Researchers have identified a mechanism that drives hunger. A new study reports the sight or smell of food can temporarily turn of AgRP neurons, which drive the urge to eat. These neurons remain inactive until the brain receives a signal from the gut that calories have been consumed.
Researchers report the brain's ability to sense insulin and coordinate feeding with energy expenditure is controlled by a mechanism that is turned on after fasting to inhibit insulin response and conserve energy. After feeding, the mechanism is turned off to facilitate insulin response and expend energy. However, in obese people, researchers believe the switch may stay on all the time.