Life cycle assessment of food consumption in different cities: Analysis of socioeconomic level and environmental hotspots

This study presents a comprehensive life cycle assessment of the environmental impacts of dietary patterns in different cities, focusing on the correlation between food consumption and environmental impact. The functional unit was the food required to meet one person's yearly needs (1 Inh/year). To determine the quantity and type of food consumed, as well as the income level of the residents, 523 surveys were conducted in households in four cities in Chile (Iquique, Santiago, Temuco, and Coyhaique). Survey data were complemented with secondary information from national statistics and the Ecoinvent database. The environmental impact assessment was carried out using SimaPro, selecting the categories of global warming, terrestrial acidification, terrestrial ecotoxicity, freshwater ecotoxicity, freshwater eutrophication, land use, and fossil resource scarcity. The results show that higher-income households generate greater environmental impacts attributed to higher per capita food consumption. In the global warming category, the environmental impact can range from 1.08 kg CO₂ eq/inh/year for the first quintile to 2.15 kg CO₂ eq/inh/year for the fifth quintile in Santiago. In this category, the impacts in the highest quintiles can be up to 2.2 times greater than those in the lowest quintiles. Similarly, in acidification, this difference can reach 2.3 times. In the freshwater eutrophication category, the highest-income quintiles can double the environmental impacts compared to the lowest (I and II), mainly due to higher consumption of red meat and dairy products. The food production stage was the environmental hotspot across all evaluated impact categories, accounting for 45%–60% of the impacts in global warming, terrestrial ecotoxicity, and fossil resource scarcity; 74%–78% in terrestrial acidification, freshwater eutrophication, and land use; and 68%–71% in freshwater ecotoxicity. Meat was pinpointed as the primary environmental hotspot in global warming (44%), terrestrial acidification (56%), freshwater eutrophication (50%), land use (35%), and fossil resource scarcity (30%). Conversely, cereals are the primary environmental hotspot in terrestrial ecotoxicity (30%) and vegetables in freshwater ecotoxicity (18%). The geographical location of cities also influenced the environmental impacts of food consumption, primarily due to the types of available foods in regions near each city. Food availability conditions, diets, and quantities consumed, thus influencing environmental impacts. Finally, household incomes, the geographical location of cities, and the food production systems in each city determine the environmental impacts of food consumption. Different configurations of these variables create unique environmental impact profiles for each city. Despite this, typical environmental hotspots in food consumption were identified across all cities, enabling the implementation of strategies to minimize environmental impacts on a national scale. Thus, circular economy strategies linked to food production systems, as well as food loss and waste, could significantly reduce environmental impacts, presenting an intriguing opportunity for future research in this field.