Abstract Middle-income countries face challenges in achieving diets that are both nutritionally adequate and environmentally sustainable, while income-related dietary heterogeneity adds uncertainty to population-wide dietary transitions. Here we investigate how income inequality shapes long-term dietary transitions from nutritional and environmental perspectives. We project Brazilian dietary patterns from 2020 to 2100 in scenario-based income pathways by integrating national-representative survey data with nutritional and environmental databases. We find that reducing income inequality improves dietary nutritional quality by 5.7%, and avoids 40-50% of the increase in dietary environmental impacts projected under income-inequality-increasing scenarios by 2100. However, inequality reduction is associated with a short-term worsening of dietary environmental impacts, with an average deterioration of 2.2% relative to the baseline scenario. These results highlight a trade-off between short-term environmental pressures and long-term nutrition and sustainability benefits, underscoring that income inequality reduction alone is insufficient and should be complemented by broader policy packages to promote dietary transitions.
Jia et al. (Wed,) studied this question.