I think it's accepted now also that insulin blocks the effects of leptin (satiety hormone) on the brain. So a diet with an excess of carbs interferes with both fat regulation regulation but also intake.

Also I tried looking this up and failed. But I'm sure that leptin wasn't discovered until the war on fat was well underway. And the first instinct when it was discovered was to try to use it as a drug target (all these failed badly).