There are a couple articles I can link when I get home. They studied a similar phenomenon in some Brazilian cities. There are several factors involved, including food losses due to distance to consumption and the fact that smaller producers tend to grow more diverse food.
Logistics are something too complex. Your statement makes me think you’re referring to a scenario with one source of a product and either one consumer area or several ones. In that cass, indeed, a more denser region would make it easier, but the scenario I described consists of production decentralized and closer to consumption, making logistics easier and cheaper, with fewer middlemen.
But maybe I didn’t explain it all very well. I have a couple or articles bookmarked in my pc that I will link here when I have the chance.
I just hope my memory isn’t playing tricks on me, because it so, it’s gonna be really shameful lol.