Fiber does plenty of good things in your body, but its place in caloric calculations has yet to be nailed down. Get some soluble knowledge about this important dietary component! Fiber can be a little confusing.
For a while, nutritional labels split this category into “soluble” and “insoluble” fiber, but those definitions didn’t capture the function the fiber served. So the USDA’s newer fiber definitions got rid of those classifications, opting instead for “dietary fiber” and “functional fiber.” These two are defined by the USDA’s Dietary Reference Intakes as:
Dietary Fiber: non-digestible carbohydrates and lignin that are intrinsic and intact in plants
Functional Fiber: isolated, non-digestible carbohydrates that have beneficial physiological effects in humans