The hypothesis for leptin as a diet drug was that activating the pathway would trick the brain into thinking there were more energy reserves, reducing hunger and promoting fat loss.

“the thought is which I think is absolutely correct is that this this hormone leptin is is part of this negative feedback loop from the fat to the brain that basically tells you about your level of body fat reserves and how urgent it is to find the next meal fascinating as I recall um Amin Pharmaceuticals own the patent for leptin in hopes that it would become the Blockbuster diet drug the logic being that if you were to take this hormone somehow or activate this pathway that the brain would be tricked into thinking that there was more body fat more energy reserves than there was and then people would uh basically be less hungry eat less and lose body fat”