We've been told before that more and more Americans are getting Type 2 diabetes (which is brought upon by obesity), but you may be surprised that the geographical distribution of the disease is actually quite striking*.
Healthline compiled data from CDC's Behavioral Risk Factor Surveillance system and the US Census Bureau's Population Estimates Program to create an interactive map where you can see the relationship between average household income, food desert (no, not "dessert" - food desert is an area where healthy and affordable food like fresh fruits and vegetables are not easily obtainable), and type 2 diabetes.
Link - Thanks Tracy!
*As you can see, diabetes is far more prevalent in the Southern United States (the red areas in Arizona are the Navajo and Apache Indian reservations)
http://visualizingeconomics.com/2007/08/11/united-states-poverty-map/
There are a few exceptions: in Southern Texas, poverty is higher but diabetes is not. But it's pretty much one-to-one elsewhere.
So, why this correlation? I think that poor people can only afford starchy food like potatoes and spaghetti, so they develop diabetes.