5 reasons to eat more fiber

With dour nicknames like “roughage” and “bulk,” few terms in the nutrition world sound less sexy than fiber. But "the benefits of fiber are about as valuable as you can get," says Lauren Slayton, M.S., R.D., a dietitian in New York City.

This humble dietary workhorse is definitely overdue for some love: Fiber is among the most underconsumed nutrients in the U.S. The exact amount you need depends on your age and sex — the low end of the range is 21 grams for women over age 50, and the high end is 38 grams for men in their 20s. Want to see how you’re doing with that goal? Weight Watchers members can just open the WW app: When you track your meals, the app shows you how much you’re getting (alongside your target). Here’s why those grams matter so much, plus ways to up your intake.

Key takeaways

• Fiber is a type of carbohydrate found only in plant foods, and most adults fall short of the recommended amount.

• Eating a high-fiber diet is linked to several important health benefits, including a lower risk of type 2 diabetes, heart disease, and certain cancers.

• Fiber also keeps your digestive system running smoothly and may support long-term weight management by helping you feel full.

• To get more fiber, fill your plate with fruits, vegetables, and whole grains, and choose whole foods over supplements whenever possible.

Fiber is one of three main classes of carbohydrates. Unlike its cousins, though — starches and sugars — fiber doesn’t provide glucose energy. Since our bodies are unable to process fiber for fuel, we use it in other ways, explains Angel C. Planells, M.S., RDN, a dietitian in Seattle.

Dietary fiber can be divided into a number of subtypes: There’s pectin in pears and apples, inulin in onions, and cellulose in corn, for example. But it’s typically classified as either soluble or insoluble, depending on how it interacts with water.

• Soluble fiber absorbs water in the digestive tract to form a gummy material. It’s found in cereal grains such as oats, and pulses including beans, lentils, chickpeas, and peas.

• Insoluble fiber doesn’t dissolve in water; it provides volume and bulk to stool and helps keep contents moving through the digestive tract. Insoluble fiber is found in whole grains, nuts, beans, and vegetables.

Notice a trend in those food examples? Fiber occurs naturally only in plants — think fruits, veggies, whole grains, seeds, nuts, and legumes. Unless it’s part of an added ingredient, you won’t find fiber in dairy, meat, poultry, seafood, or eggs.

No question: Fiber is pretty great for human health. Published research points to a slew of positive impacts associated with a fiber-rich diet. Here’s a look at some of the biggies:

1. Reduces risk of type 2 diabetes

Large studies have shown that adults who consistently meet or exceed their daily fiber targets are 20% to 30% less likely to develop type 2 diabetes over time. Researchers have noted a number of potential reasons, including insoluble fiber’s ability to improve insulin sensitivity (insulin resistance is a major risk factor for type 2 diabetes). Fiber can also be helpful for people already living with the condition, Planells notes. “Soluble fiber slows the absorption of glucose from food,” he says. “This can be helpful in regulating blood sugar levels.”

2. Supports heart health

OK, this one isn’t exactly news. Health experts have long known about the association between high fiber intake and reduced incidence of coronary heart disease. One likely reason? A high-fiber diet can improve cholesterol numbers. Soluble fiber in particular appears to play a key role in decreasing levels of low-density lipoprotein (LDL) cholesterol — the harmful kind that builds up in blood vessels. With a spongelike effect, the fiber soaks up excess cholesterol in the gut and removes it from the body, helping to keep your arteries clear, Planells explains. What’s more, high fiber intake may improve blood pressure in both healthy adults and those who are living with hypertension.

3. May lower cancer risk

Some evidence suggests that fiber-rich diets may help protect against certain types of cancer. Research has found that women who consumed the highest amounts of fiber were 8% less likely to develop breast cancer than those who consumed the least. The finding held for both premenopausal and postmenopausal breast cancers.

Meanwhile, multiple studies have found that diets high in fiber are associated with a decreased risk of developing colorectal cancer. Fiber helps to move waste through the colon, supports a healthy gut microbiome, and reduces inflammation in the colon, all of which can support colon health.

4. Aids digestive function

Real talk: Does the word “fiber” automatically make you think of the poop emoji? Fair. Fiber is most famous for supporting laxation, better known as going number 2. In taking on water, soluble fiber helps form soft, bulky stools. Insoluble fiber adds further bulk and helps sweep waste material through the body’s plumbing. Fiber is especially worth watching if you take a GLP-1: Constipation is often reported as a common side effect, and fiber may help.

But that’s not the only digestive trick up fiber’s sleeve. You know your gut microbiome — the trillions of bacteria living in your digestive tract? Well, those microbes need something to munch on. After passing through the upper part of the intestine undigested, fermentable fiber types (such as pectin and inulin) become food for the bacteria that live in our gut, Slayton says. As probiotics chow down on the bounty, some produce short-chain fatty acids believed to play a role in immunity, inflammation control, and more. Other gut bacteria may use their fiber fill-up to influence appetite-related hormones. “Just as we perform better when fed and nourished, the same can be said for probiotics," says Slayton.

5. Supports healthy weight management

All signs point to fiber being helpful for weight loss and long-term weight management. Research shows that greater fiber intake can support weight loss and reductions in waist circumference.

That’s not to say people who boost their fiber intake will magically lose weight, Planells clarifies. The weight effect is likely tied to fiber’s influence on our appetite and broader eating patterns: By filling us up and supporting a sustained release of energy from food, fiber may make us less likely to have seconds at mealtime, for example, or experience major munchies at bedtime.

Stock your kitchen with your fav high-fiber foods 

Boosting fiber intake comes down to a pretty simple practice: Putting plenty of plants on your plate each day, including fruits, vegetables, whole grains, and pulses. Slayton’s personal fiber-rich faves include:

• Lentils (8 g of fiber per ½ cup cooked)

• Broccoli (5 g per cup cooked)

• Cauliflower (3 g per cup cooked)

• Sweet potato (4 g per medium potato, baked with skin)

• Cabbage (3 g per cup cooked)

• Brussels sprouts (4 g per cup cooked)

Give your go-to meals a fiber boost  

Putting more high-fiber recipes into your rotation makes it easy to get more of the nutrient — but making small tweaks to the meals you turn to regularly works too.
 

Tip #1: Leave tender skins on fruit and vegetables and eat the items whole. Outer peels often contain a concentration of fiber, Slayton says.

Tip #2: Mix up your pasta game by making dishes with alternanoodles high in fiber — think minty pea pasta with chickpea rotini, or beefy Bolognese with a lentil-based noodle.

Tip #3: Instead of croutons, crumble baked, fiber-boosted chips, such as Zesty Z Fiber Pita Chips, onto salads for crunch.

Tip #4: Try grain-rich recipes that incorporate bulgur, barley, quinoa, farro, wild rice, buckwheat, or millet. And when shopping for grains, pasta, or other packaged products, be sure to read the Nutrition Facts panels for details on the fiber content.

Tip #5: Make a batch of fiber-rich trail mix, tossing together whole-grain cereal, dried fruit, and nuts. Portion out servings to stash in your glove compartment, desk drawer, or tote bag.

Tip #6: Instead of sour cream, try using veggies or beans to make a flavorful snack dip. Options such as white beans, roasted eggplant, and sweet red peppers make delicious bases for dunking.

Tip #7: Sub in bran cereal or rolled oats for traditional breadcrumbs in meatloaf.

Tip #8: Sprinkle toasted nuts and seeds onto salads.

Fiber supplements may be helpful for some people when their diets fall short. Still, those capsules and powdered drink mixes aren’t a perfect replacement for whole foods. “When I consume a piece of fruit, I get not just the fiber, but the vitamins, minerals, antioxidants, and the fluid that come with the fruit,” Planells says. “If I take the supplement, I only get fiber.” If you think you might benefit from a fiber supplement, chat with your doctor.

Fiber is a carbohydrate found in many plant-based foods, including fruits, veggies, and whole grains. Eating plenty of fiber can help reduce your risk for serious health conditions like type 2 diabetes, improve your heart health by lowering cholesterol, and keep your digestive system happy. Fiber may also help you maintain a healthy weight since it can help keep you feeling full. While most women should get 21-25 grams of fiber a day, with men’s target being 30-38 grams, many fall short. Curious how much fiber you’re actually getting? Weight Watchers members can check the WW app, which automatically tracks key nutrients like fiber whenever you log your meals.