Sustainable food choices require product-specific environmental footprints: The case of packaged food in Australia

The current food system is a major driver of global environmental change. Despite significant research interest in the environmental impacts of alternative diets, most studies estimate the effects of dietary shifts based on assumed changes in the consumption of raw agricultural commodities instead of simulating changes in the actual food and beverages consumed. In response to increasing consumer demand for product-specific health and sustainability labelling on packaged food products, it is necessary to develop robust environmental footprinting approaches to estimate the environmental impacts of foods and beverages available through retail outlets. This study quantifies the environmental impacts of 63,926 packaged food products in Australian supermarkets across five indicators including greenhouse gas emissions, land use, water use, acidification, and eutrophication potential. We integrated cradle-to-retail environmental estimates from life cycle assessment databases with ingredient proportions derived through a linear programming algorithm to measure product-specific impacts. Meat products consistently showed the highest impacts across all environmental indicators, while fruits, vegetables, plant-based meat alternatives, and non-alcoholic beverages had the lowest impacts. This study also shows that the dietary environmental footprints of Australian consumers can be significantly reduced by switching from high-impact to low-impact products within the same food category (e.g., meat products). Transitioning from high-impact to low-impact products across all food categories could reduce greenhouse gas emissions by up to 96 %, with synergies across all other environmental indicators. The comprehensive results of this study can empower consumers, producers, and governments to identify context-specific opportunities for improving food system sustainability in Australia.