Net carbs, also know as the effective carb count, are the amount of carbs in a food minus the fiber and sugar alcohol. This is because your body does not digest sugar alcohol and fiber so they don’t count towards your carb total for the day.

For example, if you were eating something that has 10 grams carbs, 4 grams fiber and 2 grams sugar alcohol, you count the “net carbs” as 4 grams. Sugar alcohol is usually found in low carb sweets and desserts.

Fiber is a carbohydrate and is, at least in American nutritional breakdowns, included in the total carbohydrate count. However, fiber is a form of carbohydrate made of molecules so big that you can neither digest nor absorb them. Therefore fiber, despite being a carb will not push up your blood sugar and will not cause an insulin release. Even better, by slowing the absorption of the starches and sugars that occur with it, fiber actually lessens their bad influence.