I think that adipose tissue is the biggest criminal when it comes to unwanted hunger, since it produces hormones to make you hungry the moment you actually risk losing weight.

Not sure how much the digestive neurons are involved with hunger actually, I thought its role was more about telling you which foods make you nauseous so you won't eat them, or subconsciously register which nutrients various foods have so you'ld crave the ones compensating for shortages more.