Fiber is a crucial part of a healthy diet. It supports good gut health, weight management and healthy digestion. Corey Tolbert, RD, LD, a licensed and registered dietitian at Piedmont, explains how to know if you’re getting enough fiber in your diet and what to do if you’re not.

The health benefits of fiber

“Fiber serves as food for healthy gut bacteria—it’s a prebiotic,” says Tolbert. “Your gut needs fiber for healthy bacteria to grow.”

Fiber can also support weight loss and weight management.

“Fiber helps you feel full, so you will be less likely to consume more calories than you need,” she says. “It also helps balance your blood sugar. If your blood sugar isn’t stable, you may be more likely to get hungry soon after a meal.”

The nutrient also plays an important role in the overall function of the digestive tract.

“Fiber can help reduce constipation and diarrhea,” says Tolbert. “It can also lower your risk of gastrointestinal cancers, like colon cancer and stomach cancer.”

Fiber also plays a role in healthy cholesterol levels. 

“Fiber draws ‘bad’ cholesterol out of your body and helps eliminate it,” she says.

How to know if you’re eating enough fiber

Regular bowel movements are a good indicator that you’re eating enough fiber. Ideally, you should have at least one bowel movement a day, says Tolbert, and your stool should look like types 3 and 4 on the Bristol Stool Scale.

The best high-fiber foods

The best sources of fiber include:

• Fruit, including raspberries, strawberries, oranges, apples, bananas, guava and mango

• Vegetables, such as broccoli, carrots, beets, Swiss chard, collard greens and artichokes

• Nuts, including pumpkin seeds, sunflower seeds, almonds, walnuts and pistachios

• Beans and legumes, like navy beans, white beans, kidney beans, garbanzo beans, lima beans, pinto beans, black beans, peas, lentils and soybeans (edamame)

• Whole grains, such as oatmeal, high-fiber cereal, quinoa and Kamut

Women should aim to eat 21 to 25 grams of fiber or more per day and men should target 30 to 38 grams per day or more, says Tolbert.

How to add more fiber to your diet without GI upset

If you don’t currently eat much fiber, you’ll want to gradually increase your intake to avoid uncomfortable gastrointestinal symptoms like bloating, gas, constipation or diarrhea.

“I recommend adding one serving of a high-fiber food each day,” says Tolbert. “Do this for three days, then add a second serving for three days. Gradually increase your intake from there.”

If you still have GI upset, she recommends to:

• Limit cruciferous vegetables, such as broccoli, cabbage and kale.

• Skip the fibrous peel on apples.

• Eat foods that are easier for the body to digest, such as bananas, rice, applesauce and toast.

• Cook your vegetables instead of eating them raw.

Most people should be able to gradually increase their fiber intake, but if you still notice digestive issues after following these tips, talk to your primary care provider or dietitian.

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