A gluten-free diet that emphasizes processed foods instead of whole, fiber-rich options is the version that raises health concerns.
Dr. Sheila Crowe, director of the Celiac Disease Clinic at the University of California, San Diego, concurs: “A well-balanced, naturally gluten-free diet is healthy. As with any diet, it’s the processed items that make it less healthy.”
I learned this personally after my daughter was diagnosed with celiac disease at age four. To manage her condition we switched to many packaged gluten-free products. At first she improved—more energy and better growth—so I assumed packaged substitutes were working. But when an X-ray revealed severe constipation that could have required hospitalization, I realized our diet needed a serious rethink. A simple over-the-counter remedy helped then, but the experience pushed me to consult a dietitian.
The dietitian’s guidance was straightforward: drink plenty of water and choose more whole, unprocessed, plant-based foods rich in fiber. We followed that advice, and her digestive health improved.
The Importance of Fiber in a Gluten-Free Diet
Fiber has long been recognized as essential for good health, yet most Americans fall short of recommended intake. Robynne Chutkan, author of The Microbiome Solution, notes that most people consume only about half of the recommended 25 to 35 grams of fiber per day, and much of it comes from less beneficial processed sources.
For people avoiding gluten, meeting fiber targets can be even harder. Dr. Jessica Madden, a pediatrician with celiac disease, points out that many gluten-free alternative flours simply contain less fiber than wheat flour. Lori Welstead, registered dietitian at the University of Chicago Celiac Disease Center, adds that many people depend on gluten-free breads, wraps, and crackers for fiber, but those swap-outs usually provide far less fiber than whole-wheat products. People eating standard wheat-based products often get 8 to 10 grams of fiber a day even from inexpensive wheat bread—something not easily matched by many gluten-free processed items.
Dietary fiber is the indigestible portion of plant foods found in fruits, vegetables, legumes, and whole grains. Because the body doesn’t absorb it, fiber helps move material through the digestive tract. There are two main types: soluble fiber dissolves in water to form a gel that can help lower cholesterol and regulate blood sugar; insoluble fiber adds bulk and aids regular bowel movements. Both types are important for digestive and overall health.
How to Get Enough Fiber on a Gluten-Free Diet
If you need to avoid gluten, there are many naturally gluten-free, fiber-rich choices. Dr. Alessio Fasano of the University of Maryland Celiac Research Center highlights oats as an excellent, fiber-rich whole grain that’s generally well tolerated by most people with celiac disease—about 95 percent, he says—though a small number may react. Oats are particularly high in soluble fiber. To minimize cross-contamination, choose oats produced under a strict purity protocol where growing, processing, and transport are kept gluten-free.
Welstead recommends teff, millet, quinoa and fiber-dense seeds such as chia, flax, and hemp. Some patients do better on a Paleo-style plan that excludes grains and legumes; for them, a higher intake of fruits and vegetables is important to meet fiber needs. My daughter’s dietitian, Abbey Ricchiuto-Corpuz, describes fiber as a “toothbrush for the gut” and encourages daily, consistent fiber intake rather than occasional boosts. Beans are a favorite for adding soluble fiber—one cup averages about 13 grams—and are easy to incorporate into salads, soups, stews, curries, or dips like hummus.
Brown rice contains modest fiber—about 2 grams per half cup cooked—but rice can also carry variable amounts of inorganic arsenic, a contaminant of concern. Because many gluten-free products use rice flour, people on gluten-free diets may be exposed to more arsenic than those eating a standard Western diet, so diversifying fiber sources is wise.
Heart Disease Prevention
The heart-health study that sparked the Reader’s Digest headline underscores a key point: whole grains appear to offer cardioprotective benefits. Dr. Peter Green of Columbia University, who helped conduct that research, advises working with a dietitian when following a gluten-free diet for medical reasons and deliberately including alternative whole grains and other wholesome, fiber-rich foods to support heart health.
Fiber and the Gut
Research also links fiber to a healthy gut microbiome. A Harvard study in Pediatrics (February 2016) noted that intestinal flora—beneficial bacteria that rely on fiber—play a central role in nutrient absorption. Without sufficient fiber the microbiome’s function suffers, increasing the risk of malabsorption and inflammation-related problems.
Aim to “eat the fruit-and-vegetable rainbow,” include beans and other naturally gluten-free, high-fiber foods daily, and experiment with oat-flour recipes and other fiber-forward dishes to make meeting your fiber needs both enjoyable and sustainable.
Fiber High Five
Want to add more fiber to your diet? Try these practical tips.
- Start Slow
Increase fiber gradually—about 5 grams per day—to avoid bloating and discomfort while working toward 25 to 30 grams daily. - Hydrate
Drink about eight 8-ounce glasses of water daily to support fiber’s passage through the digestive system. A squeeze of citrus can add flavor and a small boost of soluble fiber. - Find Fiber-Fabulous Foods
Choose high-fiber foods you enjoy so you’re more likely to stick with them. Incorporate favorite snacks and recipes that use fiber-rich ingredients. - Keep a List
Make a reference list of naturally gluten-free, high-fiber foods and consult it when planning meals and shopping to ensure variety. - Track Your Progress
Record fiber intake in a planner or use a nutrition app to monitor how much fiber you’re consuming and stay on target.
Fiber-Friendly Eat Sheet
| FOOD | SERVING SIZE | GRAMS OF FIBER* |
| Adzuki beans, boiled | 1 cup | 16.8 |
| Almonds, skin-on | 23 nuts | 4 |
| Apple, with skin | 1 medium | 4.4 |
| Artichoke, cooked | 1 medium | 6.8 |
| Avocado, raw | 1 medium | 9.8 |
| Baked beans, vegetarian, canned | 1 cup | 9.8 |
| Black beans, boiled | 1 cup | 15 |
| Broccoli | 1 cup | 2.4 |
| Carrots, raw and sliced | 1 cup | 3.4 |
| Cauliflower | 1 cup | 2.1 |
| Chia seeds | 1 tablespoon | 5 |
| Chickpeas, boiled | 1 cup | 12 |
| Coconut | 1 cup | 7.2 |
| Edamame, fresh, boiled | 1 cup | 8 |
| Figs, raw | 2 | 2.8 |
| Flaxseeds | 2 tablespoons | 5.6 |
| Gluten-free rolled oats | ½ cup | 4 |
| Green peas, frozen, cooked | ½ cup | 3.6 |
| Hemp seeds | 1 tablespoon | 1.6 |
| Hummus | ½ cup | 7.4 |
| Kidney beans | 1 cup | 13.1 |
| Lentils, boiled | 1 cup | 15.6 |
| Millet, cooked | 1 cup | 2 |
| Oatmeal, cooked | 1 cup | 4 |
| Potatoes, with skin | 1 large | 6.6 |
| Raspberries | 1 cup | 8 |
| Parsnips | 1 cup | 5.6 |
| Pear, with skin | 1 medium | 5.5 |
| Popcorn, air-popped | 4 cups | 3 |
| Psyllium husks | 1 tablespoon | 4.5 |
| Quinoa, cooked | 1 cup | 5 |
| Refried beans | 1 cup | 11.4 |
| Split peas, boiled | 1 cup | 16.3 |
| Turnip greens, boiled | 1 cup | 3.1 |
*Data from the USDA National Nutrient Database for Standard Reference, Release 27; fiber content can vary among brands.