Benefits of eating fiber

Originally Published: May 15, 1998 - Last Updated / Reviewed On: May 30, 2014
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Alice,

What are the benefits of eating fiber? How can too much fiber in one’s diet be dangerous?

Dear Reader,

As they say, everything in moderation — including fiber! Eating enough fiber can have many health benefits, while too much may have consequences. By learning how much fiber you need, how much is in your food, and adjusting your diet accordingly, you’ll be able to strike a balance that’s ideal for your body (and your bowels). 

Fiber is basically composed of plant-based food matter (fruits, veggies, whole grains, and legumes) that can’t be broken down by your digestive system. Whole foods contain both soluble (dissolves in water) and insoluble (does not dissolve in water) fiber. Although the recommendations below don’t distinguish between these two types of fiber, they are different and have distinct functions — soluble fiber helps to reduce cholesterol and glucose levels, and insoluble fiber helps with constipation by increasing fecal bulk. 

Overall, fiber may lead to many health benefits, such as:

  • Keeping you regular. Fiber decreases the risk of constipation by bulking up and softening your stool.
  • Maintaining your bowel health. Fiber may prevent the development of diverticulitis and hemorrhoids. It has also been shown to reduce the symptoms of irritable bowel syndrome (IBS) in some cases.
  • Lowering cholesterol and blood glucose levels. By reducing bad (LDL) cholesterol and blood glucose levels, soluble fiber also leads to a decreased risk for cardiovascular disease, coronary heart disease, and type II diabetes.
  • Controlling your appetite/weight. Foods that contain fiber are typically low in fat, energy-dense, take more time to chew, keep you full for longer, and block some of the digestion of fats and proteins.
  • Preventing cancer. Fiber consumption may lower the risk for colorectal cancer, but the evidence is not yet conclusive.

Curious if you are getting enough fiber in your diet? You can use either the USDA Food List or WebMD’s Fiber-o-Meter to figure out the fiber content of the foods you eat and get suggestions for high-fiber foods. Making a habit out of reading the nutrition facts on food labels will also help. Generally, women need less fiber than men, and those aged 51 years or older need less than younger individuals. The following table can give you an idea of how much fiber you need on a daily basis:

 

Age 50 or younger

Age 51 or older

Men

38 grams

30 grams

Women

25 grams

21 grams

Source: Institute of Medicine

However, having too much fiber in one's diet can cause problems. When the intake of fiber is too high, it can replace other energy and nutrients that you need in your diet. Some insoluble fibers bind certain minerals, including calcium, magnesium, phosphorous, and iron. Too much fiber can also cause abdominal discomfort, gas, and diarrhea, and block the gastrointestinal (GI) tract if you add too much fiber too fast. For some, fiber supplements may potentially cause additional, more severe side effects such as allergic reactions and asthma, gastrointestinal distress, and drug and nutrient interactions. If you feel that you might benefit from taking fiber supplements, it's best to speak with a health care provider first to make sure it’s right for you.

So, before you load up on fiber, try adding it to your diet gradually, so that your GI tract has time to adapt. You'll also want to drink lots of fluids to keep the fiber soft. Choosing a variety of soluble and insoluble fiber-rich food sources, such as fruits, vegetables, whole grain breads and cereals, and legumes (beans and peas) will ensure that not only will you get a good mix of fiber, but beneficial nutrients, too. Remember that brown rice and 100 percent whole wheat bread have more fiber than white rice or white bread. Also, eating the skins of your fruits and vegetables whenever possible can also help increase fiber intake. If you're a Columbia student and need advice or more information about incorporating fiber-rich foods into a balanced diet, you can make an appointment with a health care provider or a registered dietitian by contacting Medical Services (Morningside) or the Student Health Service (CUMC).

Hope this was helpful!

Alice