OBJECTIVES

Overconsumption of sugar leads to health issues such as obesity, cardiovascular diseases, and diabetes, and also increases healthcare costs. Sugary drink taxes have been implemented to curb sugar intake in several countries. A previous Canadian model by Jones et al. also showed that it could improve health. However, there is a concern that sugary drink taxes are regressive. This project assessed the impacts of a sugary drink tax by different income groups in Canada.

METHODS

The existing multi-state life table model by Jones was extended to consider impacts on different income groups. The model compared a 20% sugary drink tax scenario with “business as usual” scenario. The changes in beverage consumption and BMI were modelled and further affected relative risks, incidence and prevalence of 19 obesity-related diseases. Data on cross- and own-price elasticities, BMI, and sugary drink consumption were stratified by income quintile.

RESULTS

The consumption of sugary drinks was estimated to be reduced by 14.69% to 15.41%, with the smallest change in the middle-income quintile and the largest change in the lowest income quintile. BMI was estimated to be reduced by 0.21 to 0.33 units, with the greatest reductions predicted in the lowest income quintile. The total disability-adjusted life years (DALYs) averted over 25 years increased with income, from 49,637 for the lowest income quintile to 59,103 for the highest income quintile. Tax revenue in the first year was estimated to vary by income quintile: $209m, $227m, $204m for the lowest, the middle-, and the highest income quintiles, respectively.

CONCLUSIONS

The model predicts that high-income Canadians would gain the most health from a sugary drink tax, while the lowest-income Canadians would pay the largest proportion of their incomes in tax. If this regressivity is a concern, policymakers may consider investing the revenue in policies that reduce health and/or income inequities.