There are two types of fiber: soluble and insoluble. Fruit and vegetable juice contains soluble fiber, which lowers cholesterol, controls blood sugar levels, and more. The pulp contains insoluble fiber, which simply adds bulk to your stool. A balanced diet contains both types of fiber, but juicing is a great way to absorb a large amount of soluble fiber without filling your stomach with insoluble fiber. Read more about soluble and insoluble fiber.