September 24, 2013

How to Choose "Best Carbohydrate Quality"? The 10-to-1 Rule

A recent Harvard study offers a nifty way to decide whether or not a product meets a real “whole grain” standard: the 10-to-1 rule. As shown on the product’s nutrition facts panel, the ratio of TOTAL CARBOHYDRATES to FIBER should be LESS THAN ten to one.

Here’s the easiest way to do the math: multiply the grams of fiber by ten. That total should be GREATER THAN the carb grams.

Why 10-to-1? That’s the ratio of carbs to fiber in whole wheat flour.

It’s a good sign if an item on your grocery store shelf is labeled “100% whole wheat” or “100% whole grain.” Also look for the voluntary “Whole Grain Stamp” issued by the Whole Grains Council (which the Berkeley Wellness article rightly indicates is supported by dues from industry members). That stamp guarantess at least eight grams of fiber per serving. Here are two examples of those stamps from the WGC:

These days, grains are regularly stripped of their nutrition-packed bran and germ, a process that creates carbohydrate-heavy food.

That germ-stripping process is a key culprit – just one example here – in the diabetes epidemic in Nepal. For centuries there, people were happy to eat the hearty brown and reddish rices that packed loads of nutrition. But in recent years, Nepalis have become enamored of lovely “polished” white rice. This product puts a hefty dose of carbohydrates (minus the fiber and proteins that have been removed for cosmetic purposes) into the stomach, creating sharp insulin spikes in the blood stream. Repetition of that pattern through time has made diabetes a major healthcare issue in my beloved Nepal. Of course, the more sedentary lifestyle there -- fewer people living, working, farming in the country; more sitting at desks or in front of TVs in cities -- also contributes to the health crisis in Nepal.

In many grain-based foods – pastas, breads, cereals -- the “whole grain” appears way down the list of ingredients, often after added sugars and “wheat flour,” a misleading term which really means “white,” “refined,” or “enriched” flour. This stripped-down flour is another insulin-spiking culprit in the diabetes war.

Published in Public Health Nutrition, the Harvard study considered 545 grain products and evaluated the helpfulness of several available assessment guidelines:
  • the new 10-to-1 ratio,
  • the Whole Grain Stamp, and
  • three general USDA guidelines for whole grains.
The careful review determined that the ratio was the “best single metric” to “capture overall carbohydrate quality.” The ratio also eliminates the need to search ingredient lists for different types of whole grains (29 plus) and added sugars (more than 21 kinds).

As the Berkeley Wellness story points out, this ratio guideline isn’t perfect. For example, several perfectly healthful whole grains – wild rice, cornmeal, brown rice – have a bit less fiber than whole wheat, the ratio standard. As a result, they don’t make the 10-to-1 cut.

There’s another issue the ratio doesn’t address: the addition by manufacturers of “isolated” fibers, like inulin from chicory root. Companies can make these additions in order to claim high-fiber content.

Still, this ratio seems helpful and is certainly easy to use. I’ll keep it in mind.

Here are just two examples from my larder (I’m not even sure how these things got into my kitchen!):
  • San Giorgio spaghetti – per serving, 42g carbs, 2g dietary fiber. That’s an insulin-spiking ratio of 21-to-1!
  • Barilla whole grain pasta – 41g carbs, 6g fiber. That’s less than 7-to-1… MUCH better.

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