Making sweet drinks more expensive cuts consumption by up to 47%, according to University of Washington (UW) researchers in the United States.
This could in turn help to reduce levels of obesity and diabetes.
The team looked at the effect of taxes on “sweetened beverages” in Seattle, San Francisco, Oakland and Philadelphia, four of eight American cities that have recently imposed measures aimed at curbing intake of the drinks.
“Lower-income households decreased their purchases of sweetened beverages by nearly 50%, while higher-income households reduced purchases by 18%,” the team said, in findings published by the journal Health Economics.
Dozens of countries and local authorities have imposed levies to make sweet drinks more expensive, saying the measures are aimed at curbing the ill-effects of so-called lifestyle diseases such as diabetes.
The International Diabetes Federation estimates over 500 million adults – one in 10 worldwide – have diabetes, warning that the number could grow to over 740 million by mid-century.
The UW team described the measures as “an important policy response to growing obesity rates and the prevalence of type 2 diabetes”.
The drinks “have all kinds of health consequences and don’t really provide any nutrition,” said study co-author and UW associate teaching professor in economics Dr Melissa Knox.
Dr Knox and her colleagues tracked how 400 households shopped for two years – before and after the imposition of the taxes in their cities.
Their work followed previous UW research linking the Seattle tax with reduced body mass index (BMI) among children in the city.
“Together, this body of work suggests the tax is having the intended health benefits and this new evidence gives reason to believe health benefits could be larger for households with lower incomes,” said study co-author and UW professor of health systems and population health Dr Jessica Jones-Smith. – dpa