The impact of the tax on sweetened beverages: a systematic review

Background: Obesity has a serious impact on public health. Sugar-sweetened beverages (SSBs) are implicated in the obesity epidemic. Regulation has been suggested as one approach to limit consumption. Objective: The aim of this study was to synthesize existing evidence related to the impact of taxes on the consumption, purchase, or sales of SSBs. Design: A systematic review was conducted by using MEDLINE through PubMed (https://www.ncbi.nlm.nih.gov/pubmed), the Cochrane Library (http://www.cochranelibrary.com/), the Web of Science (https://login.webofknowledge.com/error/Error? PathInfo=%2F&Error=IPError), and Scopus (https://www.scopus.com/search/form.uri?display=basic) in the period 2011-2017 for studies that analyzed the impact of fiscal regulatory measures on the consumption, purchase, or sales of SSBs. The quality of evidence was assessed according to the CONSORT (Consolidated Standards of Reporting Trials) and the TREND (Transparent Reporting of Evaluations with Nonrandomized Designs) statements. Results: Of the 17 studies, 5 (29.4%) evaluated the impact of a tax on SSBs in naturalistic experiments by county or city in the United States and in Mexico. Findings indicated that purchases or sales of SSBs decreased significantly with taxation amounts of 8% (Berkeley, CA) and 10% (Mexico). One study found no effect on sales of SSBs in 2 states that enacted a 5.5% tax on sodas. Twelve (70.6%) studies were based on virtual or experimental conditions evaluating either purchasing behavior or sales (6 studies; 50.0%) or behavioral intent (6 studies; 50.0%), resulting in a decrease in either purchasing behavior or sales or intent behavior with heterogeneity according to the tax rate. Conclusions: Taxation significantly influences planned purchases and increases the probability of the purchase of healthy beverages. SSB taxes have the potential to reduce calorie and sugar intake, but further research is needed to evaluate effects on diet quality.