A new study helps to explain how leptin, a hormone produced by fat tissue, influences your motivation to eat.
The researchers described for the first time a collection of leptin-responsive neurons in the brain's lateral hypothalamic area (LHA). Those LHA neurons feed directly into the mesolimbic dopamine system, which controls the rewarding properties assigned to things.
The study therefore adds to growing evidence that leptin doesn't turn your appetite on and off just by controlling whether you feel hungry or full. It can also make you want food more or less regardless of hunger.