Custo de dietas saudáveis e sustentáveis no Brasil

Abstract

Objective: This thesis aims to identify and compare the cost and environmental impact of the current diet of the Brazilian population with healthy and sustainable diets, examining variations by income level and analyzing the relationship between diet cost and quality. The specific objectives are: (1) to compare the cost and environmental impact of the current diet in Brazil with those of healthy and sustainable diets; (2) to assess differences in cost and environmental impact between healthy and sustainable diets and the current diet, stratified by income level; and (3) to estimate the association between diet cost and dietary quality, measured by the EAT-Lancet Index, based on food acquisition. Methods: This modeling study uses data from the 2017/18 Household Budget Survey (HBS) and the Food Footprints and Culinary Preparations Consumed in Brazil database. In Manuscript 1, the DIETCOST program was used to calculate the costs and environmental impacts of three dietary patterns: (a) the current diet, based on food acquisition data from the 2017/18 HBS; (b) a diet based on the recommendations of the Food Guide for the Brazilian Population (GAPB); and (c) a diet based on the EAT-Lancet Commission’s recommendations. Mean costs and environmental impact indicators (carbon footprint (CF) and water footprint (WF)) were compared using analysis of variance (ANOVA) and simple linear regression. In Manuscript 2, diets stratified by income levels were analyzed to assess the financial impact of diet costs on household budgets, using data from the National Food Survey (INA), a subsample of the 2017/18 HBS. Differences between the cost and environmental impact of diets were analyzed by ANOVA or Kruskal-Wallis (depending on the normality of the variable). The economic impact of each diet on household income was calculated to reflect the impact of the diet in the month (30 days). In Manuscript 3, food cost and quantity data from the 575 strata of the 2017/18 HBS were organized into 14 components to create the EAT-Lancet score, which measures diet quality. This index includes components recommended for higher intake (vegetables, fruits, whole grains, legumes, seafood, nuts, and unsaturated oils) and components for limited intake (beef, lamb, pork, poultry, eggs, dairy, potatoes, and sugar). Scores between 0 and 3 were assigned to each component, with a total possible score of 42 points. Results were stratified by per capita income, geographic region, and area of residence and compared using linear regression adjusted for high and low costs. In addition, the association between the EAT-Lancet score (and its emphasized and limited components) and diet cost (continuous) was analyzed for the total population and for income tertiles. Results: Key findings include Manuscript 1: The GAPB diet had the lowest cost per 1000 kcal (R$4.9), followed by the current diet (CBD) (R$5.6) and the EAT-Lancet diet (R$6.1). The environmental impact of the current diet was nearly double that of the GAPB and EAT-Lancet diets, with a CF of 3.1 kg/1000 kcal and a WF of 2,705 L/1000 kcal. A one standard deviation increase in CF was associated with an R$0.48 increase in the cost of the current diet, like that observed for WF (R$0.58); Manuscript 2: The EAT-Lancet diets had higher costs for low-income populations, increasing the budgetary impact (48.18% vs. 45.22% in the current diet), while reducing the impact for higher-income groups (14.49% vs. 15.91%). Environmentally, the current diet had a greater impact due to the high consumption of red meat, discretionary foods, and sugar-sweetened beverages; & Manuscript 3: The mean EAT-Lancet score was 18.65 points. Total scores showed no significant difference between low- and high-cost diets. However, limited intake was more pronounced in low-cost diets, while high-cost diets featured emphasized foods such as fruits, vegetables, and seafood. Each one-point increase in the EAT-Lancet score was associated with a R$0.38 reduction in cost, driven by lower costs in the Limited component, especially among the lowest-income strata. However, higher scores for emphasized foods increased costs in the lowest tertile. Final Considerations: The thesis suggests that the cost of healthier diets may be a barrier to access for the Brazilian population, particularly among lower-income groups. Lower diet costs were associated with lower environmental impacts, especially in healthy and sustainable diets. In terms of environmental impacts, the current diet of the Brazilian population has almost twice the environmental footprint when compared to healthier and more sustainable diets. These findings highlight the need for multisectoral public policies to support and promote the adoption of healthier and more sustainable, yet more affordable, dietary patterns.