The discovery could lead to a huge breakthrough in treating obesity, which is reaching epidemic levels.
The new study helps solve the puzzle of how the body chooses to burn or store fat, and how it makes use of the energy from food that people eat.
Scientists looked specifically at how the body converts white fat, which stores energy, into the brown fat that is used to burn it. Fat is stored in special cells that are able to change from brown to white, and so help the body burn or keep the energy it eats.
They found that when a person eats, the body responds by circulating insulin. The brain then sends out signals to encourage the browning of fat, so that it can expend energy.
Likewise, when someone is not eating or is fasting, the brain sends instructions to the special cells known as adipocytes telling them to turn fat white. That helps store the energy when people aren’t eating, and makes sure that a person’s body weight stays stable.
That complex process is controlled by a switch-like mechanism in the brain. It switches itself off and on according to whether a person has eaten, and helps regulate how the body uses fat.