Research published in the journal PLoS One suggests it can — in a significant way. When scientists at the University of North Carolina (UNC) in Chapel Hill affixed sugary drinks with labels like those on cigarette boxes that warned of diabetes, heart disease, and overall health risks of too much sugar, they found parents were 17 percent less likely to buy soda, juice, and sugar-packed drinks for their kids. “Seventeen percentage points is a pretty big reduction. It’s hard for parents to know if what they’re buying is healthy or not because these products are covered in nutritional claims that are misleading. We found these warning labels helped to cut through that noise and let people know quickly and easily that this isn’t a healthy drink,” says the study’s senior author, Lindsey Smith Taillie, PhD, a UNC assistant professor specializing in food policy to prevent chronic diseases.

Researchers Created a Market-Like Laboratory

For their study, the research team created a “mini-mart” laboratory, stocked with everything you’d see in a typical convenience store, from milk and eggs to toiletries and energy drinks. They also designed front-of-package labels for sugary drinks that had graphic images of heart disease and type 2 diabetes. About 325 parents with kids ages 2 to 12 were recruited in March 2021 for the study — in prior questionnaires, these parents said their kids had consumed at least one sugary drink in the week before. The researchers tasked the parents to buy one drink and one snack for their child, along with a household item to mask the purpose of the study in the mini-mart. The parents were split into two groups: a control arm, which shopped for sugary drinks with “neutral” barcodes on labels, and a study arm, which saw the newly designed labels on all sugary drinks. Turns out, the scary photos and their warnings stopped parents from picking up sugary drinks: While 45 percent of parents who simply saw barcodes on labels chose soda or sugar-sweetened juice, only 28 percent of those who saw the warning labels bought a sugary drink for their kids. In a post-shopping survey, parents said the warning labels were effective in reminding them not to feed their kids sugary drinks and helped them to feel “in control” of making healthy eating decisions. The researchers found the warning labels were effective regardless of race, ethnicity, or socioeconomic status. “We think the paper could be useful for policy makers in the U.S. and globally,” says the study’s lead author, Marissa Hall, PhD, a UNC assistant professor in the Gillings Department of Health Behavior. She notes that since 2011, several U.S. states — California, Vermont, Washington, Hawaii, New York, and Maryland — have proposed legislation requiring sugary drinks to contain warnings on packaging, advertisements, or at the point of sale. Globally, seven countries, including Chile, Mexico, and South Africa, have already passed laws mandating “high in added sugar” warnings on products, along with warnings for sodium levels and unsaturated fats. “What’s really clear is that sugary drinks are uniquely harmful. They provide no nutrition, they’re one of the biggest sources of added sugars, and the other problem is they’re heavily marketed to children and parents. When you’re thinking about where to start in improving nutrition, removing sugary drinks from a child’s diet is a logical place to start,” says Marlene Schwartz, PhD, the director of the Rudd Center for Obesity and Food Policy at the University of Connecticut in Hartford.

Confusion Around Current Labeling and Health Claims

Right now, labels on sugary drinks can be confusing, with health claims and buzzwords like “natural,” “fortified,” or “a great source of vitamin C,” she says. “The research on warning labels is encouraging. When you have a clear message, particularly with images that are pretty shocking, that gets people’s attention and it can make a difference in their behavior,” Dr. Schwartz says. The World Health Organization recommends limiting added sugar intake to less than 10 percent of total calories, while the American Heart Association suggests that kids 2 and older should consume less than 25 grams (g) — or 6.25 teaspoons (tsp) — of added sugar per day, and no more than 8 ounces (oz) of sugary drinks per week. Still, U.S. kids and adolescents report drinking 17 percent of their daily calories from added sugars, nearly half of which are from sugary drinks, according to the AHA. A 12 oz can of Coca-Cola, for example, has 39 grams of sugar.

Signs That a Sugar Tax Can Be Effective

In 2019, the American Academy of Pediatrics and the American Heart Association issued a set of policy recommendations that included a tax on sugary drinks, calling them a “grave health threat to children and adolescents.” Dr. Natalie Muth, MD, MPH, a California-based pediatrician who was the first author of the joint statement, says a sugar tax and warning labels on sugary drinks would pair well to help consumers make better choices. “These strategies absolutely can and should work in tandem to help lower sugar drink consumption,” Dr. Muth says. She says Berkeley, California, and Philadelphia, Pennsylvania, are the “best examples” of jurisdictions that have implemented a sugar tax with growing evidence that the policy has been effective. In Berkeley, the first U.S. municipality to pass an excise tax on sugary drinks in November 2014, consumers pay a one-cent-per-ounce tax on drinks with added sugars, including soda, energy drinks, and coffee drinks. After just three years, the city saw a 52 percent cut in servings of sugary drinks, according to research published in the American Journal of Public Health in April 2019. Water consumption also saw a bump, increasing by 29 percent over the three-year period. Lynn Silver, MD, MPH, a pediatrician in Berkeley, California, and a senior adviser at the Public Health Institute, says multiple “creative” policies need to kick in to change Americans’ health for the better. “There is no single silver bullet to address the epidemic of diabetes and obesity. It’s going to take multiple policies and changes in the environment to really turn this around,” she says. For now, the experts advise parents to think carefully while they’re grocery shopping. “The takeaway is to encourage children to drink water, milk, and other beverages that do not contain any added sugar,” Muth says.