"There are plenty of reasons why Americans eat the foods they do, but two of the most important factors in determining diets are income levels and education. An analysis of data from the U.S. Department of Agriculture reinforces the notion that high earners with college degrees are more likely than other Americans to eat a healthy diet. In the opposite corner, lower-income Americans without high school degrees are more likely to drink whole milk and eat beans cooked with animal fats. Still, it’s hard to explain the divide between orange juice (high-income college grads), apple juice (low-income college grads), and whole oranges (low-income, less than a high school diploma)."
source: Bloomberg Businessweek
After living in America for a few years and now back in Europe, this really holds true in real life and when going to different supermarkets to see what is running out of stock quickly.