Insulin

  Insulin is the hormone that allows blood sugar to be used by the cells. A side effect of insulin is that it causes fat to be deposited, and it stimulates the brain to produce hunger signals. 

The control of insulin by restricting the intake of carbohydrates puts a halt to the  cycle of hunger from insulin production. When carbohydrate intake is restricted, the insulin level decreases and the glucagon level increases. 

Glucagon is a hormone that causes body fat to be burned and cholesterol to be removed from the arteries.

If carbohydrates are severely restricted, the body goes into a state of ketosis, burning fat with the subsequent production of ketone bodies in the bloodstream.  As a result the blood sugar level stabilize; insulin level drops; and because body is burning fat.