Ten-Year Changes in Global Warming Potential of Dietary Patterns Based on Food Consumption in Ontario, Canada

Many studies have evaluated the life cycle environmental impacts of diets based on a single period, but few studies have considered how environmental impacts of diets change over time, even though dietary patterns (DPs) change due to policy and socio-demographic factors. This study evaluated changes in the global warming potential (GWP) of DPs in the province of Ontario, Canada, using a life cycle assessment. We quantified the farm-to-fork GWP of six DPs (Omnivorous, No Pork, No Beef, No Red Meat, Pescatarian, and Vegetarian), using dietary intake data from a 2014 and 2015 survey. Throughout this period, the biggest decrease in GWP was for DPs containing beef, even though these DPs still have the highest GWP (3203 and 2308 kg CO2e, respectively, based on the annual energy intake of one individual). Across all DPs, plant-based proteins contributed less than 5% to GWP, while meat and fish contributed up to 62% of the total GWP. Ten-year GWP reductions are insufficient to meet climate change and other sustainability goals, and major dietary shifts are needed, particularly substituting animal-based proteins with plant-based proteins. To design effective interventions for shifting towards sustainable diets, research is needed to understand how socio-demographic and regional differences influence individuals’ food choices