I'll set aside the other health benefits for a sec, that's a complicated topic.
What do you say to the BBs who ask for advice on appetite boosting compounds, because they find it physically impossible to eat enough calories to meet their goals?
Food seems completely unappetizing, their throats close up, get gastric reflux, want to puke (and may do so) at the thought of eating one more bite:
Then, they use one appetite boosting compound or another, and suddenly they can eat plenty more.
Shouldn't they be able to "willpower" through it without using a drug to help, yet it's described as physically and psychologically impossible for them.
I'm not being sarcastic or argumentative, just changing the angle.
If an appetite booster allows them to eat, shouldn't it be possible without that just through willpower? That dynamic seems to indicate there's a powerful energy intake regulating mechanism that's capable of physically and psychologically stop you from eating pretty effectively, and presumably exerts an equally strong effect when it wants you to eat.