by Marion Nestle

Currently browsing posts about: Fiber

Nov 30 2016

FDA seeks input on issues related to dietary fiber

You might think that fiber simply refers to components of food plants that cannot be digested by human enzymes and are excreted in feces.

No such luck.

Like everything else in nutrition, fiber is complicated, not least because intestinal bacteria can digest some of those components and produce nutrients we can use.

In May, the FDA said that naturally occurring dietary fibers such as those found in fruits, vegetables and whole grains—and 7 specific isolated or synthetic fibers—could be declared on the label under “Dietary Fiber.”

The FDA defines fiber as (no, I’m not kidding):

non-digestible soluble and insoluble carbohydrates (with three or more monomeric units), and lignin that are intrinsic and intact in plants; isolated or synthetic non-digestible carbohydrates (with three or more monomeric units) determined by FDA to have physiological effects that are beneficial to human health.

The isolated or synthetic non-digestible carbohydrates said to have beneficial effects are:

  1. [beta]-glucan soluble fiber
  2. psyllium husk
  3. cellulose
  4. guar gum
  5. pectin
  6. locust bean gum
  7. hydroxypropyl methylcellulose


Cows and termites can digest cellulose.  We can’t.  But the FDA has evidence that they do other good things, for example, like lowering cholesterol.

The makers of processed foods love using these fiber additives for their various texturizing properties—and also because they can claim them as fiber on the label.

Now the FDA wants help in understanding whether 26 other kinds of isolated and synthetic fibers qualify as “Dietary Fiber” on food labels and, if so, what their beneficial effects on health might be.

The mind boggles.  This is another reason to stick with fruits, vegetables, and grains.

The comment period for the Request for Information opens on November 23, 2016 and will be open for 45 days.

For Additional Information:

Mar 27 2012

Nutritionist’s Notebook: Importance of fiber

This semester I answer students questions about nutrition on Tuesdays in the student-run Washington Square News.  Today’s is about fiber.

Question: We tweeted and linked to the article you were cited in The New York Times on Tuesday, and you mentioned the importance of fiber in a diet. How much fiber is good to have in a daily diet, and what does it do for our bodies? What are good sources of fiber — cereal bars, granola bars? How much is too much fiber?

Answer: You, like most Americans, probably get less than half the fiber you need. You can fix that by eating more vegetables, fruits, nuts, beans, peas and whole grain breads and cereals. Fiber occurs only in plants.

Eating these foods at every meal will do wonders for your digestive system. They help protect you against obesity, heart disease, Type 2 diabetes and even some cancers.

Fiber refers to a bunch of plant carbohydrates that human enzymes cannot digest easily. These come in two types: insoluble and soluble. Insoluble fiber, the kind found in grains, almost completely resists digestion. It has no calories.

But soluble fiber from beans and other vegetables can be digested to some extent by bacteria in your colon. They produce a little energy you can use.

Research shows that people who eat plenty of vegetables, fruits and whole grains with both kinds of fiber develop less chronic disease. But these benefits do not show up in studies using fiber supplements.

This means you are better off eating vegetables than power bars. If you must eat those bars, choose the ones with fruits, nuts and whole grain — real foods — high up on the ingredient list. Watch out for misleading claims about “good source of fiber.”  Check the Nutrition Facts panels — 3 grams is minimal, 5 is better.

If you are not used to eating fruits, vegetable and grains, eating more of them may make you feel gassy. Gradually include more. Your digestive system will be happier, and you will be healthier.

Dec 26 2008

Do whole grains do any good?

At the request (and expense) of Kellogg’s, the Life Science Research Organization convened an expert panel to evaluate studies linking consumption of whole grains – as defined by FDA – to reduced risk of cardiovascular disease and diabetes.  Using the FDA’s definition, the panel judged the studies insufficient to support a claim that whole grains reduce the risk of cardiovascular disease or diabetes.  The FDA defines whole grains as whole: grains that are ground, cracked, or flaked but include all the parts in their original proportions.  When the panel expanded the definition of whole grains to include supplements of bran, germ, or fiber, the results came out better.   Supplements work better than the real thing!  Kellogg’s must be pleased with the results of its investment.

Feb 4 2008

USDA reviews food industry progress on fiber

The USDA has now given us a poster child for the food industry’s good intentions in helping to improve the American diet.  The agency’s new fact sheet on dietary fiber documents how the food industry has used technology to add fiber and whole grains to processed foods.  Even so, the total amount of fiber and whole grains available in the food supply just doesn’t seem to budge.   Why not?  The USDA says the grain-based food industry isn’t giving the agency the data it needs to demonstrate increases and that “a collaborative working relationship” is needed to get better data.   Getting more data from the food industry–especially about food composition–would be nice but isn’t going to help people eat more fiber-rich foods.  For that, how about eating unprocessed foods!