Something I was thinking about lately, so I decided to briefly look into it.. concept of food addiction. I found that food intake can/does cause release of endogenous opioids, then I quickly put the others together from neuroscience knowledge
Food addiction is apparently real. It seems food intake, especially sweets, such as sucrose, chocolate and such cause/increase the release of endogenous opioids. They then bind to the opioid receptors (specifically mu-opioid receptors are most important here). I'll also outline that there are 3 main hedonic "hotspots" per se.. they are mu-opioid receptors in the nucleus accumbens (NAc), cannabinoid receptors in the NAc, and Benzodiazepine-GABA system in the pons. These are the main areas regulating pleasure for something.. or simply "liking" it.. aka the hedonic aspect.
Conversely, addiction is mostly predicated on "wanting" (incentive salience) which is mediated through mesolimbic projections (VTA to NAc dopamine release mainly). Thus, dopamine (DA) doesn't cause pleasure, as it often spouted, but rather reinforces behavior, which is why it's the basis behind addiction.
Now, food intake causes the opioid release which binds to the mu-opioid receptors, which is a hedonic hotspot, explaining the pleasure you get from highly palatable foods. Subsequently, the opioid stimulation causes disinhibition of DA neurons by inhibiting ventral midbrain GABAergic projections.. furthermore, mu-opioid receptors can modulate the tonically active neurons (TAN), which can inhibit ACh release, causing burst-firing DA release. Two mechaniams of increased DA firing and thus "addiction" to food.
I'm not sure how severe it is or can be however. I'm also not sure on genetic variability possibly mediating this.. I'll look into that, but I have a hunch it would have a large genetic influence.. which may partly explain "obese" promoting genotypes. Simply surmise.