Complexities and opportunities in monitoring and evaluating US and global changes by the food industry.

In developed nations and increasingly in the rest of the world, a large proportion of people's diets comes from manufactured food sources and food not produced at home. These types of products are constantly changing and have significant nutrition and health implications for the world's population. However, researchers, public health workers and policy makers face major complexities in understanding what these changes are and their relationships to diet and health outcomes. This paper will describe some of the complexities faced in monitoring and evaluating the nutritional composition of food products and what it means for population health. Importantly, no existing food composition database is able to keep up with the continuous reformulation and introductions and removals of packaged foods and food services. The paper will also discuss opportunities to improve and update the monitoring and evaluation of changes made by each of these key sectors of the modern food supply and how these changes can influence the nutrients purchased or consumed across the globe. The focus will be on the United States with some examples from other developed nations and a discussion of implications for low- and middle-income countries.