The “hunger hormone” ghrelin, which the body produces when it’s hungry, might also work in the brain to make some people keep eating “pleasurable” foods when they’re already full, UT Southwestern Medical Center scientists suggest.

The researchers also found that blocking the action of ghrelin, which is normally secreted into the bloodstream upon fasting or caloric restriction, prevented mice from spending as much time in the room they associated with the high-fat food.