Young adults are less likely to buy sugar-sweetened beverages that include health labels, particularly those with graphic warnings about how added sugar can lead to tooth decay, obesity and Type 2 diabetes, according to research presented at this year's European Congress on Obesity (ECO) in Vienna this week.

The research also indicates that individuals are more likely to choose healthier options if there is a Health Star Rating displayed on beverages. The Health Star Rating is the national front-of-pack labeling system in use in Australia and New Zealand.

Surveys indicate that at least half of Americans and a third of Australians drink at least one sugar-sweetened drink every day. Sweetened drinks, such as soft drinks, cordials, sports drinks, energy drinks and sweetened waters, are a major source of added sugar in the diet and there is growing concern about the health effects linked with high consumption 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 recruited using online platforms and represented a diverse range of socioeconomic status and education levels.

Participants were asked to imagine they were entering a shop, café, or approaching a vending machine to purchase a drink. They were randomized 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.

Other front-of-pack labels were also effective with participants 20 percent less likely to purchase sugary drinks that included the Health Star Rating, or 18 percent less likely for a label displaying teaspoons of added sugar. Furthermore, participants were far (20 percent) more likely to choose healthier alternatives when Health Star Ratings were displayed compared to no label.

"Our findings highlight the potential of front-of-pack health labels, particularly graphic images and Health Star Ratings, to change consumer behavior, reduce purchases of sugar-sweetened drinks and help people to make healthier choices," Professor Peeters said.

The researchers point out some limitations of the study, including that the study measured intended selections of drinks in an online setting, and that the labels would need to be tested on real-world purchases of sugary drinks. They also note that it would be important to test drink labels with adolescents as they are the highest consumers of sugary drinks in Australia.