Premium
Are Diets with a Lower Carbon Footprint More Nutritious? Evidence in the United States from the National Health and Nutrition Examination Survey
Author(s) -
Rose Diego,
WillitsSmith Amelia,
Heller Martin,
Meyer Robert
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.45.4
Subject(s) - national health and nutrition examination survey , population , environmental health , calorie , food group , carbon footprint , nutrient , medicine , demography , agricultural science , greenhouse gas , environmental science , biology , ecology , sociology , endocrinology
Although the US is the second highest‐ranked country in the world in greenhouse gas emissions (GHGE), and food production is a significant contributor to this, little is known about the impact of individual food choices in the US on GHGE or how this might relate to nutrient intakes. 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 on foods consumed by adults, 18–65 years of age (N= 13,204), from the National Health and Nutrition Examination Survey (NHANES) for 2005–2010 were converted to commodity form using resources from the US Environmental Protection Agency. The GHGE of these commodities were aggregated from a comprehensive review of life cycle assessment studies, which estimate environmental impacts throughout the “life” of a product, in this case foods. After matching the food choices of individuals to these GHGE, we ranked their 1‐day diets into quintiles based on GHGE per 1000 kilocalories, and compared the lowest and highest GHGE quintile groups. We focused on 12 key nutrients of concern that were identified in the Dietary Guidelines for Americans as either being under‐consumed by the US population or over‐consumed by it. T‐tests for differences in means were conducted using Stata 13.0 and made use of sample weights and survey design parameters published with the datasets. We estimate that the production of foods consumed by U.S. adults contributed 5.49 carbon dioxide‐equivalents per person per day (95% CI = 5.38 to 5.60), a value which is within the range of GHGE impacts found in European countries. The lowest GHGE diets (bottom quintile) scored better on five of the key nutrients, with significantly (p < 0.001) more vitamin E, folate, and dietary fiber per 1000 kilocalories and significantly (p < 0.001) less sodium and saturated fat than the highest GHGE diets. However, there was a higher content of three of the nutrients ‐‐ calcium, vitamin D, and potassium ‐‐ in the highest GHGE diets. We found similar results when limiting the sample to only those recalls that respondents identified as representing a “usual” amount. These results suggest that food patterns which are less environmentally impactful are more nutritious on several key dimensions, although not on all of them. The links between food choice, nutritional outcomes and environmental impacts are nuanced, which calls for more research and understanding of these interactions. Support or Funding Information This work was supported by the Wellcome Trust (grant # 106854/Z/15/Z).