Marksman77
Aethernaut
Ok, I'm not perfectly honest, as I don't know for sure the answer for my own question 
But from what I understand there are no good answers yet

But from what I understand there are no good answers yet

Blast.
I've just realised you could get a much higher maximum figure than the one I calculated, but it would require a RIDICULOUS (IE impossible) BFC. The one i've calculated is improbable, but possible.
Throw some ideas out there, being a bit of a novice at this I may have missed some things, or failed to understand how the game mechanics work with regard to food and health and all that. City of a thousand slums is a good place to start, but this figure I've got on the scrap of paper in front of me doesn't need it.
Throw Yggdrasil somewhere in that mix... I think that'd be worth more than a farm.
EDIT: What I'm curious about is the maximum you can get without using Great Merchants...
The maximum food you can get without GMs is 326 (9 food*36 tiles + 2 on the city). Assuming an infinite amount of health (using Life Mana) that means you can get to size 326 using Sacrifice the Weak. Yggdrasil doesn't improve this as it provides a maximum of only 8 food (seven naturally with the required techs plus one from an Ancient Forest) whereas farmed, irrigated Corn on Ancient Forests using Agriculture provides 9.
Unless you are the Calabim and get another 2 from your unique Granary(and yes, FF fans, also unless you are the Mataztl and can get tons of food from Trade Routes)