Development of a sustainable diet index in US adults

Authors

Sukyoung Jung, Department of Epidemiology, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA. sukyoung_jung@gwu.edu.
Heather A. Young, Department of Epidemiology, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
Barbara H. Braffett, Department of Epidemiology, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
Samuel J. Simmens, Department of Biostatistics and Bioinformatics, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
Cynthia L. Ogden, Department of Epidemiology, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.

Document Type

Journal Article

Publication Date

4-10-2024

Journal

Nutrition journal

Volume

23

Issue

1

DOI

10.1186/s12937-024-00943-3

Keywords

Diet index; Dietary patterns; Environmental impact; Multidimensional assessment; Sustainable diets

Abstract

BACKGROUND: A transformation towards healthy diets through a sustainable food system is essential to enhance both human and planet health. Development of a valid, multidimensional, quantitative index of a sustainable diet would allow monitoring progress in the US population. We evaluated the content and construct validity of a sustainable diet index for US adults (SDI-US) based on data collected at the individual level. METHODS: The SDI-US, adapted from the SDI validated in the French population, was developed using data on US adults aged 20 years and older from the National Health and Nutrition Examination Survey, 2007-2018 (n = 25,543). The index consisted of 4 sub-indices, made up of 12 indicators, corresponding to 4 dimensions of sustainable diets (nutritional quality, environmental impacts, affordability (economic), and ready-made product use behaviors (sociocultural)). A higher SDI-US score indicates greater alignment with sustainable diets (range: 4-20). Validation analyses were performed, including the assessment of the relevance of each indicator, correlations between individual indicators, sub-indices, and total SDI-US, differences in scores between sociodemographic subgroups, and associations with selected food groups in dietary guidelines, the alternative Mediterranean diet (aMed) score, and the EAT-Lancet diet score. RESULTS: Total SDI-US mean was 13.1 (standard error 0.04). The correlation between SDI-US and sub-indices ranged from 0.39 for the environmental sub-index to 0.61 for the economic sub-index (Pearson Correlation coefficient). The correlation between a modified SDI-US after removing each sub-index and the SDI-US ranged from 0.83 to 0.93. aMed scores and EAT-Lancet diet scores were significantly higher among adults in the highest SDI-US quintile compared to the lowest quintile (aMed: 4.6 vs. 3.2; EAT-Lancet diet score: 9.9 vs. 8.7 p < .0001 for both). CONCLUSIONS: Overall, content and construct validity of the SDI-US were acceptable. The SDI-US reflected the key features of sustainable diets by integrating four sub-indices, comparable to the SDI-France. The SDI-US can be used to assess alignment with sustainable diets in the US. Continued monitoring of US adults' diets using the SDI-US could help improve dietary sustainability.

APA Citation

Jung, Sukyoung; Young, Heather A.; Braffett, Barbara H.; Simmens, Samuel J.; and Ogden, Cynthia L., "Development of a sustainable diet index in US adults" (2024). GW Authored Works. Paper 4736.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/4736

Department

Epidemiology