I don't think it is "urban living" so much as just modern living. While people in rural and suburban areas are more likely to have some form of exposure to locally grown produce, they still for the most part live in the same kind of economy as urban areas. I currently live in a suburb surrounded by strawberry farms, avocados, etc. And our grocery stores are just as likely to have strawberries and avocadoes from Mexico.

People in rural areas like where I grew up, might be more likely to have a garden, but most don't, and they still get most of their calories from the grocery store. I grew up on a cattle ranch and while that might give me more "connection" to my food, we still bought a lot of our beef at the grocery store because finishing and butchering a cow is expensive and time consuming and requires lots of long term freezer storage. Today's modern rural family is pretty similar to an urban one except they drive a lot farther to do anything.