I'm pretty sure food waste increases with era (correlation, not causation), because you have cities with more people, and you're producing more food per unit of population. I've found in my 40.0 game (I think there is a save on here somewhere), food waste becomes huge later in the game. New cities in the Information Era (where I left off) can sometimes waste more food than they consume.
I like the idea of limiting growth, but I think we need a different concept. We can keep food waste, but it would have a smaller impact, and be affected by more appropriate factors (like civics; a capitalist economy, for example, wastes more food than a communist economy, because food is thrown out if people can't afford it).
I think something regarding birth rate and infant mortality should affect food. Perhaps there could be auto-buildings from unhealth (net or gross). Various buildings can be edited to have a reduction in food or growth. For example, the Omega Child Crew could reduce food/growth, since children who work don't grow as old or reproduce as much, sometimes dying from too much work. There could be a replacement building in the Industrial Era, to reflect the child labor laws of the time. The Omega Child Crew is a strong building, so giving it a downside would, if anything, make you think whether or not you want to build it in every city.
Basically, any building that reflects overexertion of a workforce could limit population growth (like slavery buildings/specialists).
per pop to 1.5 instead of 1.
doesn't necesarely benefit the player and forces the player to micromanage spamming food caravans/merchants.
(which is never a problem) and additional 
