Why Is Counting Net Carbs Important?
Low carb and ketogenic diets rely on the principle of lowering blood sugar to help you lose weight.
By reducing total carb intake, your body has less glucose to burn for energy. That means it has to use more body fat as fuel.
However, undigested carbs don’t raise blood sugar levels. So it’s only net carbs that need to be counted.
First off, there are two types of fiber called soluble and insoluble.
Insoluble fiber is not digested at all. Instead, it passes through your stomach and intestines intact. Therefore, it doesn’t contribute any calories.
Whereas soluble fiber dissolves and gets partially digested. Specifically, about 1/4 to 1/2 of the calories from soluble fiber get absorbed according to studies1,2.
While fiber may provide some calories, it doesn’t raise blood sugar. And that’s why fiber doesn’t count towards net carbs.
Another key aspect of net carbs is sugar alcohol. The food industry uses sugar alcohols to add sweetness with fewer calories than regular sugar.
The reason sugar alcohols have fewer calories is that our bodies can’t break them down properly. In fact, some types pass through you without being digested.
However, that doesn’t mean you can eat them to your heart’s content. Most sugar alcohols provide some calories. On average, about half as much as regular sugar.
Despite providing fewer calories, sugar alcohols can still raise blood sugar. Which is why half the amount of sugar alcohols count towards net carbs.
Here’s a list of the glycemic index and calorie content for common sugar alcohols compared to regular sugar:
The glycemic index quantifies how fast a carbohydrate breaks down into glucose. Where the higher the number, the more that food raises blood sugar.
With these numbers, you can see that sugar alcohol is slower digesting than regular sugar. And that means blood sugar stays lower.
At the end of the day, counting net carbs is a way to manage blood sugar levels and help you burn more fat.