I picture the process this way. There's this constant urge to eat driven by enjoyment or to quiet those thoughts, rather than needing fuel. Then there's actual appetite where the body indicates it's time to eat for sustenance. Those medications cut down on the urge, and they ease the appetite signals too. Eventually though the urge reduction fades somewhat, so handling the appetite gets slightly tougher.
Folks have talked about how this medication starts feeling altered once you've taken it for a while. A few note intense hunger suppression at the beginning, but for others that impact fades gradually. I'm wondering if the shift stands out more in the mental cravings or the bodily sensations of needing food.