Labeling Food With 'Stop' or 'Go' Colors Might Spur Healthier Diet

Hospitals might be able to coax cafeteria customers to buy healthier food by adjusting item displays to have traffic light-style green, yellow and red labels based on their level of nutrition, new research suggests.

"Our current results show that the significant changes in the purchase patterns ... did not fade away as cafeteria patrons became used to them," study lead author Dr. Anne Thorndike, of the division of general medicine at Massachusetts General Hospital in Boston, said in a hospital news release. "This is good evidence that these changes in healthy choices persist over time."

As part of the study, labels -- green, yellow or red -- appeared on all foods in the main hospital cafeteria. Fruits, vegetables and lean sources of protein got green labels, while red ones appeared on junk food.

The cafeteria also underwent a redesign to display healthier food products in locations -- such as at eye level -- that were more likely to draw the attention of customers.

The study showed that the changes appeared to produce more purchases of healthy items and fewer of unhealthy items -- especially beverages. Green-labeled items sold at a 12 percent higher rate compared to before the program, and sales of red-labeled items dropped by 20 percent during the two-year study. Sales of the unhealthiest beverages fell by 39 percent.

"These findings are the most important of our research thus far because they show a food-labeling and product-placement intervention can promote healthy choices that persist over the long term, with no evidence of 'label fatigue,'" said Thorndike, an assistant professor of medicine at Harvard Medical School.

"The next steps will be to develop even more effective ways to promote healthy choices through the food-service environment and translate these strategies to other worksite, institutional or retail settings," she said.

The study was published in the current issue of the American Journal of Preventive Medicine.

More information

For more about nutrition, visit the U.S. National Library of Medicine.