September 2, 2010

The Truth About Fiber from Eat This Not That!

Men's Health Magazine's "Eat This Not That!" has became a wildly successful weight loss entity. It's a widely circulated email newsletter, magazine feature and now features a string of best selling books with titles like "Cook This Not That" and "Eat This, Not That! for Kids!"

Today's email newsletter topic is "The Truth About Fiber" where the authors pose nine "True or False" statements about fiber. The nine mini-articles give answers that are based on information and data largely supported by the general nutrition community. 

There is however, one rather controversial topic where the Eat This Not That! authors take a unique approach to answering a much asked question - and one covered in a previous blog post: "How much fiber do you need per day?"

The Dietary Reference Intake (DRI) Committee of the Institute of Medicine says males aged 50 and younger need 38 grams of dietary fiber per day (that's the highest of any age/gender group). But the Men's Health authors say that the 38 gram recommendation is bunk because it's based on three studies where the participants didn't even average as much as 38 grams per day. "In fact, people saw maximum benefits with a daily gram intake averaging from the high 20s to the low 30s."

It's important to point out that the DRI recommendation for fiber is what's called an "Adequate Intake" level, or AI recommendation. An AI is used when there's not enough data to set a "Recommended Dietary Allowance" level. RDAs are pretty solid and they are set when scientists are pretty certain that the amount of a nutrient they are recommending meets the needs of 98% of  people in that particular age and gender group. So, when there's not enough data for an RDA, they settle on AI, which is indicative of a lack of consensus, or really, a scientific shot in the dark.

Confusing? Yes. Bottom line: the average American eats only 14 grams of dietary fiber per day (Anderson et al., 2005). Regardless of whether you need fiber in the 20s, 30s or 38 grams per day - as a population, we're not eating enough. And despite the ubiquity of dietary fiber in our highly processed and packaged food environment, whole grains, fruits, vegetables and legumes remain the most simple sources of dietary fiber for all populations - no matter how much you need per day.