The case against added sugar in beverages has grown so damning that some health advocates and lawmakers have suggested adding a health warning to their packaging the same way we do for alcohol and tobacco products.

“Many of the approaches being used for sugar reduction come straight out of tobacco and alcohol scripts because we have decades and decades of experience with these,” said Laura Schmidt, Ph.D., a professor of Health Policy in the School of Medicine at the University of California at San Francisco.

Sugar in Soda

A study published today in Pediatrics is the first to analyze whether such labeling would work. In a controlled online survey, parents told researchers they would shy away from products with health warnings on them.

The effect was constant regardless of the parents’ socioeconomic status or the specific wording of the label.

Read More: Reducing Sugar in Sodas Would Greatly Reduce Obesity and Diabetes »

Growing Body of Evidence

In recent years, research has revealed that fructose — the form of sugar found in fruits and table sugar — is harder on the body than glucose. However, fruit offers dietary fiber and vitamins that make it healthful.

“The evidence is quite clear that consumption of fructose in whole fruits is heart healthy, whereas fructose in sugary beverages is heart unhealthy,” Schmidt told Healthline. “It has to do with how that sugar winds up in your body and what comes along with it for the ride.” 

Glucose has also been linked to metabolic conditions, such as obesity, fatty liver disease, and type 2 diabetes.

Parents may not track the fine points, but no one has ever thought soda was a health food. Do we really need a label to tell parents that soda is bad for kids?

“Labels don’t just educate consumers,” said Christina Roberto, Ph.D., an assistant professor of medical ethics and health policy at the University of Pennsylvania’s Perelman School of Medicine and the study’s lead author. “They also serve as a reminder. What the label is trying to do is remind you at that critical moment when you’re about to make a decision.”

Two out of three U.S. children between the ages of 2 and 11 drink sugar-sweetened beverages daily, according to a survey cited in Roberto’s research.

Schmidt pointed to the way that sodas are sold in convenience stores and near grocery checkout lines.

“These products are designed to be impulse purchases,” she said. “Even for people who have decided to avoid them, that label can really remind you of why you don’t want to be buying them.”

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Hidden Sugar in ‘Healthy’ Drinks

Even parents who avoid soda may fall for the health claims of sports beverages and drinks that contain some fruit juice along with added sugar.

“It’s not necessarily true that people realize a lot of these other beverages have a lot of sugar,” Roberto told Healthline.

If local, state, or federal regulators begin requiring labels, they will have to decide how much added sugar would trigger the warning and whether products with some nutritional value would be subject to the same requirements.

Roberto’s study did not include sports drinks or sweetened milk products, relying on a California bill as its criteria. It did include juices with added sugar.

Local and state labeling requirements could come to different conclusions about which products other than soda would have to carry the warning label. Soda is an easy target because it has no nutritional benefits to compensate for the health risks it presents.

“Regulation is a blunt instrument and you’ve got to draw the line somewhere,” Schmidt said. “If you could make an argument that there was much to say to the credit of these products then I think it would be different.”

Read More: Some Sodas Are Worse Than Others »

Labels Are Likely

Roberto was surprised to find that nearly 75 percent of survey respondents would support warning labels on sodas and sweetened juice drinks.

That support, along with the evidence that labels affect buying habits, make it likely that U.S. consumers will see health warnings on the sugary drinks soon.

“We’ve hit the tipping point and we’re going to now see this stuff happen more and more — as with any case of expanding innovation, it’s those first cases that really take a lot of the effort,” she said. “The scientific evidence is just too clear at this point, and we just can’t tolerate the healthcare costs the way we are.”