How Fiber Helps Your Digestive Health

Medically Reviewed by David Kiefer, MD on July 24, 2015
2 min read

Have you been told to eat more fiber? Most Americans don't get enough of it.

Turns out it’s one of the most important foods in your diet. It helps keep your digestive system running smoothly. That's why you need fiber even if you don't have a problem with constipation.

Women under 50 years old should get 25 grams daily, and men under 50 should have 38 grams.

Fill up on the top reasons it's so good for you.

“We spend a lot of money on laxatives in this country,” says Joan Salge Blake, RD, a clinical associate professor of nutrition at Boston University. But the best way to stay regular is to simply eat more fiber. It helps bulk up your stools, and keeps waste moving through your intestines, preventing constipation.

Just be sure to drink lots of water. “For fiber to work, you've got to hydrate it in your body,” Blake says. “You need plenty of fluid to move [waste] along or it can build up.”

You may have heard of probiotics -- so-called “good” bacteria found in fermented foods (like yogurt). They help improve digestive health, among other perks.

But what about prebiotics? These are essential fibers that help those probiotics flourish inside your intestines.

“It's food for the bacteria. They feed off of it,” Blake says. Prebiotics are found in fiber-rich foods, like fruits and vegetables, although not all fiber has prebiotics. Some of the best sources: bananas, whole wheat, and corn.

High-fiber foods are a satisfying weapon against snack cravings.

“You feel full faster, [and] you feel full for longer,” says Wanda D. Filer, MD, a family doctor in York, PA. “You might find that you lose a few pounds.”

While some fiber-rich foods like nuts are high in calories, many others like popcorn aren't. “It will fill you up before it fills you out,” Blake says. “It displaces other calories.”

A high-fiber diet can help lower your chances of getting a serious gut problem like diverticulitis. With this condition, pouches in the wall of the colon cause waste to become trapped. This can lead to inflammation or infection. Doctors aren’t sure what causes the problem, but research shows that eating a lot of fiber keeps waste moving through your system.

Fiber can also help ease the symptoms of some types of irritable bowel syndrome. It does that by helping control your digestive system and lowering your risk of getting constipation.

And people who have gastroesophageal reflux disease (GERD), which causes heartburn, may feel better if they switch to a high-fiber diet, some studies show.

It can also help cut your risk of certain cancers, lower your cholesterol, and help keep your blood sugar balanced.

If your doctor suggests that you get more fiber, it’s important to go slow. Adding too much too quickly can overwhelm your gut, causing bloating and cramping.