It seems we have three "circuits" involved. Dopamine, serotonin, end-opioid. Pre-components, Production, receptors, re-uptake. And there is where agreement ends. Something is not quite right, and cravings are the default occurrence.
Well, also the placebo effect also utilizes these same three circuits; we naturally make and our mind, body emotions all effect the amount we produce.
Seems that some foods disrupt equilibrium, wheat and dairy fats by providing exopioids peptides, sugar by flushing the serotonin from the gut to blood and hence to brain, and any anticipation screws with dopamine. Stress or emotional issue make thing more confusing by also using the same circuits. No shit, bat man. It is so interrelated, it might as well be the Yokums or the Weises, to which, I can say, are in my ancestral bush (more diverse than a tree).
So if we eat anything we like, (high palatable), desire, or look forward too, we may be causing it through the placebo effect, or we could be ingesting the building blocks to push production of one hormone up or down, turning a sensor or receptor on or off, or speeding or slowing uptake. It will be a while before anyone gets a handle on this stuff.
I guess the only think is to keep reading.