8 Reasons to Add Fiber to Your Diet

Two Types of Fiber

There are two types of fiber – soluble and insoluble – both are important to have in your diet.

• Soluble fiber dissolves in water and forms a gel-like substance in your stomach, which slows down digestion. Soluble fiber is found in foods such as oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables.^1,5
• Insoluble fiber does not dissolve in water and remains mostly intact as it passes through your GI tract. It adds bulk to the stool and helps with the passage of digested food through the stomach and intestines. Insoluble fiber is found in foods such as wheat bran, vegetables (non-starchy), and whole grains.^1,5

Most high fiber foods contain both soluble and insoluble fiber, so you don’t have to think too much about which type to choose, instead focus on your overall fiber intake.⁶ Fiber-rich foods include whole grains, vegetables, fruits, beans, peas, lentils, nuts, and seeds.⁷ For a more comprehensive list of fiber-rich foods, see the Dietary Guidelines for Americans Food Sources of Dietary Fiber.

Health Benefits

Adding fiber to your diet can yield numerous health benefits. Here are 8 reasons why it’s worth prioritizing.

1. Improved Digestive Health

Fiber plays a critical role in maintaining a healthy gastrointestinal (GI) system. Insoluble fiber, found in whole grains and the skins of fruits and vegetables, adds bulk to stool, promotes regular bowel movements, and prevents constipation. These actions support colon health and may reduce the risk of diverticular disease.⁸

2. Weight Management

By slowing down digestion, high-fiber foods can help you feel full longer after you eat. This helps reduce overeating and thus reduces overall calorie intake. Studies have found a correlation between higher fiber intake and lower rates of obesity.^3,9,10,11,12

3. Blood Sugar Control

Soluble fiber slows the absorption of sugar in the digestive system, stabilizing blood glucose levels and improving insulin sensitivity. This makes it particularly beneficial for individuals managing or at risk of type 2 diabetes.^7,11,13,14

4. Lower Cholesterol Levels

Soluble fiber binds to bile acids in your digestive tract, preventing their reabsorption into your body and promoting their excretion. Since bile acids are made from cholesterol, your liver has to use more cholesterol to make new ones. This helps lower your total cholesterol levels, including “bad” LDL cholesterol, which is good for your heart health.^3,15,16

5. Enhanced Gut Microbiome & Immune Function

Soluble fiber, particularly prebiotic fibers (fibers that get fermented in the gut), serves as food for beneficial gut bacteria.⁷ These fibers help foster a healthy gut microbiome, which has been linked to improved immunity, better digestion, and even enhanced mental health.⁸ Beneficial bacteria produce short-chain fatty acids (SCFAs) that reduce inflammation and support colon health.^8,17,18

6. Reduced Risk of Cardiovascular Diseases

A high-fiber diet has been associated with a lower risk of heart disease and stroke. Fiber can help reduce blood pressure, improve cholesterol levels, and decrease inflammation, all of which support cardiovascular health.^11,15

7. Reduced Risk of Certain Cancers

High fiber intake has been linked to a decreased risk of several cancers, especially colorectal cancer, by promoting a healthy gut environment and reducing inflammation. The production of short-chain fatty acids (SCFAs) and timely and proper waste elimination may collectively lower carcinogenic activity in the colon.^11,19

8. Comprehensive Chronic Disease Prevention

Regular fiber consumption has been inversely associated with the risk of most diet-related chronic diseases such as obesity, type 2 diabetes, certain cancers, and cardiovascular diseases.^19,20 By supporting healthy digestion, weight management, and metabolic health, fiber plays a key role in long-term disease prevention.

Reaping the benefits of fiber

To reap the full health benefits of dietary fiber, aim to consume a variety of plant-based foods, ensuring a balance of both soluble and insoluble fibers.

Add fiber gradually

If you haven’t been eating much fiber, be sure to increase gradually – adding too much too quickly can lead to bloating, gas, constipation, or stomach cramps. Gradual increases allow your digestive system to adjust to the higher fiber content, reducing the likelihood of these side effects. To increase fiber gradually, try adding a small portion of high-fiber foods to your meals each day, such as fruits, vegetables, whole grains, or legumes. Increase your fiber intake by 5 grams every few days until you reach the recommended daily intake. This approach can help maximize the benefits of fiber while minimizing any unpleasant side effects.

Hydrate

Fiber works best when you’re adequately hydrated, as it absorbs water to help move food through the digestive tract. Increasing water intake alongside fiber helps prevent constipation or discomfort.²¹

Choose a variety of fiber-rich foods to be sure you’re getting both types of health-benefitting dietary fiber. Strive for the recommended daily dietary fiber intake from whole food sources to support digestion, heart health, and overall well-being.