These changes in purchasing and consumption patterns are occurring in smaller cities and towns as well as the largest cities. Through their research and marketing efforts, food companies, of course, are shaping as well as responding to these demands. This transition corresponds closely to rises in income and the structural transformation of the food system, as seen primarily in industrialized and middle-income countries. Popkin, Adair and Ng (2012, p. 3) describe this phenomenon as "the primary mismatch between human biology and modern society". Awareness of these characteristics and the key actors who shape food systems will help identify where to intervene and what to do to create systems that help achieve good nutrition. Figure 1 provides a schematic overview of the elements of food systems and the broader economic, social, cultural and physical environment within which they operate.