Background
Many countries have sought to incentivise soft drinks manufacturers to reduce sugar in their products as part of efforts to address a growing prevalence of obesity. Are their policies effective?

Methods
Using a difference-in-differences design, we compared trends in the sugar content of 10 695 new sugar-sweetened beverages (SSB) launched between 2010 and 2019 in six European markets, including the UK and France (taxes designed to incentivise reformulation), the Netherlands (policy based on voluntary agreements to reduce sugar), Germany, Italy and Spain (no national policies).

Results
The announcement in 2016 and adoption in 2018 of the UK tax led to yearly reductions in average sugar content of 17% (95% CI: 15–19%) to 31% (13–48%) between 2016 and 2019, compared to 2015, while the 2018 French tax produced a 6% (95% CI: 5–7%) sugar reduction only in 2018, compared to 2017, shortly after it was redesigned to provide a stronger incentive for reformulation. Voluntary agreements implemented in the Netherlands in 2014 led to an 8% (95% CI: 4–13%) sugar reduction only in 2015, compared to 2013.

Conclusion
The analysis supports the conclusions that sugar reductions in new SSBs have been greater in countries that have adopted specific policies to encourage them; a sugar-based tax design encourages more sugar reductions than a volume-based tax design; the tax rate and the amount of the tax reduction from switching to the next lower tier in a sugar-based tax design may be critical to incentivize reformulation.