HelloSailorSign posted:

That's difficult because most of the premium foods tend to be richer and thus harder on animals with sensitive stomachs... Though animals can also be sensitive to proteins, so switching from one brand to another may help if the proteins in it were changed.

Have you consulted with your vet on this? The length of time between eating overnight (and seeming correlated with longer times) can sometimes be associated with something called Bilious Vomiting Syndrome where if an animal doesn't eat for a prolonged period of time they throw up, but are totally fine otherwise as long as they get something to eat at more frequent intervals.