- Warning labels detailing health risks associated with sugary drinks such as diabetes and obesity may convince parents not to buy these beverages for their kids, a U.S. study suggests.

For the experiment, researchers gave 2,381 parents online surveys asking them to select a beverage for their child from a range of 12 sugar-sweetened sodas and juices as well as eight low-sugar options like water, unsweetened juices and diet sodas.

When pictures of the sugar-sweetened drinks appeared, parents were randomly shown warning labels, calorie icons or no health information on the front of the containers.

Absent any health information, 60 percent of parents picked a sugary drink. But with warning labels, just 40 percent of parents chose sweetened beverages.

"We were surprised at how large the effect was," said lead study author Christina Roberto of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.

"Interestingly, calorie labels displayed on the beverages - which is what the beverage industry is currently doing - did not significantly influence parents' choices," Roberto added by email.

Two-thirds of U.S. children aged two to 11 years old drink at least one sugary drink a day, a habit that is linked to the risk of weight gain and obesity in adulthood, as well as cavities.

Part of the problem is that even when parents understand that sodas might be unhealthy, they still don't grasp that many sports drinks, juices and teas can also contain lots of added sugars, Roberto and colleagues note in the journal Pediatrics.

The study findings suggest that labels may be one way to discourage consumption of sugary drinks, though more research is needed to see how warnings work on consumers in the real world, the researchers conclude.

Lawmakers in New York and California are considering bills to require warning labels on sugar-sweetened beverages that are similar to tobacco warnings on cigarette boxes.

To assess the potential of labels to deter sweetened drink purchases, Roberto and colleagues showed some parents in the online survey one of four labels, with slight variations in wording to emphasize different risks such as obesity and diabetes.

One matched the label currently being considered in California: "SAFETY WARNING: Drinking beverages with added sugar(s) contributes to obesity, diabetes and tooth decay."

Another label tweaked this wording to focus on prevention: "SAFETY WARNING: Drinking beverages with added sugar(s) contributes to preventable diseases like obesity, diabetes and tooth decay."

Results didn't differ significantly based on the slight variations in the wording on the warning labels, the study found.

Parents' education level also didn't influence which beverage they selected for their child in the experiment.

Aside from the difficulty of mimicking real-world behavior in an online survey, another limitation of the study is that it didn't measure the impact of the size of warnings or package design, the authors note.

In the real world, for example, parents may not focus as much on warning labels because they have to contend with children clamoring for sugary drinks in the grocery store aisles and yelling when they don't get their way, noted David Studdert, a health law researcher at Stanford University in California who wasn't involved in the study.

"We don't know how the findings would translate into an actual retail environment," Studdert said by email. "They almost certainly represent an upper bound on what might be possible, but the study suggests it would be worthwhile trying to find out."

Most parents do want to make healthy choices for their children, however, and labels that make it easy to decipher which options are better may help influence shopping habits, said Julia Wolfson, a health policy researcher at Johns Hopkins University in Baltimore who wasn't involved in the study.

"Reduced consumption of sugary beverages among children and adults alike could be extremely beneficial for efforts to reduce obesity rates as these beverages are still widely consumed and are a primary source of added sugars and extra calories in Americans' diets," Wolfson said by email.