Expected reduction in obesity of a 20% and 30% tax to Sugar-Sweetened-Beverages in Brazil: a modeling study

BackgroundThe consumption of sugar-sweetened beverages (SSB) is associated with obesity, metabolic diseases, and incremental healthcare costs. Given their health consequences, the World Health Organization (WHO) recommended that countries implement taxes to SSB. Over the last 10 years, Brazil has almost doubled its obesity prevalence, yet, in 2016, the Brazilian government cut 23 percentage points to existing federal SSB taxes to their current 4%. To simulate the potential impact of updating the fiscal policy towards SSB in Brazil, we aimed to estimate the price-elasticity of SSB and model the potential impact of a new 20 or 30% excise SSB tax on consumption, obesity prevalence, and healthcare costs. Methods and FindingsUsing household purchases data from the Brazilian Household Budget Survey (POF) from 2017/2018, we estimated constant elasticity regressions using a log-log specification by income level for all beverage categories: (1) sugar-sweetened beverages, (2) alcoholic beverages, (3) other beverages, and (4) low-calorie sweetened beverages. We estimated baseline intake for each beverage group using 24h dietary recall data from POF 2017/2018. Applying the price and cross-price elasticities to the baseline intake, we obtained changes in caloric intake. The caloric reduction was introduced into an individual dynamic model to estimate changes in weight and obesity prevalence. By multiplying the reduction in obesity cases during 10 years by the obesity costs per capita, we predicted the reduction in obesity costs attributable to the sweetened beverage tax. SSB price elasticities were higher in the low (-1.24) than in the high-income tertile (-1.13); cross-price elasticities suggest SSB were weakly substituted by milk, water, and 100% fruit juices. We estimated a caloric change of -17.3 kcal/day/person under a 20% excise tax and -25.9 kcal/day/person for a 30% tax. 10 years after implementation, a 20% tax is expected to reduce obesity prevalence by 6.7% and 9.1% for a 30% tax. These reductions translate into a -2.8 million and -3.8 million obesity cases for a 20 and 30% tax, respectively, and a reduction of $US -257.4 million and $US -345.9 million obesity costs over 10 years for a 20 and 30% tax, respectively. ConclusionsAdding a 20 to 30% excise tax on top of Brazils current federal tax in Brazil could help reduce the consumption of ultra-processed beverages, empty calories, and body weight while avoiding large health-related costs. Given the recent cuts to SSB taxes in Brazil, a program to revise and implement excise taxes could prove beneficial for the Brazilian population.