Fiber is a special type of carbohydrate the body can’t digest. The 2010 Dietary Guidelines for Americans recommends eating 25-35 grams of fiber a day, but most of us probably only get about half that amount. If it isn’t broken down for energy, why is there a concern about not getting enough? While it may not be used for fuel, fiber plays a role in helping other systems in the body run smoothly.

There are actually two kinds of fiber: soluble and insoluble. Soluble fiber has been shown to help lower cholesterol (especially the LDL or “bad” cholesterol). When mixed with water, it dissolves into a gel-like substance that binds bile acid and interferes with the absorption of dietary cholesterol.  Good sources of soluble fiber include beans, oats, and fruit such as apples. Insoluble fiber (which does not dissolve in water) helps with moving food through the digestive system and removing waste. Whole grains and vegetables are good sources of insoluble fiber.

In addition to supporting heart and digestive health, fiber can also aid in losing and/or maintaining a healthy weight. Most high-fiber foods are naturally low in calories, but more importantly fiber promotes satiety: that feeling of being “full” after eating. Increasing the amount of fiber in your meals can help you feel full faster and keep that full feeling longer. And, since fiber causes food to move through the stomach more slowly, it can help keep blood sugars steady after meals.

A Registered Dietitian can work with you to find ways to increase your fiber intake, but a good place to start is eating plenty of fruits and veggies, whole grains, and beans. Replacing refined and processed grains with whole grains, or eating a piece of fruit instead drinking fruit juice (unless treating a low) are other things to consider. One final note: it’s best to increase your fiber intake gradually and drink plenty of water. Each week, add 5 grams of fiber to your daily intake until your intake is between 25-35 grams per day. Too much too soon can cause uncomfortable gas and bloating.

(Post content reviewed by MGH Department of Nutrition)