Insulin is a storage hormone. Under high insulin levels (mealtimes), the body stores energy in the form of glycogen and fat. Cortisol, however, prepares the body for action, moving energy out of stores and into readily available forms, such as glucose. That cortisol and insulin would have similar weight-gain effects seems remarkable—but they do. With short-term physical stress, insulin and cortisol play opposite roles. Something quite different happens, though, when we’re under longterm psychological stress.
