The World Bank post The high price of healthy food and the low price of unhealthy food by Derke Headey and Harold Alderman (7/23/19) explores the connection between food systems and wealth in a country, along with the impacts. For example, their graph here show a correlation between stunting in children and the caloric price of milk.
The metric we use to analyze the global food system from a consumer perspective is the “relative caloric price” of a given food. Take eggs, for example: how expensive is an egg calorie in Niger compared to the most important staple foods in that country? Egg calories in Niger are 23.3 times as expensive as a calorie from a staple food, such as rice or corn. In contrast, egg calories in the US are just 1.6 times as expensive as staple food calories.
The big picture:
Hence the problem in less developed countries is that poor people also live in poor food systems: nutrient-dense foods like eggs, milk, fruits and vegetables can be very expensive in these countries, making it much harder to diversify away from nutrient-sparse staple foods like rice, corn and bread. The problem in more developed countries is rather different: unhealthy calories have simply become a very affordable option. In the US, for example, calories from soft drinks are just 1.9 times as expensive as staple food calories and require no preparation time.
