The RP Diet app counts carbs as total carbohydrates minus fiber.
For example, if a nutrition label displays 20 grams of total carbohydrates, of which 15 are dietary fiber, the app will display the food as containing 5 grams of carbs. Sugar alcohols are counted.
Though many food manufacturers exclude sugar alcohols from their reported "Net Carbs" values, the app counts sugar alcohols as carbohydrates. Though some sugar alcohols have very few calories, many commonly used sugar alcohols have a considerable calorie load, and are thus treated in our data as equivalent to other carbohydrates.
Fiber consumption promotes both health and satiety(Check out this in-depth article), while sugar alcohol consumption is at best neutral for health and can cause considerable gastric upset in even moderate quantities. Thus, our treatment of the data encourages more fiber consumption, and moderates sugar alcohol consumption, which is likely a net benefit for the vast majority of dieters.
Please check out the following two examples.