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Fiber

Medically reviewed by: Mary L. Gavin, MD

Fiber is one of those good-for-you nutrients. But what exactly is it? Why do you need it and what food should you eat to get it?

What Is Fiber?

Fiber is a carbohydrate that the body can't digest. It's found in the plants we eat — fruits, vegetables, grains, and legumes.

Fiber can be soluble or insoluble:

  • Soluble fiber dissolves in water. It helps lower cholesterol and improve blood sugar control.
  • Insoluble fiber does not dissolve in water. It helps with constipation.

Both kinds of fiber are important parts of a healthy diet.

What Are the Benefits of Fiber?

A diet high in fiber:

  • helps prevent or relieve constipation
  • increases feelings of fullness, which may help with weight control
  • lowers cholesterol
  • helps prevent heart disease and diabetes
  • may lower the chances of getting some types of cancer

What Are Good Sources of Fiber?

Foods that are naturally high in fiber, include:

  • whole grains, such as 100% whole-wheat bread, brown rice, and oatmeal
  • cooked dried beans, such as black beans, lentils, and split peas
  • fruit and vegetables
  • nuts and seeds

Look for the fiber content of foods on the nutrition labels — it's listed as part of the information given for "total carbohydrates." Choose foods with 3 grams of fiber or more.

How Much Fiber Do I Need?

Teen girls should get about 25 grams of fiber per day and teen guys should get about 31 grams of fiber per day.

It's best to get your fiber directly from foods rather than from pills or other supplements. The best sources are fresh fruits and vegetables, nuts and legumes, and whole-grain foods. If your doctor recommends a fiber supplement, take it as directed.

Other things to know:

  • Add fiber to your diet slowly over a few weeks. Adding too much fiber too quickly can cause bloating, gas, and/or cramps.
  • Drink plenty of water, which helps move fiber through the intestines.

Making Fiber Part of Your Diet

Here are some simple ways to make sure you get enough fiber.

Breakfast:

  • Have a bowl of hot oatmeal.
  • Choose whole-grain cereals that list ingredients such as whole wheat or oats as one of the first few items on the ingredient list.
  • Top fiber-rich cereal with apples, oranges, berries, or bananas. Add almonds to pack even more fiber punch.
  • Try bran or whole-grain waffles or pancakes topped with apples, berries, or raisins.
  • Enjoy whole-wheat bread, bagels, or English muffins instead of white toast.

Lunch and Dinner:

  • Make sandwiches with whole-grain breads (like oat or wheat) instead of white.
  • Use whole-grain spaghetti and other pastas instead of regular.
  • Try wild or brown rice with meals instead of white rice. Add beans (kidney, black, navy, and pinto) to rice dishes for even more fiber.
  • Spice up salads with berries and almonds, chickpeas, cooked artichokes, and beans (kidney, black, navy, or pinto).
  • Add lentils or whole-grain barley to your favorite soups.
  • Include veggies with your meals.
  • Take fresh fruit when you pack lunch for school. Pears, apples, bananas, oranges, and berries are all high in fiber.

Snacks and Treats:

  • Top yogurt, cereal, or oatmeal with fruit and nuts.
  • Put veggies, like lettuce, tomato, or avocado, on sandwiches.
  • Add beans to soups and salads.
  • Add bran to baked goods.
  • Choose air-popped popcorn, whole-grain crackers, fruit, or vegetables as healthy snack options.
Medically reviewed by: Mary L. Gavin, MD
Date reviewed: May 2022