Study: Adding Fiber Can Be a Pain the Gut

By , SparkPeople Blogger
I'm a fan of fiber. In addition to keeping your GI system happy and healthy, fiber helps fill you up and ward off hunger--if Mother Nature put it in your food, that is. When fiber is added to processed foods by manufacturers, a new short-term study found that this functional fiber lacks the same hunger-busting benefits--and might even cause discomfort.
This "stealth" fiber is added to foods like granola and snack bars, breads, crackers, cereals, and even yogurt in the past few years. Inulin, polydextrose and maltodextrin are among the added fibers used by food manufacturers to add health benefits to foods.
Back in 2010 I wrote about the adverse reactions I have with inulin, so I avoid it and other forms of functional fiber to prevent bellyaches and bloating. The women in the study, who were given four snack bars with no added fiber and one with extra fiber, had the same reactions. When they consumed a high-fiber bar, they felt no difference in hunger levels versus when they ate the low-fiber bar, but they did report more gas and bloating.

I understand the appeal of added fiber foods. But if you're eating a well-balanced diet with plenty of whole grains, fruits, and vegetables, consuming the recommended 25-35 grams of fiber daily is within reach.

Let's look at a sample meal plan to see how fiber adds up:

  Fiber (grams)
1/2 cup oats cooked with water 3  
361 calories
1 cup soy milk 1
1/2 large banana, sliced 2
1 tablespoon chopped walnuts less than 1 gram*
Total 6
  Fiber (grams)  
328 calories
1 slice whole-wheat bread 2
1/2 ounce hummus 1
3 cups spinach 2
1/2 cup grated carrots 2
3 ounces cooked chicken breast 0
1 tablespoon ginger vinaigrette 0
Total 7
  Fiber (grams)  
157 calories
1 small apple 3
1 tablespoon chunky peanut butter 1
Total 4
541 calories
  Fiber (grams)
3 ounces extra lean beef 0
1 cup cooked brown rice 4
1 cup stir-fry veggies 4
1 cup skim milk 0
Total 8
Snack 2    
  Fiber (grams)  
1/2 serving reduced-fat whole-wheat crackers 2  
1 ounce low-fat Cheddar cheese 0  
Total 2 109 calories
Daily totals 27 g fiber 1,496 calories
Looking for ways to naturally increase fiber intake?

Do you consume functional fiber, or do you prefer it to occur naturally in your food?
*Walnuts do contain fiber, as a reader noticed, but in one tablespoon there is only a scant amount.

Has eating functional fiber ever led to unpleasant side effects?

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ALUKOWSKY 6/8/2017
I never have any trouble getting sufficient fiber since I eat lots of vegetables, fruit, and grains. I also never have any trouble with added fiber in processed foods, such as meal replacement bars. Report
SPUNOUTMOM 5/25/2017
I have tried to avoid added fibre in food, and try to keep fibre to natural sources. Whole grains, vegetables and fruit. Report
Oatmeal, either hot, steel cut, or Quaker oat squares with some berries on top-steady as she goes. Try steel cut oats for supper w/ grated cheese and a poached egg-comfort food and filling. Report
When I meet all my other nutrition guidelines, I manage to get the right amount of fiber, too. My GI track is much more regular and comfortable since tracking here. The fiber increase needed to be paired with staying well hydrated for the most comfort. I avoid added fiber - it hasn't been necessary. Lots of whole grains and fruits and veggies has meet my needs. Report
Two months ago, I took the Fiber Challenge here at SP. I went up to about 30 g of fiber daily. I ended up with a mild (even though it hurt like h*ll) case of Diverticulitis. Hospitalized for almost a week, I was placed on a low-fiber / low-residue diet. Too much fiber is not good for you. I'm back to about 16 g a day and I'm doing much better. Report
Yes, it can! I tried a Fiber Bar at work once and the cramps were so bad I nearly had to leave. Thinking it was a fluke, I tried them another time...thought I'd die from the intense pain so "no, thank you". Report
Fiber of any kind causes me discomfort. I have no trouble getting the daily recommended amount, and have to try not to go over, or I will pay for it. I particularly avoid insoluble fiber. Report
I have found when I try to eat added fiber food (ex: Fiber one and things like Skinny Cow) that I end up bloated and actually going less. Fruits and veggies have been the way to go (no pun intended) for me. Report
Good to know now what might be causing my daily bloating! Report
Interesting article but it's really hard for me to hit the daily amount even if I'm eating fresh veggies and fruits. I rely upon high fiber wraps and tortillas instead of bread. I'm leery of high fiber bars because of "adverse" reaction I had after about a month of eating them one/day. Fiber One bars are called "Farty One" bars around my house. Report
There is always some so called expert, who will come along and tell us how bad something is. Only to find out years later, it wasn't really bad at all. Hello, EGGS!
The most important thing is to listen to your body. If you can't tolerate it, don't eat it.
I have a Kellogg's Fiber Plus bar every morning. It's number one ingredient is chicory root, which naturally contains inulin. It also has iron, Vit. E & zinc. It is yummy & I have no intestinal problems eating it.
Again, listen to your body, if inulin/chicory root upsets you, don't eat it. If you are allergic to peanuts, don't eat them. We are all different, a one size fits all menu is not going to work.
Do some research, make an educated decision. See how your body reacts to a gradual increase in fiber.
FYI, right on the label it states: "NEW USERS: Increase your fiber intake gradually. Gastrointestinal discomfort may occur until your body adjusts."
I add ground flax seed to my lunch every day. Otherwise I wouldn't be getting enough daily fiber. Report
I have become a big fan of beans (especially chickpeas) and use them in salads, soups, mains dishes, and even baking. Low fat and lots of fiber. Yum! I have used Fiber One bars on occasion without a problem. Report
I get most of my fiber from fruits, vegetables, beans and whole wheat products. I do enjoy a low fiber bar but don't count on them to make up my fiber. Report
I can occasionally consume inulin without issue, but when it's a regular part of my diet, I get upset stomachs. My son hates it and it makes him bloat and ache (he's 5 and sometimes getting enough fiber in can be a challenge so we've tried it for him). If I need a boost, I use psyllium fiber instead, no problems with bloating, it's cheap and not all that bad tasting. (If I mix it with tea, it tastes like the Russian Friendship Tea my mom used to make with tang, instant lipton and powdered lemonade.) Report
Definitely have to add it slow!! Report
I get more stomach issues and bloat from too much protein Report
For a long time, it has been known that when you want to increase the fiber in your diet, you should do it gradually. In fact, it is my understanding that a lot of the intestinal woes of today's people are caused by a long term diet of insufficient fiber. The problem comes when people increase the amount fast and drastically. Report
My husband ended up in the hospital with an intestinal blockage from over-doing the "functional" fiber. After a year of experimenting with all types of no or low fiber diets, he is healthy & fit eating real food--lots of vegetables, a little meat, fruit & grain. I believe our bodies revolt when we try to trick it with "edible food-like substances." Report
Personally, I seem to have a problem with chicory root fiber, which is used in some of the fiber bars, causing discomfort. Report
I found that eating natural fiber gradually, you can have your 25g daily. I depend on Fiber One bars, milk, oatmeal & fresh fruit. Report
I don't understand why people would choose to eat fake fibre. Real fibre is so easily available. If a person has a gut issue which requires a higher than normal intake, then there are plenty of natural sources that can be incorporated into meals. Report
I have used benefiber for years without upset. I eat fiber one bars too and they fill me up for 145 calories. Report
My favorite fiber rich food is Kellog's All Bran. 10 grams per one half cup serving. Report
good Report
Walnuts do have fiber, but not even a gram in such a small amount. Report
I would question the data used above that walnuts don't have any fibre?? According to my research, they do contain insoluble fibre and traces of soluble fibre. Report
My doctor told me I have a "lazy" gut. He instructed my to take the supplements. Not the ones with cyllium (there is more gastric distress). I use benefiber, and it works for me. However, there are times I take it only once, rather than twice daily. Report
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