Dimensions underlying public perceptions and misperceptions of food's environmental impact

Food systems are a major contributor to environmental impacts such as greenhouse gas emissions and biodiversity loss, with widespread dietary changes required to avoid surpassing safe planetary boundaries by 2050. To promote dietary shifts among the public it is crucial to understand how people perceive the environmental impact of food products. However, prior investigations into this topic have covered only a narrow range of product types and elicited perceptions using researcher-imposed, single-item environmental friendliness scales—which might not align with consumers' underlying mental representations. We conducted a card sorting study in which UK participants (n = 168) organised a diverse range of supermarket food products into environmental impact categories that they created and labelled themselves. Participants subsequently viewed product-level scientific impact estimates and reported whether they were surprised by how high or low each impact was. Multidimensional scaling of card sorting data indicated a two-dimensional solution, with participants primarily distinguishing products by animal vs. plant-origin and level of processing. Category labels assigned during the sorting task and participants' self-reported surprise at scientific impact estimates suggested they tended to overestimate the impact of highly processed foods and underestimate the impact of water-intensive products (e.g., nuts). Furthermore, mixed-effects regression analyses indicated that surprise at how high the scientifically estimated impact of a given product was predicted intentions to consume less of that product in the future. Results provide novel insight into consumers’ mental representations of food sustainability, with implications for the development of information-provision strategies such as eco-labelling and public awareness campaigns.