agriculture Fun With Numbers

How viable is local food?

Before I begin, let me say there’s absolutely nothing wrong with supporting your local farmers through CSAs, farmers markets, or direct purchases. I’ve done similar things before and it makes sense in the same way I’d prefer to support local businesses over national chains It keeps money in the local economy and even if it didn’t, it is always more fun cheering for the home team.*

That said how viable is solely local food (usually with an arbitrary cut off of 30 or 50, or even 100 miles from its point of origin) for providing all the food for all the residents a major city?