Global growth of "big box" stores and the potential impact on human health and nutrition.

Despite a large body of literature on the food environment, little is known about the role of supercenters in human nutrition and health. The objectives of this review are to examine what is currently known about the association between supercenters, nutrition, and obesity, to identify how supercenters may affect disparities in food access and nutritional quality of food purchases, and to document the rapid rise of supercenters as a source of food purchases in the United States. A case study of Wal-Mart, the largest food retailer in the United States, is presented that demonstrates the major and increasing role of supercenters as a source of packaged food purchases in the United States, particularly among low-income households, as well as the role of supercenters in supplying key nutrients. Taken together, this review and case study highlight the dominant role of supercenters in the US diet and the need to better understand how supercenters can be leveraged to improve the nutritional quality of what consumers buy and eat.