Graphic images speak to consumers of sugary drinks
warning labels that include photos linking consumption of sugary drinks to obesity, Type 2 diabetes, and tooth decay may reduce purchases of the drinks, according to a new study by researchers from Harvard T.H. Chan School of Public Health and Harvard Business School. In a field study conducted in a hospital cafeteria, researchers found that graphic warning labels reduced sugary beverage purchases by 14.8 percent, while text warning labels and calorie labels had no effect.
“Warning labels have been around a long time for tobacco products, but they’re a new concept for sugary drinks,” said study co-lead author Grant Donnelly, assistant professor of marketing at Ohio State University and a former doctoral student at Harvard Business School. “Text warning labels have been passed in San Francisco and are being considered in many jurisdictions in the U.S. and around the world. Ours is the first study to evaluate the effectiveness of sugary drink warning labels.”
The study was published online Monday in Psychological Science.
Researchers tested three different labels — one with text warnings about the health risks of sugary drinks, one with graphics warnings, and one with calorie listings — which they displayed near bottled and fountain beverages in a hospital cafeteria in Massachusetts. The labels were tested consecutively, with two-week “washout” periods between each test during which no label was displayed. More than 20,000 beverage sales were recorded during the study.