How helpful are warning labels on sugary drinks?

Warning labels may deter people from buying sugar-laden drinks, finds a study.

Sweetened drinks are a major source of added sugar in one's diet and there is growing concern about the health effects linked with high consumption of the same, such as type 2 diabetes, tooth decay, and cardiovascular disease. Many harmful products already carry warnings.

Whether or not sugar-sweetened drinks should also display warning labels is hotly debated, and which labels might have the greatest impact is unclear.

To investigate this further, Professor Anna Peeters from Australia's Deakin University and colleagues conducted an online choice experiment to examine the drink choices of almost 1000 Australians aged 18-35 years.

Participants were asked to imagine they were entering a shop, cafe, or approaching a vending machine to purchase a drink. They were randomised to one of five groups and asked to choose one of 15 drinks, with sugary and non-sweetened options available.

The drinks included either a no label (control group) or one of four labels on sugary drinks--a graphic warning, text warning, or sugar information, including the number of teaspoons of added sugar; or a health star rating on all drinks. Alternatively, they could select "no drink" if they no longer wanted to buy a drink.

Overall, participants were far less likely to select a sugary drink when a front-of-pack label was displayed compared to no label, regardless of their level of education, age, and socioeconomic background.

Graphic warning labels which indicated that consuming drinks with added sugar may contribute to tooth decay (that include an image of decayed teeth), type 2 diabetes, or obesity appeared to have the greatest impact.

Participants were 36 percent less likely to purchase sugary drinks that included a graphic warning compared to a drink with no label.

"The question now is what kind of impact these labels could have on the obesity epidemic. While no single measure will reverse the obesity crisis, given that the largest source of added sugars in our diet comes from sugar-sweetened drinks, there is a compelling case for the introduction of front-of-pack labels on sugary drinks worldwide," Professor Peeters said.

The study was presented at the European Congress on Obesity (ECO) in Vienna, Austria.