Worldwide, countries are experiencing a nutrition transition towards foods of higher energy density, and a rapid increase in obesity is observed. This is contributing to an increasing burden of chronic disease. There is strong evidence that sugar-sweetened beverage (SSB) intake is causally related to increased body mass. Higher SSB prices are associated with reduced consumption of SSBs.
We used established multi-state life table modelling methods and publicly available data to estimate the potential impact of SSB taxes on health in South Africa, and in Australia.
For South Africa, we estimated that a 20% tax would reduce energy intake by about 36kJ per day, reducing obesity prevalence by 3.8% in men and 2.4% in women. Our 2014 paper generated much debate, and we have since published papers the impact on diabetes (374,000 health-adjusted life years [HALYs] gained over 20 years) and stroke (550,000 HALYs over 20 years). In February this year, Finance Minister Pravin Gordhan announced plans to introduce a tax on SSBs.
For Australia, we estimated that a 20% tax could lead to gains of 168,000 HALYs, a reduction in overall health care expenditure of AUD609 million over the lifetime of the cohort of adult Australians currently alive, and revenue of AUD400 million annually. Following the announcement of a sugar tax in the UK as it did, our paper generated much media interest last April. The third largest political party endorsed a tax, but at the time of writing, we are yet to see further policy action.
In combination with targeted health promotion efforts (lobbying), quantifying the expected impact on of fiscal measures that improve nutrition can help mobilize public opinion. More importantly, the research has informed briefings with policy makers, politicians, and public health organisations, so they can understand the benefits of an SSB tax and potentially support it.