TU.1.B || Future Sustainable Lifestyles – Individual Choices

Ridoutt, Bradley; Baird, Danielle; Hendrie, Gilly

Researchers often suggest large improvements in environmental sustainability are possible though dietary change. However, these studies tend to be based on a single environmental aspect (e.g. climate change), contrived dietary patterns that don’t reflect the full array of core and discretionary foods eaten, and some are not constrained by nutritional considerations. In this study, a weighted environmental impact (EI) score was developed using a distance-to-target approach using planetary boundaries. The included environmental aspects were water scarcity footprint, climate footprint and cropland scarcity footprint. To enable sensitivity analysis, three alternative weighting sets were also developed. The EI scores were calculated for around 150 processed and unprocessed foods in the Australian food system and used to assess 9,341 individual Australian adult daily diets obtained from the Australian Health Survey. To enable the identification of healthier diets with lower EI, a diet quality (DQ) score that assesses the level of compliance with the food based Australian Dietary Guidelines was also applied. Compared to the current average adult diet, with a DQ score of 41/100, diets in the lower EI and higher DQ (LEI-HDQ) quadrant had a DQ score of 58 or 59 (depending on the weighting model) and 35 to 42% lower EI score. However, when the current diet was scaled to conform with the Dietary Guidelines (DQ score = 100), EI scores increased marginally (5-7%). If the food choices of the LEI-HDQ quadrant were scaled to conform with the Dietary Guidelines, EI scores decreased by around 15%. It is possible to eat a recommended diet based on food choices common within the Australian population, but the environmental impact reduction potential is modest. The greater share of impact reduction may need to occur in the food production system.