What makes Fiberfit unique is its concentrated sweetness with dietary fiber, but without calories. It is approximately 8 times sweeter than sugar. Sucralose, the sweetening agent, by itself is generally accepted to be 600 times sweeter than sugar.
The US FDA allows products such as Splenda™ to be declared as having no calories because the amount of carbohyrdrates from ingredients like maltodextrin and dextrose per single serving is under 1 gram. So, such products may declared as having 0 calories.
Cooking and baking often require large amounts of sweeteners and "0" calories instantly become lots of calories. The 8 calories on the Nutritional Facts panel represent calories from non-digestible fiber. That means Fiberfit truly has no calories from carbohydrates.