What makes Fiberfit unique is its concentrated sweetness with fiber, but without calories. It is approximately 8 times sweeter than sugar. Sucralose by itself is generally accepted to be 600 times sweeter than sugar.
Some "no calorie" sweeteners achieve a 1-to-1 ratio to the sweetness of sugar by blending sucralose with maltodextrin and even dextrose and, in some cases, other sweeteners such as aspartame, acesulfame k, and sugar alcohols. Sucralose is so concentrated that a blend may contain less 1% sucralose. Fiberfit does not contain any other sweetening agent besides sucralose..
The US FDA allows such products 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, those products may declared as having 0 calories.
In applications such as cooking and baking, large amounts of sweeteners often are used and "0" calories instantly become lots of calories. The 8 calories on the Nutritional Facts represent calories from non-digestible fiber. That means Firberfit truly has no calories from carbohydrates.