Taxing sugar-sweetened beverages as a policy to reduce overweight and obesity in countries of different income classifications: a systematic review

Objective: To evaluate the potential impact of sugar-sweetened beverage (SSB) taxes on overweight and obesity prevalence in countries of different income classifications. Design: Systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO number CRD42020161612). Five databases (Cochrane Library, Embase, LILACS (via Virtual Health Library) and MEDLINE (via PubMed), and Web of Science were searched, from January 2009 to December 2019. Articles that reported changes in purchases, sales, intake, body weight, BMI, overweight and/or obesity prevalence due to a tax on or price change in SSB were included. Setting: Studies conducted in countries of different income classifications. Participants: The search yielded 8349 articles of which 21 met inclusion criteria. Results: Among the sixteen studies selected, only two did not show that consumption, sales and purchase decreased as the price of SSB increased. In eight of the thirteen studies selected, a positive effect of an SSB tax on decreasing overweight and obesity prevalence was expected. It is estimated that a 20 % taxation on SSB would result in a greater decrease in the prevalence of overweight and obesity compared to a 10 % rate. Studies with no significant effect of taxing on sales, purchases, consumption and prevalence of obesity were from high-income countries, while significant effects of taxing on reducing purchase, consumption and/or obesity prevalence were found in studies from upper-middle- and middle-income countries. Conclusion: A high SSB tax might be an effective fiscal policy to decrease purchase and consumption of SSB and reduce overweight/obesity prevalence, especially if the tax were specific for beverage volume.