The buildingdata file has two flags you could experiment with -- food-provider and food-dropoff-point.
I have not found the flag "food-dropoff-point" - at least on the spread sheet ; but in any case, people take food only from the buildings flagged "food-provider." So Brf got El Malo barking up a wrong tree.
Opps! Artemais put it right in the same thread.
The flags in the building data file are bytes 51 and 52 for building use, where you can designate the building as a food provider, and the 14th byte after any guest/occupant slots. Also involved would be bytes 9 and 10 after guest/occupant slots--these are the ones that control input and output.
We still are not sure how to use them though.