did anyone ever figure out how to share food?

[Kid R]

That would actually be a bad idea ... because that Great chef would get the settled spec bonuses from Representation and Sistine.

Good point. How about forget the specialist, and make the caravan unit create a special building instead (like e.g. great-scientist builds academy). This special building, the "Restaurant", adds a few food (like Baray adds +1PT, but more).

Hey presto ... etc. (this time no breakage of settled spec boni )

Again not really sharing food but at least transferring resources from one city to another. Could even have an equivalent one that ferries some over to help with those 1-tile island cities.

 

[strijder20]

You can share food (not just create food) too. Check Master of Mana (a modmod on FFH2).
It's actually quite simple. Just code a building which subtracts, say 2 per turn, from the building city, and supplies you with the 'Food supplies' resource (just like those American wonders do). Then you code another kind of building, which consumes one 'Food Supplies' (consuming isn't coded in the main game) and gives 2 food.