Cedars-Sinai Blog

Why is Fiber Essential for a Healthy Diet?

fiber, food, fruit, vegetables, diet

If you're like most Americans, you're not getting enough fiber in your diet.

According to the American Journal of Lifestyle Medicine, only 5% of Americans consume the required amount of fiber each year. 

"An adequate fiber intake is associated with reduced risk for heart disease, stroke, hypertension, certain gastrointestinal diseases, obesity, type 2 diabetes, and certain cancers."

To help understand why we aren't getting enough fiber and what effect it has on the body, we talked to Cedars-Sinai clinical dietitian Erika Der Sarkissian.

Q: Why aren't we getting enough fiber?

Erika Der Sarkissian: Unfortunately, the standard American diet consists of a lot of processed meat, fried foods, and refined grains—all of which have little to no fiber. Many of us lack vegetables, fruits, nuts, seeds, and whole grains, all of which are great sources of fiber.

Q: How much fiber should we be consuming?

EDS: We should get about 25-30 grams a day from food and the average American gets about half that.

Q: Which foods should we make sure to eat?

EDS: At lunch and dinner, try to fill half your plate with fruits and vegetables. You can choose a variety of different colors and textures to fit your taste. 

Fresh, frozen, or canned fruits and vegetables can also be healthy options and provide fiber, but watch out for added sauces/salt. 

Nuts and seeds and legumes—like black beans, chickpeas, and lentils—can be great high-fiber additions to salads, meals, or snacks.

Q: Which foods should we avoid?

EDS: I think with all the fad diets that include limiting or eliminating carbohydrates or whole grains (I'm looking at you, keto and Whole30), the importance of fiber for overall health and digestion is often overlooked. 

It's better to choose certain carbs over others. For example, swap out white bread, white rice, and white pasta for their whole grain alternatives. Not only will you get more fiber, but you will also be adding a variety of B vitamins and minerals to your diet. 

Food packaging can sometimes be misleading (e.g., multigrain vs. whole grain), so always check the ingredient list to make sure the word "whole" is listed before the grain. 

Q: Can we get fiber through drinks?

EDS: Smoothies are an excellent and convenient way to get some extra fiber in your diet. You can include bananas, berries, coconut, spinach, kale, or nut butters (the crunchy kind). 

To make sure you get all the benefits from the fiber of these fruits and vegetables, opt for blending them into a smoothie over juicing them, which removes the fiber. 

Over-the-counter fiber supplements in powder form are also available. These supplements can be mixed with liquids or with soft foods like yogurt. While sources of fiber from real food are preferred, these supplements can be helpful for people who struggle to get enough fiber from their diet.

These fiber supplements can interact with certain drugs, so always check with your doctor before starting them.

In Cedars-Sinai Magazine: Tummy Trouble Tips

Q: What does a lack of fiber do to our body?

EDS: Fiber is a type of carbohydrate that the body can't break down and absorb, and there are 2 types of fiber found in food: soluble and insoluble. 

Soluble fiber dissolves in water and forms a gel during digestion, which can slow the digestive system. This can make you feel full for longer, which can help with weight management. Soluble fiber can also help regulate blood sugar and cholesterol levels by slowing down their absorption into the blood. 

A diet rich in soluble fiber also promotes gut health and immunity. Fiber can improve absorption of water and electrolytes, regulate immune function, fight inflammation, and even help suppress tumor growth in the colon. 

Insoluble fiber does not dissolve in water and adds bulk to the stool, which can help keep bowel movements regular and prevent constipation

An adequate fiber intake is associated with reduced risk for heart disease, stroke, hypertension, some gastrointestinal diseases, obesity, type 2 diabetes, and certain cancers.