Understanding sustainable diets: a descriptive analysis of the determinants and processes that influence diets and their impact on health, food security, and environmental sustainability

Abstract

The confluence of population, economic development, and environmental pressures resulting from increased globalization and industrialization reveal an increasingly resource-constrained world in which predictions point to the need to do more with less and in a "better" way. The concept of sustainable diets presents an opportunity to successfully advance commitments to sustainable development and the elimination of poverty, food and nutrition insecurity, and poor health outcomes. This study examines the determinants of sustainable diets, offers a descriptive analysis of these areas, and presents a causal model and framework from which to build. The major determinants of sustainable diets fall into 5 categories: 1) agriculture, 2) health, 3) sociocultural, 4) environmental, and 5) socioeconomic. When factors or processes are changed in 1 determinant category, such changes affect other determinant categories and, in turn, the level of "sustainability" of a diet. The complex web of determinants of sustainable diets makes it challenging for policymakers to understand the benefits and considerations for promoting, processing, and consuming such diets. To advance this work, better measurements and indicators must be developed to assess the impact of the various determinants on the sustainability of a diet and the tradeoffs associated with any recommendations aimed at increasing the sustainability of our food system.

Conflict of interest statement

Author disclosures: J. L. Johnston, J. C. Fanzo, and B. Cogill, no conflicts of interest.

© 2014 American Society for Nutrition.

Figures

FIGURE 1

The key components, determinants, factors, and processes of a sustainable diet. The large green ovals represent the key components of a sustainable diet, as defined by FAO and Bioversity in 2010 (18). They include the following: 1) well-being, health, 2) biodiversity, environment, climate, 3) equity, fair trade, 4) eco-friendly, local, seasonal foods, 5) cultural heritage, skills, and 6) food and nutrient needs, food security, and accessibility. Each key component is directly connected to the pink circle in the center of the image that represents sustainable diets. Each key component relates to and influences one another and the sustainability of diets, represented by their direct connections to sustainable diets (pink circle), and one another (green ovals). Within each key component (each green oval), we list the different factors and processes that make up the influence of a particular component on what comprises a sustainable diet. This representation helps demonstrate the interdependence and influence that exists across the system that is depicted and how changes to 1 or more factors or processes can influence other factors and processes within the same key component category and others (40). Consistent with the current FAO definition for sustainable diets and for the sake of explanation, the categories, factors, and processes represented do not carry specific weights with respect to their influence on sustainable diets. Currently, it is assumed that all elements are weighted equally in their contributions to what comprise a sustainable diet. In this review, it was discussed that, with tradeoffs across these determinants, they can pull the sustainability of a diet in 1 direction or another. Finally, the key components of sustainable diets and factors and processes contained within each component (each green oval) fall into 5 overarching categories of analysis: 1) agriculture, 2) health, 3) culture, 4) socioeconomic, and 5) environment. Each of these categories is discussed in detail in the review. Adapted with permission from reference .

FIGURE 2

Schematic representation of an unsustainable diet. Adapted with permission (28). The image provides a visual representation of how the changes or deficiencies associated with the various determinants, factors, or processes of a particular key component of sustainable diets can “shrink” the sustainability of a diet. This is denoted by the smaller pink circle (relative to Fig. 1) at the center that represents sustainable diets. The reduction in the sustainability of the diet is the result of unsustainable agricultural practices and their impact on the environment: water use for irrigation and high GHGEs both denoted in bold dark gray. These determinants are contained within 2 component categories that are depicted in shaded gray ovals and shrunken in size due to the negative/deficient contribution to sustainable diets. Similar to Figure 1, the large green ovals represent the key components of a sustainable diet, as defined by FAO and Bioversity in 2010 (18). This representation helps demonstrate the interdependence and influence that exists across the system that is depicted and how changes to 1 or more factors or processes can influence other factors and processes within the same key component category and others (40). Adapted with permission from reference 28. GHGE, greenhouse gas emission.