Carbon footprint of dietary patterns in Ontario, Canada: A case study based on actual food consumption

Recent studies have established the important contribution of food consumption to climate change, but the environmental implications of Canadians' dietary choices have not been studied in this regard. In this study, dietary intake data for 10,000 residents of Ontario, Canada were used to identify dietary patterns and estimate the Global Warming Potential (GWP) of food consumption and waste. Cluster analysis was used to identify seven dietary patterns (DP): vegan, vegetarian, pescatarian, omnivorous, and diets excluding red meat, beef and pork. Calorie-adjusted food baskets were formulated based on the most commonly consumed food items for each DP. Life cycle assessment was used to estimate GWP for each basket from farm operations, processing, distribution, to household processes (cooking, storage, food waste). The findings suggest that Ontario residents prefer DPs rich in animal products (particularly beef) that have very high GWP. Further, reducing food waste could reduce GWP by up to 8%. Though methods differ across studies and comparisons must be made carefully, available estimates of diet-related GWP from the US and UK are consistently higher than values in this study. Efforts are needed to standardize methods to facilitate a more cohesive body of evidence on the relevance of dietary choices and food waste to climate change. (C) 2017 Elsevier Ltd. All rights reserved.