You may have heard that adding high-fiber foods to your diet can keep your digestive system regular. But fiber can do much more to improve your health, such as lowering blood pressure and cholesterol levels and helping with weight loss, too.

Understanding fiber in your diet

Fiber is a type of carbohydrate found mainly in fruits, vegetables, whole grains, and legumes (beans and peas). Your digestive system turns most carbs you eat into sugar. But fiber is different. It passes through your body without being broken down.

There are two types of fiber:

Soluble fiber dissolves in water and forms a type of gel in your stomach and colon that slows down your digestion and helps you feel full.

Insoluble fiber does not dissolve in water and typically remains whole as it passes through your digestive system. It helps to clear out your colon and improve your gut health.

How much fiber do you need?

According to the Dietary Guidelines for Americans 2020–2025 , the recommended amount of fiber that adults should get in their diet varies by gender and age. (Recommendations also vary for women who are pregnant or breastfeeding.)

Fiber naturally exists in the plants that we eat. Some manufacturers add it to the food they produce for added health benefits. You can see how much fiber packaged foods contain by reading the Nutrition Facts label . Dietary fiber is listed there under Total Carbohydrates.

Although fiber is an essential part of a healthy diet , most Americans don't get enough of it.

Benefits of a high-fiber diet

An important role of dietary fiber is to prevent constipation and support the movement of food through your body. Fiber adds bulk and absorbs water, which makes stool softer and easier to pass.

But fiber supports health in other ways, including:

Controlling blood sugar: Fiber-rich foods may keep blood sugar levels steady instead of causing them to spike.

Protecting heart health: Fiber may protect against heart disease in a number of ways, from fighting inflammation to helping keep blood pressure and cholesterol levels in check.

Helping to manage weight: Fiber helps you feel full for a longer time and can keep you from overeating.

Large studies have had mixed results about whether a fiber-rich diet reduces the risk of colorectal cancer. The evidence is stronger for whole grains, which are rich in fiber; increasing consumption of whole grains is associated with a decreased risk of colorectal cancer.

Which foods are high in fiber?

Fiber supplements are readily available, but it's best to get your fiber from food. That's because foods high in fiber also contain vitamins, minerals, and other nutrients your body needs.

Foods high in fiber include legumes, fruits, vegetables, whole grains, and nuts and seeds.

Legumes

Many people think "beans" and "legumes" mean the same thing, but there's a difference. While all beans are legumes, not all legumes are beans.

Legumes come from plants that grow their seeds in a pod. Peas and lentils are examples of high-fiber, non-bean legumes.

Whole grains

There's a difference between whole grains and refined grains. Whole grains contain the entire grain, which includes bran and germ, while refined grains have been processed in a way that removes the bran and germ. Whole grains are an excellent source of fiber.

You can't tell which foods are whole grain just by color. Check to see if "whole" or "whole grain" appears as one of the first three ingredients on the ingredient list.

Tips for increasing fiber in your diet

There are easy ways to get more fiber in your diet:

Slice up raw vegetables to keep in your refrigerator as snacks.

Choose whole-grain cereal or a bowl of oatmeal for breakfast, and top it with berries or almonds.

Add beans, shredded carrots, and a sprinkling of nuts and seeds to your salad.

Include a piece of fruit or vegetable as part of each meal.

Switch from white rice to brown and from white bread to whole-grain.

Try whole-wheat pasta instead of regular.

Experiment with international dishes that use whole grains and legumes, such as Middle Eastern cuisines.

Try to eat some fiber-rich foods with each of your daily meals.

Adding fiber in your diet too quickly can cause digestive side effects like bloating and constipation. If you need to boost your fiber intake , increase it slowly, over time. And drink plenty of water, which can help fiber pass through your digestive system without stomach distress.

Lisa Catanese, ELS, has been a medical writer for more than 20 years. Through her company, Blue Blaze Communications, she has written content for hospitals, magazines, websites, pharmaceutical companies, and medical education companies, and her writing … See Full Bio View all posts by Lisa Catanese, ELS Teresa Fung is an adjunct professor at the Harvard T.H. Chan School of Public Health. She received her BS and MS in nutrition from Cornell University, and her ScD in both nutrition and epidemiology from HSPH. She … See Full Bio View all posts by Teresa Fung, MS, RD, ScD As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

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