A large body of evidence now supports the benefits of fasting, though the most notable data has been recorded in studies with animals. Even so, these findings are promising for humans. Essentially, fasting cleanses our body of toxins and forces cells into processes that are not usually stimulated when a steady stream of fuel from food is always present. When we fast, the body does not have its usual access to glucose, forcing the cells to resort to other means and materials to produce energy.