Estimated reduction in obesity prevalence and costs of a 20% and 30% ad valorem excise tax to sugar-sweetened beverages in Brazil: A modeling study.

Background: The consumption of sugar-sweetened beverages (SSBs) is associated with obesity, metabolic diseases, and incremental healthcare costs. Given their health consequences, the World Health Organization (WHO) recommended that countries implement taxes on SSB. Over the last 10 years, obesity prevalence has almost doubled in Brazil, yet, in 2016, the Brazilian government cut the existing federal SSB taxes to their current 4%. Since 2022, a bill to impose a 20% tax on SSB has been under discussion in the Brazilian Senate. To simulate the potential impact of increasing taxes on SSB in Brazil, we aimed to estimate the price-elasticity of SSB and the potential impact of a new 20% or 30% excise SSB tax on consumption, obesity prevalence, and cost savings. Methods and findings: Using household purchases data from the Brazilian Household Budget Survey (POF) from 2017/2018, we estimated constant elasticity regressions. We used a log-log specification by income level for all beverage categories: (1) sugar-sweetened beverages; (2) alcoholic beverages; (3) unsweetened beverages; and (4) low-calorie or artificially sweetened beverages. We estimated the adult nationwide baseline intake for each beverage category using 24-h dietary recall data collected in 2017/2018. Taking group one as the taxed beverages, we applied the price and cross-price elasticities to the baseline intake data, we obtained changes in caloric intake. The caloric reduction was introduced into an individual dynamic model to estimate changes in weight and obesity prevalence. No benefits on cost savings were modeled during the first 3 years of intervention to account for the time lag in obesity cases to reduce costs. We multiplied the reduction in obesity cases during 7 years by the obesity costs per capita to predict the costs savings attributable to the sweetened beverage tax. SSB price elasticities were higher among the lowest tertile of income (−1.24) than in the highest income tertile (−1.13), and 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 under a 30% tax. Ten years after implementation, a 20% tax is expected to reduce obesity prevalence by 6.7%; 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 13.3 billion and $US 17.9 billion in obesity costs over 10 years for a 20% and 30% tax, respectively. Study limitations include using a quantile distribution method to adjust self-reported baseline weight and height, which could be insufficient to correct for reporting bias; also, weight, height, and physical activity were assumed to be steady over time. Conclusions: Adding a 20% to 30% excise tax on top of Brazil's current federal tax could help to 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. Using the context of the proposed Sugar-Sweetened-Beverages tax in Brazil, Ana Basto-Abreu and colleagues model the estimated reduction in obesity prevalence and savings in health-related costs. Author summary: Why was this study done?: The consumption of sugar-sweetened beverages (SSBs) is associated with obesity, metabolic diseases, and incremental healthcare costs. The World Health Organization (WHO) recommends governments to tax SSB to improve diet and reduce chronic diseases. Since 2022, a bill to impose a 20% tax on SSB is under discussion in the Brazilian Senate. What did the researchers do and find?: We estimated SSB own- and cross-price elasticities by socioeconomic status and simulated the potential effects of introducing a 20% excise tax to SSB in consumption. If a 20% tax is introduced, we would expect a 16.9 kcal/day/person caloric reduction among Brazilian adults. We used an individual dynamic weight change model to translate caloric reductions into obesity reductions. We estimated an expected 6.7% reduction in obesity, which could lead to USD 13.3 billion healthcare cost savings over 10 years. Larger benefits of the tax are expected to be experienced by younger adults and by people from high-income groups. What do these findings mean?: The implementation of the SSB tax is expected to produce important reductions in population weight and obesity prevalence, while saving health-related costs. Limitations of our analysis include assuming no change in weight under the no-intervention scenario and using a quantile distribution method to adjust self-reported baseline weight and height. [ABSTRACT FROM AUTHOR]