Ghrelin, a hormone released from the GI tract, increases desire to eat by stimulating brain areas that promote eating and creating food anticipatory signals.

“Well, how does it do that? It does that again by impacting neural circuits within the brain, neural circuits that include what we call the brain stem autonomic center. So it tends to make you feel alert and quite, we say, high levels of autonomic arousal. If you haven't eaten in a while, you might think that you just get really exhausted, right? Because we all hear that food is energy and caloric energy is what we need to burn, but you actually have a lot of energy stored in your body that you would be able to use if you really needed energy. But typically if we haven't eaten in a while, we start to get agitated and we get agitated by way way of release of the neuromodulator epinephrine, which causes us to look around more, move around more, and seek out food.”

“it's called gin it's spelled g HR e l i n gin is released actually from the GI tract and its main role is to in increase your desire to eat and it does that through a variety of mechanisms part of that is to stimulate some of the brain areas the actual neurons that make you want to eat in addition it creates food anticipatory signals within your nervous system”