Insoluble and Soluble Fiber: Dietary Needs

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Proteins & Amino Acids: Importance & Dietary Needs

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 Fiber in the Diet
  • 0:18 The Definition of Fiber
  • 2:02 Soluble Vs. Insoluble Fiber
  • 3:51 Benefits and Dietary Needs
  • 4:28 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode
Lesson Transcript
Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

If you didn't know this already, there are many different kinds and functions of fiber! You'll learn about what dietary, functional, total, soluble, and insoluble fiber is and how much you need each day and why.

Fiber in the Diet

Fiber. You've heard that it's good for you and that many people don't get enough fiber in their diet. But there's more than one kind of fiber, and fiber does more than just help move feces along the digestive tract, as you're about to learn.

The Definition of Fiber

Fiber is a non-digestible carbohydrate naturally found in plants. A carbohydrate is a sugar. But unlike table sugar, fiber is made up of many little units of sugar linked together into chains and knots that cannot be unraveled, or digested, by our body. If it cannot be digested, then it can't be used for energy.

You can imagine how if you had a piece of string with one knot it in, the string could easily be unraveled, or digested by our body, and then used for another purpose. That's table sugar for you. But if that same piece of string had hundreds of knots and was tied in a very difficult way, just like fiber is, it may be impossible to untie everything. That's what fiber is when compared to a simple sugar.

Furthermore, there are two divisions of fiber. There is dietary fiber, which is fiber that is found naturally in grains, fruits, vegetables, and legumes, and then there's functional fiber, which is fiber that is made in a lab or extracted and isolated from natural sources and added to a dietary supplement or food thereafter. The sum of dietary and functional fiber is known as total fiber.

Basically, if you get your fiber from oatmeal, that's dietary fiber. If you get it from a dietary shake that has added fiber, then that's functional fiber.

To help remember the differences between the two, just look at the names themselves. Dietary literally implies it comes from your diet, a natural diet. If it's functional, then remember it serves to add the function of fiber to food that doesn't naturally have enough fiber within it.

Soluble vs. Insoluble Fiber

Now, I did say in the beginning there are different kinds of fiber. It's not just about dietary vs. functional fiber. There are other divisions involved and things each kind of fiber can do.

There is something called soluble fiber. This is a type of fiber that reduces the absorption of cholesterol, decreases the movement of glucose into the blood after a meal, and delays stomach emptying.

Soluble fiber turns into a gel when mixed with water in your gastrointestinal tract. Because soluble fiber delays stomach emptying, it makes you feel fuller and thus makes you less prone to overeating. This obviously helps to control a person's weight.

Additionally, because soluble fiber delays the amount of time glucose (sugar) moves into your bloodstream, it helps to prevent massive sugar spikes in your body that lead to energy crashes thereafter.

Sources of soluble fiber include oatmeal, nuts, seeds, and lentils.

On the flipside is something called insoluble fiber. This is a type of fiber that helps to add bulk to a stool, pass stool more quickly, and thereby prevent things such as hemorrhoids, constipation, and more. Insoluble fiber can be found in wheat bran, vegetables, and whole grains.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account