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Résumé (français)

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Résumé (anglais)

What humans eat can have a significant impact on ecosystems and the climate. In order to attain the climate targets to keep global warming below 1.5 degrees Celsius, it is important to reduce consumption of carbon-intensive food products. Many studies have quantified the environmental impacts of food consumption. However, most of these prior diet-related environmental assessment studies have evaluated impacts based on a snapshot of food consumption, instead of evaluating the changes in food-related environmental impacts over a period of time. Understanding these changes is important in determining what factors affect consumer food consumption behaviours that would shift their food consumption patterns towards less resource intensive products. This thesis evaluates the changes in food, nutritional value, and carbon footprint (CF) of dietary patterns in Ontario in the last decade, broadly in three steps. First, change assessment is conducted by comparing the overall food consumption based on the 24-hour recall food intake data from the Canadian Community Health Survey-Nutrition in 2004 and 2015. Then seven dietary patterns are identified by analyzing the food types of each survey participant and Life Cycle Assessment is used to quantify CF of these dietary patterns. Canada’s Food Guide is used to assess the nutritional quality of actual dietary patterns, and then alternative nutritionally-balanced and low carbon dietary patterns are formulated and their CF is determined. The results suggest that: 1) overall, Ontarians are eating less red meat and more poultry and drinking less beverages high in sugar content; 2) Ontarians continue to overconsume daily protein, possibly because they do not consider protein from non-meat products, such as milk and cheese; 3) the CF of Ontarians food consumption has decreased in the last decade, specifically due to reductions in beef, which is the most carbon-intensive food product; and 4) also, the CF of nutritionally-balanced diets has decreased for all dietary patterns, only exception is Pescatarian that showed a slight increase. Changes in types and amounts of food consumed could be a result of health concerns, increase in climate change awareness, economic or cultural fluctuations. Overall, this thesis improves our understanding of the CF and nutritional assessment of Ontarians’ current food consumption and how this has changed in the last 10 years. By determining and understanding changes, this research could also be helpful to identify strategies to shift Ontarians’ food consumption behaviors towards nutritionally-balanced and low carbon-intensive food choices.