A single specific and actionable swap recommendation can lead to substantial reductions in households’ dietary carbon footprints

Dietary change can lower environmental impacts, yet current guidance can still lack the specific, actionable instructions to prompt actual behaviour change. We use household food purchase data collected via the loyalty program of a major Swiss retailer (N = 347 households; 713,645 purchases; 73,662 baskets) to identify and simulate dietary change strategies that provide specific and actionable product swap recommendations to households based on their real-world purchasing behaviours. Assuming complete acceptance of swap recommendations to determine the maximum carbon emissions reduction potential, our simulations show that households could cut the carbon emissions of their food purchases by 26 % by swapping just one animal product for its plant-based alternative per shopping trip, representing two-thirds of the total potential reduction from replacing all animal product purchases (40 %). Alternatively, swapping a single food category (e.g. pork meat), personalised according to their historic purchases, leads to an average reduction of 15 %. These findings suggest that existing retailer infrastructure can be utilised to provide consumers with specific and actionable recommendations, personalised according to their past purchases or delivered in real-time, to meaningfully lower their carbon emissions.