This doesn't change the fact that, relatively speaking, food is more expensive where the cost of living is more expensive and I do not dispute the fact that there are so called "grocery ghettoes".
This also doesn't change the fact that McDonald's burgers are vastly cheaper per Calorie than consumer-packaged vegetables or raw meats, but that is to be expected. The dressing on a salad is almost always more calorie-dense than the salad itself.
http://www.bls.gov/regions/mid-atlantic/data/AverageRetailFo...
My point above is that its a hard thing to mandate people eat food X when it might be $10 for 2,000 calories vs $2 for 2,000 calories. Its also a problem if the $10 option pre-supposed you buy in bulk, have access to refrigeration, and use spreadsheets to minimize wastage which otherwsie might be as high as 30% (making it $10 for 1400 calories down the gullet). My understanding of what little research has been done in this area has highlighted that the logistics and economics of fresh fruit/veg are heavily biased towards the upper/middle classes in many ways that are not obviously apparent nor addressed stricly by "guidance" on what is a "better" mix of foods. To use an analogy that people with white priveldge may be more able to understand: if I tell you to pack a weeks worth of fresh fruit and raw meat for a hike in yosemite, which you have to carry, and forbid you from eating anything like nuts/granola/raisins/cliffbars/dried meat, you probably would have a bad time lugging around that backpack over 10,000 ft passes and what not. The reality is that rich white people in the backcountry eat the same crappy food as inner city poor people once they lose access to refrigeration/storage and frequent/convenient resupply options. It doesn matter if you look at a pro bar or a nature valley or a power bar or a snickers. They are all interchangeble in that context and do the job, despite some being up to 7x as expensive. And nobody would call a diet of 8 probars and a pack of beef jerkey a day either healthy or well rounded, but you will survive your trip. Of course, if you eat this diet in a sedentary culture, you're BMI will get out of wack. But that is the power of the explanation.
The British supermarket they bought, Asda, is the cheapest major supermarket in the UK and it certainly sells fresh fruit and veg.
https://www.google.dk/search?q=asda&prmd=imvn&tbm=isch#tbm=i...
It's not fantastic quality, but it's very cheap.