Labeling hospital cafeteria food with red, green and yellow symbols — reminiscent of a traffic light — to indicate their relative healthiness can help individuals consume fewer calories, according to a study published in JAMA Network Open.
For the study, researchers at Boston-based Massachusetts General Hospital placed green labels next to its cafeterias' healthiest foods, yellow labels next to less healthy foods and red labels next to the unhealthiest foods. They then used employee ID numbers to track 5,695 staff members' food purchases for three months before and two years after implementation of the labeling system.
Researchers found the labels were linked to a drop in calories purchased by employees. The biggest decrease was seen among purchases of foods with red labels.
"So that indicates that not only were employees consuming fewer calories at work, but also that they were improving the quality of the calories they were purchasing," lead study author Anne N. Thorndike, MD, an internist and researcher at MGH, said in a press release.