A Novel Approach for Determining the Environmental Impacts of Individual Food Choices in the United States

Abstract

USDA and DHHS excluded sustainability as a topic for consideration in developing the 2015 Dietary Guidelines for Americans, contrary to recommendations by an expert advisory committee. While significant progress has been made in Europe and elsewhere in documenting the environmental impacts of different diets, very little work on this has been undertaken in the US, which might help explain their decision. To address this gap, we developed a novel approach to study the environmental impacts of individual food choices in the US. Individual 24‐hour recall data (N=28,276) from the National Health and Nutrition Examination Survey for 2005–2010 were converted to commodity form using resources from the US Environmental Protection Agency. There were 2.63 million food item/recipe components consumed by these individuals on the two days of recall, and these were converted to 461 different commodities. The environmental impacts of these food commodities – principally greenhouse gas emissions – were obtained from a comprehensive review of published life cycle assessment (LCA) studies. The LCA approach assesses inputs and outputs in the production, distribution, and consumption of products, and has seen increased application to foods in recent years. By matching the food choices of individuals to environmental impacts, we can quantify the impact of dietary choices on greenhouse gas emissions and other environmental impacts. Using aggregate agricultural food balance sheet data, we previously estimated mean greenhouse gas emissions from the U.S. diet to be 5.0 kg of carbon dioxide equivalents per person per day. The approach reported here will allow us to refine that estimate, and analyze the variation in the US population of this outcome by demographic and socio‐economic characteristics, as well as by diet knowledge and health behaviors. This cross‐disciplinary research demonstrates an approach that can inform future policy discussions regarding dietary recommendations and their potential impacts on sustainability.Support or Funding InformationThis work was supported by the Wellcome Trust (grant # 106854/Z/15/Z).