One of the core parts of Egyptian offering practice is that offerings are returning to the gods what They have given, so that they are both capable of continuing to support the cycle of creation and positively inclined to do so to the benefit of people.
That's a really interesting perspective.
If the offerings are food, does that mean that the gods literally take sustenance (i.e., nutrition of some kind) from the offerings? How do non-food offerings fit in? Are there acceptable kinds of offerings that are not tangible -- like doing volunteer work?
Are worshipers required to make offerings? What if they don't?