This appears in this month's issue of Outside Magazine. It seems to be a well-informed answer to an oft-asked question.

http://outside.away.com/outside/bod...s_20040406.html

What are "net carbs"?

Net carbs are mashed potatoes, creamed corn…basically anything served by a person wearing a hair net. Just kidding—for the growing phenomenon of the phrase "net carbs" on labels dotting your grocery store aisles, you can thank the teeming hordes currently on some form of low-carbohydrate diet.

The people at Atkins and elsewhere say that net carbs are the total number of carbohydrate grams in a "low carb" food product, minus the grams of those carbohydrates that cause little to no elevation in your blood-sugar level. The entire diet, you will recall, is based on the idea of releasing people from the cycle of blood-sugar spikes and an ensuing insulin-mediated storage of dietary carbohydrates as fat.

Because fiber is a carbohydrate that merely tips its hat at your lower intestine, they subtract grams of fiber from the total number of carbohydrate grams. Fair enough—even if you do have to search the prepared product aisles with bomb-sniffing dogs to find foods containing more than a scrap of fiber. Another carbohydrate form known as sugar alcohol (anything on the label ending in -tol or -ol) is also believed to cause only a minimal rise in blood sugar, so food makers exclude those from their net carb calculations as well. The carbohydrates polydextrose, and glycerin (an ingredient most commonly found in soap) are also excluded, for the same reason.

Critics of this new math say that all of the above are still carbs, and any carbs ingested in an environment of elevated blood sugar will be stored as fat whether or not those carbs were guilty of raising the blood sugar themselves.

The FDA is looking into the entire low-carb labeling question, including the net carbs claim. And the Center for Science in the Public Interest recently complained about "net carbs" labeling, portending a future where the nutrition facts label becomes "a zoo of competing numbers." Think of the entire debate as part of a vocabulary which makes us slaves to the food-approval issuances of a cardiologist-turned-branding giant. Consider that it has been used to sell the world a low-carb peanut butter cup.

I only subtract fiber. I count all other carbs.

I must admit, being new to all this, I tend not to subtract anything if possible, as I feel that I will accidentally be taking in more carbs than allowed if I start to make my own calculations as to what should be subtracted...then what a state I would be in...lol.

Michele

polydextrose is almost always listed as fiber now. I subtract glycerine just fine unless its lumped together with the SAs in which case I deduct 50% of SAs

I treat sugar alcohols as regular carbs. I figure they are 'empty' calories, the same as sugar; whether or not they raise blood sugar levels. There are no micronutrients in them and I figure I am better off using my carb allotment on food with better nutritional values.

I agree with Dodger.

Me too!

I subtract Fiber only.

I subtract 100% for Fiber, Polydextrose, Glycerine, Mannitol, and Erythritol. I count partial carbs for all other SAs and Tagatose, based mostly on their glycemic index and absorption rate. Some SAs, think Maltitol Derivatives are moderate to high glycemic and as much as 75% absorbed in some cases, and as such I count most, and in one case [Maltitol Syrup] ALL of the absorbable carbs [3 out of every 4 grams] in them. Isomalt and Lactitol are low glycemic and about half absorbed. But, more than 1 bar or so made with them, will send me straight to the bathroom for the rest of the night. So, I generally avoid those 2 as much as possible. I try to find stuff made with Erythritol [2% Absorbed; GI=0] as much as possible. I also like Tagatose [<38% Absorbed*; GI=3] also.

Here's the numbers I currently use. I count the listed percentage of the "Carbs" from that SA --



*Some studies have found even lower absorption rates for Tagatose.
*I count 48% of Glycerine as Total Fat. Glycerine/Glycerol is the backbone of most Lipids [Fats,] and is Non-Glycemic [doesn't affect blood sugar.] Since the Fatty Acid component, not the Glycerine component determines the subtype, I don't count Glycerine in any of the subtypes, only in the Total Fat count.
*I count 100% of Polydextrose as Dietary Fiber.