This point made by Bryan Walsh gets to the core of the economic condition and historical position of postindustrial/late/advanced capitalism....

A study in the American Journal of Clinical Nutrition found that a dollar could buy 1,200 calories of potato chips or 875 calories of soda but just 250 calories of vegetables or 170 calories of fresh fruit. With the backing of the government, farmers are producing more calories — some 500 more per person per day since the 1970s — but too many are unhealthy calories. Given that, it's no surprise we're so fat; it simply costs too much to be thin.