Math Doesn’t Always Add Up When Counting Carbs on Labels

The popularity of low carb diets such as Atkins, South Beach, and Paleo over the last decade have made many consumers aware of the importance of daily carbohydrate intake. Carb-restricted dieters count carbs as a way of life and for some diabetics, knowing the carb load of the food that they eat is critical for proper insulin management.

Unfortunately, searching for low carb foods in the aisles of your local supermarket is not as straightforward as you would think, as TINA.org reader Rose W. and her diabetic husband found out when reading the packaging for the Atkins Endulge Peanut Butter Cups.

The front of the box states that the treat is “Only 2g Net Carbs.” The nutrition label on the back, however, tells a different story: the total carbohydrates for a single serving (two peanut butter cups) is actually 18 grams, which is comprised of 5 grams of fiber and 11 grams of sugar alcohol.

Important facts are on the back

So where does the 2g of “net carbs” come from exactly?  Turns out that Atkins is using made-up industry terminology and doing a little tricky math.

You may be surprised to know that the term “net carbs” that is frequently displayed on the front of food packaging doesn’t actually have a legal definition and isn’t regulated by the FDA.  When it comes to carbohydrate claims, the FDA only regulates what is on the nutrition facts label on the back of food products.  That said, studies show consumers often rely most on what is on the front of the package label and give more meaning to low-carbohydrate claims than they should.

Because of this, the American Diabetes Association and others have given consumers some guidance on how to make sense of the often seen “net carbs” terminology.

Tricky Math

When counting carbs, fiber is traditionally subtracted from the total carbs since it generally passes through the body without being fully absorbed (or not absorbed at all in the case of insoluble fiber).  For people on intensive insulin management or “advanced carbohydrate counters,” the American Diabetes Association recommends subtracting only half of the total grams of dietary fiber when the amount is over 5 grams per serving.  Grams of insoluble fiber can be subtracted completely.

Like fiber, sugar alcohols are also not fully metabolized by our bodies.  They are added to products to provide a sweet taste with fewer calories. Sugar alcohols, however, are not carb free and the percentage of absorption (and therefore the effect on blood sugar levels) depends on the particular sugar alcohol used.  A generally accepted rule of thumb for counting sugar alcohols is to subtract half the total grams of sugar alcohols from the total carbohydrate count if they are greater than 5 grams.

So how did the Atkins Peanut Butter Cups do the math on its packaging?  Apparently, the “2 g of net carbs” comes from subtracting ALL the dietary fiber and ALL the sugar alcohols from the total carbohydrate count, leaving  just “other” carbohydrates that are not required to be listed. This is misleading and potentially dangerous for diabetics who are trying to carefully match their carbohydrate intake to their insulin dosage.  For Atkins to give its consumers a more accurate statement about its “net carbs,” the front of its packaging would say “7.5 g of net carbs” instead of “2 g of net carbs.”  That’s a big difference.

So our advice to consumers, and especially to diabetics, is don’t judge the product by what’s on the front of the package.  Flip it around and take a look at the nutrition facts label.

UPDATED 4/30/13: TINA.org reached out to Atkins and received a response from Colette Heimowitz, VP of Nutrition and Education at Atkins.  She agreed “with the basic theme of your article regarding the importance of accurate nutritional labeling for all food products,” but maintains that “while Atkins’ subtraction approach to determining net carbs is similar to the approach taken by The American Diabetic Association, the important distinction is that Atkins’ products are not marketed to diabetics or to manage a disease condition, such as diabetes.”