Fiber, Fiber, Everywhere… But Is It All The Same?

| Posted On Nov 13, 2013 | By:

fiber is good for controlling cholesterolWe all know it’s good to eat more fiber.  Unfortunately, most Americans don’t get anywhere near the recommended 30 grams of fiber each day.  In fact, the average intake is only around 10-15 grams per day for most of us.  To help inch us closer to our goal, food manufacturers have started adding fiber to anything and everything.  It’s now in yogurt, cottage cheese, breakfast bars, and even some beverages, and of course, it’s long been in fiber supplements like Metamucil or Benefiber. So does it matter where or what form your fiber is in? Or is all fiber the same?

What is fiber?

Fiber, also known as roughage, is the part of plant food that is not digestible.  Therefore, it passes through our GI tract rather than getting absorbed by our body.  There are two types of naturally occurring fiber, and both types are in all plant foods in varying amounts. Soluble fiber absorbs water and forms a gel inside our GI tract.  It tends to slow down our digestive process a bit which helps to keep us feeling full longer.  Soluble fiber also helps to control blood sugar and it can reduce LDL (bad) cholesterol.   Insoluble fiber does not absorb water and has more of a laxative effect.  Fiber is naturally found in all plant foods like whole-wheat products, oats, beans, fruits and vegetables.

So what about the fiber in my cottage cheese?

In an effort to boost fiber in many popular foods that are not naturally good sources of fiber, manufacturers often add inulin.  It’s a tasteless starch that can either be derived from plants or made in a lab.  Because our bodies don’t have the enzymes to break down inulin, it’s not digestible, and can be classified as a fiber.  To find out if there is inulin in your “high fiber” food, many manufacturers list the information online, so check the ingredients label.  Inulin is also known as:

While inulin can have some health benefits, it’s not quite as beneficial as naturally occurring fiber. Inulin won’t help with weight loss, because it doesn’t make you feel full like naturally occurring fiber does. It also doesn’t help to manage blood sugar and has less of an effect on cholesterol.  From a nutritionist’s standpoint, the major gripe is that foods that are fiber-enhanced with inulin can carry health claims that are really misleading.  It really doesn’t matter how much “fiber” you add to that cookie, granola bar or juice, it’s still not a health food.

Another major drawback of foods with added fiber from inulin that many are not aware of is the potential for gas, bloating and stomach cramps. Inulin is a prebiotic, which means it functions as food for the healthy bacteria that live in our intestinal tract.  While prebiotics are good because they help our healthy bacteria to flourish, the downside is that, as the bacteria break down the inulin, lots of gas (CO2) is left behind.

The bottom line on fiber

You’ll get the most health benefits from naturally occurring fiber, so aim for about 30 grams each day by eating cereals with at least five grams of fiber per serving and bread with at least two grams of fiber per slice.  When eating grain products, skip the white rice and go for whole grains like quinoa or farro instead.  Aim for at least five servings of fruits and vegetables each day – each serving (one average piece or about ¾ cup cut up) has about five grams of fiber.

If you feel like you can’t eat enough of the above foods, or you still need a little extra fiber “to get things moving,” try a fiber supplement – most are not inulin based – but check the label. Many people are surprised to learn that each serving of a fiber supplement only contributes about three grams of dietary fiber.  I don’t know about you, but I think an apple or banana is more appealing.

Finally, eating foods with added fiber is certainly better than not eating any fiber at all.  If you use foods that are supplemented with added fiber from inulin, make sure you don’t overdo them, especially if you experience any severe GI discomfort a few hours after eating them.

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About Anne Danahy, MS, RD, LDN

Anne Danahy, MS, RD, LDN has been a Nutritionist with Harvard Vanguard Medical Associates for the past 15 years, and she currently works as the “Virtual Nutritionist." Her professional interests include weight management, heart disease, and women’s nutritional issues. When she isn’t working, you can usually find her in the kitchen testing recipes that are healthy AND delicious.


  1. Thank you for this helpful information on fiber.

    Comment by Doris on March 20, 2014 at 9:50 pm
  2. I enjoyed your article. I quite smoking about 9 months ago and since then have been trying to eat primarly organic foods, expecially fruits and vegatables. Can you recommend a good book on Nutrition? I am 67 and in excellent health, and take no medication. I have been usiong an app called MyFitnessPal and it recommends 23 grams of fiber. I am happy to see your recommendation as I have now found the right combination of foods that will give me about 33 grams of fiber per day.


    Comment by Terese Berg on April 6, 2014 at 8:54 am

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