Susan was just diagnosed with diabetes. Doug is looking to lose 20 pounds. Both decide to try to cut back on carbs to help with weight loss and blood sugar control. They start buying low-carb food items, focusing on those that have the least "net" or "impact" carbs per serving. Will these products really help, or is it just another marketing scam?

The American Diabetes Association first introduced "carbohydrate counting" as a way to control blood sugars in people with diabetes. Compared to protein and fat, carbs have the most impact on blood glucose, so they must be monitored carefully.

Fiber in foods is not digested and absorbed like other carbohydrates. Our bodies do not convert it into blood glucose. Sugar alcohols also have little impact on blood sugars and are lower in calories than regular sugar. Manufacturers can add these ingredients to their products to create lower-calorie, lower-carb foods.

Hence, the creation of "net carbs." Food manufacturers add the total carbohydrates in a product and subtract the grams from fiber and/or sugar alcohols. What is left over are the net carbs - the only ones (so we are told) we need to "count" toward our total intake.

A misleading label
The main concern with the new "net carb" label is the subtraction process. It includes all fiber grams and all sugar alcohols.

• Some sugar alcohols can cause blood sugar to rise. If you have diabetes, test your blood sugar after you eat an item with sugar alcohol. If it makes your blood sugar rise, you will need to read labels carefully to see which type of sugar alcohols are being used. Ingredients to look for include mannitol, maltitol, sorbitol, xylitol and other polyols.
• Sugar alcohols do have calories! Many people assume that a product with a small amount of net carbs can be considered a "free" food. This is far from the truth. Many of these products are highly processed and still have a fair number of calories. Over time this can contribute to weight gain. For example, a popular protein bar with 2 grams of carbs also has 260 calories. This must be counted toward the daily calorie intake, carb or no carb.
• Many sugar alcohols cause digestive problems. Foods with 10 or more grams of sugar alcohols may cause intestinal gas, bloating and diarrhea.
• Added functional fiber. Manufacturers will often add "functional fiber" to nutritionally depleted foods. Consumers may be getting more fiber, but not from a whole food source (vegetables, fruits, whole grains, beans/legumes). Whole foods offer many more vitamins, minerals and antioxidants. Telltale ingredients include maltodextrin, polydextrose, inulin, guar, xanthan and cellulose.

The bottom line
Many of the foods being marketed as low-carb are overly processed and nutritionally depleted. The healthiest meal plan for weight loss and blood sugar control is a nutritious diet of whole foods. Small amounts of low-carb food products may be okay, but not at the expense of eliminating vegetables, fruits, beans and whole grains. Nothing can really replace the goodness of natural foods.

Related Articles How to Get More Fiber in Your Diet Want to Lose Weight? Eat Some Carbs How to Rev Up Your Metabolism

External Sources American Dietetic Association. "Net-impact carbohydrates" - new term on food packages. . Accessed November 26, 2007 National Consumers League. Misleading "low carb" claims. . Accessed November 27, 2007