Development and validation of an individual sustainable diet index in the NutriNet-Santé study cohort

Abstract

In the current context of unsustainable food systems, we aimed to develop and validate an index, the sustainable diet index (SDI), assessing the sustainability of dietary patterns, including multidimensional individual indicators of sustainability. Based on the FAO’s definition of sustainable diets, the SDI includes seven indicators categorised into four standardised sub-indexes, respectively, environmental, nutritional, economic and sociocultural. The index (range: 4–20) was obtained by summing the sub-indexes. We computed the SDI for 29 388 participants in the NutriNet-Santé cohort study, estimated its validity and identified potential socio-demographic or lifestyle differences across the SDI quintile. In our sample, the SDI (mean=12·10/20; 95 % CI 12·07, 12·13) was highly correlated to all the sub-indexes that exerted substantial influence on the participants’ ranking. The environmental and economical sub-indexes were the most and less correlated with the SDI (Pearson R2 0·66 and 0·52, respectively). Dietary patterns of participants with a high SDI (considered as more sustainable) were concordant with the already published sustainable diets. Participants with high SDI scores were more often women (24 %), post-secondary graduates (22 %) and vegetarians or vegans (7 %), without obesity (16 %). Finally, the SDI could be a useful tool to easily assess the sustainability-related changes in dietary patterns, estimate the association with long-term health outcomes and help guide future public health policies.

Method for the Development of WISH, a Globally Applicable Index for Healthy Diets from Sustainable Food Systems

“…This scoring system was adopted, as the EAT-Lancet commission considered environmental factors and health factors when setting the recommended consumption amounts for the food groups. Previous scores measuring the healthiness and environmental sustainability of the diet use a scoring for the healthiness of the diet (using e.g., a dietary diversity score or nutrient data) and a scoring for the environmental impact (using LCA data) of the diet and combine this in one overall score [18,20]. Another index based on the EAT-Lancet recommendations uses a binary scoring system where the lowest and highest recommended intakes were taken to assess whether participants met each of the recommendations (i.e., above the minimum intake or below the maximum intake) [31].…”

“…The outcomes of indicators assessing the impact of the diet on the environment can vary tremendously across countries for the same food product as sustainability depends on the way the product is produced, stored, transported, processed and packaged. Indices combining the healthiness and environmental impact of the diet in one score are available [18,19]. However, such indices have been developed for high-income countries and need information from life-cycle assessment databases, which are often not available for many products consumed in LMICs [20].…”

Advances in dietary pattern analysis in nutritional epidemiology

“…Lately, DP very recently started to take effects beyond health outcomes into account and implications in relation to sustainability and environmental impact have come into focus. Yet, only very few studies have addressed sustainability aspects in exploring DP to-date [14,15,[125][126][127][128]. Thus, there is a strong need to investigate the broader impact of diets on the environment and link these to disease prevention, for which DP analysis has the means to respectively expand its scope and close the gap of analyses of sustainable DPs with chronic disease risk.…”

Nutritional Quality and Health Effects of Low Environmental Impact Diets: The “Seguimiento Universidad de Navarra” (SUN) Cohort

“…The definition of sustainable diets stresses the necessity of considering several aspects when promoting dietary patterns –the environment, nutrient adequacy, culture, accessibility or economic affordability- without prioritizing one over the others. Although some trade-offs among these aspects exist [ 27 ], recent publications show that diets that consider several dimensions, such as nutrient adequacy, environmental impact, and affordability, could be culturally acceptable and accessible and still be promoting health benefits [ 44 , 66 , 67 ]. Forthcoming dietary studies should take a comprehensive point of view if a greater knowledge of sustainable diets and their implementation is the objective [ 68 ].…”