The hormone
Insulin has big impacts on the body's metabolism and many other bodily functions. Its mission is to cause muscles, fat tissue and the liver to absorb
glucose for use as energy to power the body.
When the body doesn't produce enough insulin, this metabolic function fails, which starves body cells of energy. The body then must use fat as an energy source (usually by breaking down lipids from
fat (adipose) tissue by the liver. When insulin production fails,
diabetes results.