Most people are aware of ‘food deserts’ – regions where there are no grocery stores that sell real food. Though it’s typically examined as an urban phenomenon, this happens in rural areas as well and can be particularly bad there, as there is no public transportation making a trip to the store more costly.
I see no easy solution to the problem in either place, but it might be possible to create an app (working on it) that, for people in urban areas, could locate nearby grocery stores, provide optimal routes, and information on pricing and specials.