You answered your own question. “… reducing appetite…” . It’s all about CICO but also not about that. The real game-changer is the fact people don’t have to have the will power of a Zen guru to fight off the hunger pangs. That’s the 90% you should take away from this. It’s almost effortless, and that’s a huge deal. People have been proposing what you say for a 100 years and obesity only got worse. If a drug can fix it relatively safely more power to them.