While it's not a choice, there are things that influence appetite; for example, going for high calorie but poorly filling food and drink (e.g. soda), or the (I'm handwaving here) "moreish" foods.
It isn't. But change like that is exactly what you need to do. If it's good or bad to change it via a drug instead of mental discipline is another question.
But you could change your food and eat tons of it. I am a pretty slim person and i eat a lot compared to my friends. I also don't do much sport and as a developer is sit a huge part of the day.
So for me it comes down to WHAT i eat and it's serving me pretty well. You don't need to fight your appetite, you can serve it and still loose weight.
In my experience, bodyweight functions like a closed loop control system that uses hunger signals to address the error signal. The error signal is basically (greatest weight attained) - (current weight) where the greatest weight attained value is severely lag filtered, say 2 years or more. The system seems to be very strong in response to rate changes in the error. The integral of the error seems to be pretty strong over a period of say 5-7 days.
Congratulations on your weight loss, does your experience compare to what I've described?