July 28, 2009

How Much Fiber Do You Need per Day?

How much of a good thing is a good thing? For all of the talk about how great fiber appears to be, no one seems to be able to agree on how much we really need. You can’t measure the amount of fiber in your blood or colon because you don’t absorb fiber – so, determining adequacy levels gets a little tricky.

What We Need

US Dietary Guidelines

The 2005 US Dietary Guidelines for Carbohydrates recommend that adults eat 14 grams of dietary fiber for every 1,000 calories. Since a good ballpark for most adults is 2,000 calories per day to maintain a healthy body weight, this works out to no less than 28 grams of dietary fiber per day.

Institutes of Medicine

The Dietary Reference Intake (DRI) committee is a group of nutrition experts who set recommendation levels for healthy Americans and Canadians. The DRI committee does not have enough data to set an Estimated Average Requirement (EAR) level for dietary fiber, which means it can’t confidently develop a Recommended Dietary Allowance (RDA) level either. As such, we have to settle for the less scientifically derived upon Adequate Intake (AI) level. The AI for fiber is based on median fiber intake levels that help achieve low risk for developing heart disease and the IOM recommendations are gender-specific:

Female Daily Fiber Recommendations:
  • Age 50 & younger: 25 grams per day
  • Age 51 & older: 21 grams per day

Male Daily Fiber Recommendations:
  • Age 50 & younger: 38 grams per day
  • Age 51 & older: 30 grams per day

What We Get

Regardless of whose recommendations you follow, one thing is certain: Americans are not getting enough fiber. Usual intakes in the US average about 15 grams per day1. Essentially, we are getting only half of the amount of dietary fiber that most scientific groups recommend!


1.) Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes: Energy, Carbohydrates, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. Washington, DC: National Academies Press; 2002