Poor diet is a key risk factor for non-communicable diseases, but sugar taxes can be used to boost population health  

In 2017, more than 950,000 deaths and over 16 million DALYs (a measure of years of life lost and disability caused by ill health) were caused by diseases associated with unhealthy diets in the European Union alone.  

A recent report by the European Commission showed that in 2017 in Portugal, adult obesity was in line with the EU average at 15.4 per cent. However, it also reported that rates among teenagers were growing, with nearly one in five 15-year-olds either overweight or obese in 2013–14. 

Imperial College Business School’s Professor Marisa Miraldo, along with a team of researchers, including Imperial PhD student Dr Francisco Goiana da Silva, worked in collaboration with Portugal’s Ministry of Health to develop several pieces of research on how to promote healthier diets. 

This included an assessment of taxes on sugar sweetened beverages, which showed a clear reduction in the amount of sugar consumed. The decline was greater than the reduction associated with educational policies and industry self-regulation initiatives. 

The effect was larger in the higher tax tier and suggested the government should amend the policy by creating an additional tier, targeting the products with higher sugar content to further reduce consumption and encourage product reformulation. The additional tier was later adopted when Dr Goiana da Silva joined the government task force. 

The team also modelled the impact of this policy on population health and found that it was projected to have prevented around 40–78 cases of obesity per year between 2016 and 2018. The biggest projected impact was observed in adolescents aged between 10 and 18, which is four to eight times larger than would have been achieved through product reformulation alone.