[@KoL]
Might want to make funereal arrangements, because there's way more Alice where that came from.

[@Ashifili]
I can say, at the very least, that Alice's own snacks have not caused her to gain weight. Then again, she just kind of doesn't gain weight much. It might be different for others.

And the treats are the source of the power-ups. They have to be inside of you to work, so making yourself throw up won't do much other than free up room for different buffs if you were full before, while cancelling out what you had previously.

Throwing up also has the side effect of grossing Alice out and making her sad that you deliberately hurled up the food she made.