The second lens is how, since the 1970s, wages adjusted for inflation have stagnated, and starting about the same time—not coincidentally—the USDA switches policies and starts encouraging farmers to grow as much food as possible and you get this long period of declining food prices; you get this steady drop in food expenditures as a percentage of income. I don’t think you can run an economy with structurally stagnated wages without food being really cheap.
Really, really great interview at the Columbia Journalism review with Tom Philpott of Grist, pointing out the class issues in food politics.