Really interesting. Leptin resistance -> low leptin effect in the brain -> low dopamine levels -> intense pleasure-seeking.
That last step can take the form of eating, sex, drugs, videogames, exercise, caffeine, alcohol..anything that releases dopamine. Low dopamine (or reduced DRD2 anyway) is a hallmark of ADHD/ADD, hence why you engage in the above behaviors until someone gives you a stimulant, which doesn't get you hopped up like most people, but just gets your dopamine up to normal so you find ordinary things interesting again.
There's a reason why ADHD and obesity occur together with a pretty strong correlation in children and adults. They certainly both hit me at around the same time.
From reading Stephan and Dave's blogs, we can make some guesses about what causes the leptin resistance in question:
Wheat germ agglutinin
Excitotoxins (MSG, aspartame) (glutamate and aspartate can allegedly damage the hypothalamus)