Such limits are stupid thing. Do not want.
Food already limits city development, there is no need for hard caps.
The problem with food limits is they encourage even more spam of undeveloped level 1 cities (as would any system that limits large cities but allows limitless small ones). Either way it would just exacerbate the current problem, which is covering the map in lots of cheap level 1 cities. Then caravans make it worse; all those level 1 cities can send a caravan to the capital, meaning that they generate more food than they use! Of course this is a problem no matter what caravans generate; if they increased gold instead, you'd have absurd gold generation in the capital, it's bad either way.
The funny thing is, Elemental had a decent solution to city spam in beta: your first city cost 100g to found, the second 200g, the third 300g, etc. (I may be misremembering the exact numbers, but something along those lines). There was also a greater emphasis on powerful resource-generation buildings that required higher level cities to build, rather than the current random map resources that any city can harvest. This meant that at a certain point, it became more worthwhile to invest in developing your current cities instead of founding another increasingly-costly level 1. City spam was still a problem back then, but at least it stopped being so good after a certain point (roughly 5-7 cities). Why they removed the founding cost, taking two steps backwards in progress against level 1 city spam, I'd love to know.
[I'm not mentioning the "destroy houses to recover food" thing since that's an obvious bug and can't be an intended part of the game mechanics - hopefully it gets fixed sooner rather than later.]