Traffic light colors can help consumers opt for healthier food options, a new study found. Corporate employees chose lower calorie meals when the food items on a website had either numeric calorie labels or a color coding scheme patterned after traffic light colors.
In the study, low-calorie food items were a given green-colored label. Mid-calorie food items were given a yellow-colored label, while the high-calorie options were given a red-colored label.
This resulted in a 10 percent reduction of total calories ordered by the participants compared with menus that featured no numeric or color-coded labels. The findings were released in the Journal of Public Policy & Marketing.
"Calorie labeling appears to be effective in an online environment where consumers have fewer distractions, and the simpler traffic-light labeling seems as effective as standard calorie numbers," said Eric M. VanEpps, Ph.D., the study's lead author and a postdoctoral researcher at the University of Pennsylvania's Perelman School of Medicine.
In the study, VanEpps worked with Carnegie Mellon University colleagues to set up the online food ordering system. The food menu items were presented with numeric or color-coded labels. Some menus were presented with both label types while some with none at all.
The experiment lasted for six weeks. At the end of the study period, the 249 participants placed a total of 803 orders. Findings showed that all three types of food labels — traffic lights, numeric and both together — reduced the total calories ordered by 10 percent compared with the menu that featured no calorie labels.
VanEpps added that the same effects of both labeling types suggested that people are making food choices based on which items appear healthier rather than on the absolute calorie content.
The caloric labels also showed strong impacts among the participants suffering from obesity compared with the non-obese participants.
The researchers added that future studies are needed to look at different food options and sets of study participants. However, the current findings provide a "clear evidence" that color coding and numeric calorie labels can help people choose low-calorie meals when ordering food items via the internet.
The U.S. Food and Drug Administration will implement a numeric calorie labeling system in movie theaters, restaurants, food delivery services and vending machines in 2017.
In the United States, over one-third of American adults are suffering from obesity. The U.S. Centers for Disease Control and Prevention said that obese people spend $1,429 more in medical expenses compared with people with normal weight.