Same thing happening for me. Had surgery Monday 3/13 and I wake up feeling hungry. I think it is an empty stomach with too much acid rumbling or even boredom. I am craving late night snacks like I always have but know I don’t need them. My mind playing tricks on me.
Smelling good is also making my stomach growl but that may also be a desire to eat that food but not actually needing to eat. Good luck!