The "true cost" of food is made even more complex in countries like the U.S. where 66% of people are obese or overweight. The cost of obesity is tremendous, affecting everything from health care costs, to clothing costs (for every extra inch you are around the waist, you need several square feet of fabric), to transportation fuel costs (it costs more to move obese people around). So perhaps charging much more for food over 2,000 kCal/day per person makes a lot of sense. There are externalities that we all end up paying for.