The premise that hunger makes food look more appealing is a widely held belief.
Prior research studies have suggested that the hunger hormone ghrelin, which your body produces when it's hungry, might act in your brain to trigger this behavior.
New studies suggest that ghrelin might also work in your brain to make you keep eating “pleasurable” foods when you're already full.
Scientists previously have linked increased levels of ghrelin to intensifying the rewarding or pleasurable feelings that can be obtained from cocaine or alcohol.
Researchers observed how long mice would continue to poke their noses into a hole in order to receive a pellet of high-fat food. Animals that didn't receive ghrelin gave up much sooner than the ones that did receive ghrelin.
Humans and mice share the same type of brain-cell connections and hormones, as well as similar architectures in the “pleasure centers” of the brain.