Essays on environmental impacts of dietary changes in Brazil

Abstract

In this thesis, we investigate the environmental impacts of dietary habits and choices in Brazil and explore demand-side strategies for mitigation. We divided our research into two main chapters. The first chapter examines the nutritional and environmental impact of different diet types in Brazil and dietary transitions. We used nationwide dietary intake microdata from the Household Budget Survey (POF) from 2017-2018, in addition to environmental indicators. We estimated the carbon, water, and ecological footprint for eight distinct diet patterns, including vegan, vegetarian, pescatarian, flexitarian, and a Brazilian typical diet. The results demonstrate that strictly plant-based diets achieve the greatest reductions in environmental footprints when compared to animal-based diets. Meanwhile, pescatarian, vegetarian, and ruminant-replaced diets offer a "win/win" balance by providing moderate environmental benefits alongside greater nutritional diversity. The research additionally highlights that even partial dietary transitions, such as changing eating habits for just a single day, can lead to relevant environmental reductions. In the second chapter, we evaluated how a system of environmental food taxes and subsidies could be used to effectively reduce environmental impacts from the agrifood sector in Brazil. Using the most recent microdata from the POF, we estimated elasticities for 16 food groups through a Quadratic Almost Ideal Demand System (QUAIDS) model, and simulated tax-system scenarios including standalone environmental taxes, subsidies for sustainable foods, and a combined approach. Our results show that while standalone taxes on high-emitting foods reduce carbon footprints, they are regressive and may risk exacerbating food insecurity. Conversely, a dual-incentive policy combining taxes with subsidies emerges as the optimal choice, combining a reduction in environmental losses with better social equity. Ultimately, this research provides relevant evidence for policymakers, illustrating that demand-side interventions, such as encouraging dietary shifts and implementing targeted fiscal policies, can serve as an efficient complement to traditional command- and-control environmental strategies in Brazil. Keywords: dietary change; Life Cycle Assessment; Greenhouse-gas Emissions; environmental taxes; Food Demand System; sustainability; environmental impact.