With 1 to 2 grams of carbohydrate per stick, sugar-free gum in your low-carb diet should not cause you many worries. If you're chewing piece after piece, however, you may need to start paying attention -- not just for your low-carb diet but to prevent a bellyache, too.
What's in Sugar-Free Gum
Each brand of sugar-free gum has its own set of ingredients, but most contain a gum base plus a variety of sugar alcohols, including sorbitol, mannitol or malitol, and artificial flavors. Some brands also contain artificial sweeteners such as aspartame, sucralose or acesulfame. Soy lecithin, hydrogenated starch, carboxymethylcellulose and various other difficult to pronounce ingredients may also be present.
While-sugar-free gum contains a long list of various things, the sugar alcohols are the source of carbs in the gum. One stick or piece contains 5 calories or less, 1 to 2 grams of total carbs and zero sugar, fat and protein.
Sugar Alcohol Isn't Carb-Free
Unlike artificial sweeteners such as aspartame, sugar alcohols aren't calorie-free. A type of carbohydrate, sugar alcohols taste sweet like sugar, but the body only absorbs about half, reducing the number of calories and carbs your body gets. This also lowers the effect it has on blood sugar. In terms of numbers, your body absorbs only 1 of the 2 grams of carbs from your stick of sugar-free gum.
Be careful how much you chew, however. Too much sugar alcohol has a laxative effect that may cause abdominal pain and diarrhea.
Using Net Carbs
Some popular low-carb diets consider sugar alcohols a "free" food. These diets use "net" carbs to estimate total carb content of foods that contain sugar alcohol. Like fiber, sugar alcohol doesn't affect blood sugar, so subtracting the grams of sugar alcohol from the grams of total carbohydrate determines net carbs. For example, if a sugar-free stick of gum has 2 grams of total carbs and 2 grams of sugar alcohols, the net carbs would be equal to zero.
However, the net carb equation isn't as accurate as it sounds, according to a 2010 article published in Diabetes Forecast. To correctly estimate net carbs using sugar alcohol, count half the amount, or 1 gram of sugar alcohol if the gum contains 2 grams. So, that stick of gum with 2 grams of total carbs and 2 grams of sugar alcohol would have a net carb of 1 gram.
How Much Can You Chew?
Whether you count the carbs in your sugar-free gum may depend on the low-carb diet you're following. And while it may not be a big deal if you chew one piece a day, if you have a pack-a-day habit, you may need to start counting. For example, if you're limited to 20 grams a day on your low-carb diet and you chew 15 pieces of gum with 2 grams of carbs each, throughout the course of the day that's 30 grams of total carbs and 30 grams of sugar alcohol, or 15 grams of total carbs absorbed. That's nearly your entire day's worth of carbs. Plus, consuming an excessive amount of sugar alcohol, ranging from 20 to 50 grams a day, may lead to bloating and diarrhea.