Yes, 12 hrs. of not eating. Maybe not enough liquid during same time period.
15 yrs. ago I used to often jump onto the bike for a 16 km. ride to work after not eating for 12 hrs. No more than a glass of milk. Since it was a functional ride, I rode at a clip to get to work. By the end, I was ravenous.
Now I have to eat abit more to start off.