Historically, the dogma was that body weight could only be affected by manipulating the long-term system (hypothalamus), as manipulations of the short-term system (brainstem) led to compensatory eating.

“when I was coming up learning about this stuff 15 years ago 20 years ago um you know it was uh the Dogma was you could only affect body weight through the long-term system by manipulating the long-term system because any manipulation you did of the short-term system in the brain stem the animal would would just compensate and there were these famous experiments where they would take cck which is a hormone just like gp1 inject it into rats inject it several times a day and cck is known to decrease the size of meals and it would decrease the size of meals but the rats would never lose any weight because they just eat more meals to compensate and they would just perfectly compensate by eating more meals and so the lore was it's just impossible the animal will always compensate unless you hit this body weight set point regulating area which is the hypothalamus the long-term system”