Dietary Fiber: How Much Is Too Much?


Conventional wisdom tells us to “eat more fiber and drink more water,” and that is good advice, especially  for those eating too many refined carbohydrates. However too much of a good thing, too quickly, can cause unintended consequences. Here are some symptoms that can result from the consumption of too much dietary fiber, too quickly:

  1. Feeling bloated or over-full
  2. Excessive gas, flatulence
  3. Constipation or diarrhea
  4. Abdominal pain or discomfort
  5. Aggravation of Inflammatory conditions like Irritable Bowel Disease, Crohn’s Disease, Diverticulitis, or SIBO (small intestine bacterial overgrowth), hemorrhoids
  6. Mal-absorption of minerals and vitamins
  7. A rare and dangerous bowel obstruction
The daily recommended intake of fiber can vary from person to person,  but a good rule of thumb can be about 15 grams of fiber for every 1000 calories consumed. Other sources cite a range of 25 to 50 grams a day.  Usually a mix of soluble and insoluble fiber foods is recommended. Insoluble fiber is not digestible and is thus harder on the digestive system.  Soluble fiber has the benefit of feeding the beneficial microbes in our intestinal tract, along with fermented vegetables and dairy if tolerated.
I love vegetables, and have been steadily increasing my personal consumption of veggies over the last few decades. However, recently I have come to realize that reducing my dietary fiber has resulted in a happier digestive system. This was a counter-intuitive surprise for me,  so I recommend always testing out your own dietary changes slowly and carefully.  If you choose to increase fiber, do it slowly and be sure to increase your consumption of water, since fiber will also absorb water and can lead to dehydration in excess. If you regularly experience the symptoms in the list above, try reducing fiber and see if conditions improve. While supplementing with fiber such as Metamucil can help in the short term, a dependency on such supplements indicates a problem to discuss with your physician.
When reducing fiber, avoid the temptation to replace it with more refined or sweet carbohydrates. What is left to eat, you ask? Meat!  For personal accounts from people who have resolved serious health problems by severely limiting or entirely eliminating all fiber from their diet, see  (Scroll down to read the personal stories).
For further research, you can find the following book in your local library or in Amazon: Fiber Menace: The Truth About The Leading Role of Fiber in Diet Failure, Constipation, Hemorrhoids, Irritable Bowel Syndrome, Ulcerative Colitis, Crohn’s Disease and Colon Cancer by Konstantin Monastyrsky.

--Andrea Winchester