Free fatty acids (FFA's) are higher in obese people, in addition to the higher levels of estrogens and lower testosterone. It's almost a guarantee that there would be liver damage, too, and that will ultimately end up deranging cerebral blood flow and glucose utilization. I've read some stuff about mitochondrial damage in hypothalamic neurons, partially due to the poor oxidation of FFA's. ATP depletion in some hypothalamic neurons or in the liver induces feeding behavior in rodents, and both of those factors are likely to be present in obesity. The adipocyte-derived cytokines, as some commenters mentioned, would worsen the fructose-induced ATP depletion in the liver. Supposedly, more preadipocytes can differentiate into adipocytes, too, in obesity. It's like a cancer, almost, and obese people have more adipocytes and not just larger adipocytes.