Do You Subtract Soluble and Insoluble Fiber When Getting Net Carbs?

Net carbohydrates are the carbohydrates that have an immediate blood glucose impact. Calculating net carbohydrates properly is important to understanding the foods you eat and how they affect your diet. When you are reducing the carbohydrates in your diet or taking medications such as insulin that are measured in relation to carbohydrates, net carbohydrates are an essential calculation.

The carbohydrates listed on a nutrition label include starch, sugar, dietary fiber and sugar alcohol. Starch and sugar break down into glucose, which your body's cells use for energy. Dietary fiber is not digested, so it creates no impact on your blood sugar. Sugar alcohol has minimal impact on blood sugar levels.

Insoluble fiber does not dissolve in water and is not absorbed by your body. Insoluble fiber helps to encourage regular bowel movements and moves waste through your body steadily. When your body passes insoluble fiber through without absorbing it, there is no impact on your blood glucose levels. Identify the amount of insoluble fiber in the food, typically listed under the carbohydrate figure. Subtract the amount of insoluble fiber from the carbohydrate count.

Soluble fiber creates a viscous solution when introduced to water. If the remaining fiber is more than 5 grams after subtracting the insoluble fiber, subtract half of the soluble fiber. For example, if there are 8 grams of soluble fiber, reduce the carbohydrate count by 4 grams. Do not subtract any of the soluble fiber if there are less than 5 grams.

To obtain an accurate net carbohydrate figure, identify any sugar alcohol content per serving. Sugar alcohol has a limited impact on blood glucose, so you only need to account for half of the sugar alcohol content in your net carbohydrates. For example, if there are 10 grams of sugar alcohol per serving, reduce the net carbohydrates by 5 grams.