Socioeconomic status, energy cost, and nutrient content of supermarket food purchases.

Background: The relative affordability of energy-dense versus nutrient-rich foods may promote socioeconomic disparities in dietary quality and obesity. Although supermarkets are the largest food source in the American diet, the associations between SES and the cost and nutrient content of freely chosen food purchases have not been described.

Purpose: To investigate relationships of SES with the energy cost ($/1000 kcal) and nutrient content of freely chosen supermarket purchases.