New research conducted at Massachusetts General Hospital (MGH) revealed that foods labeled with green “traffic light” symbols helped employees make healthier food choices.
Green labeling on foods indicated a healthier selection, while foods labeled with yellow labels signified less healthy, and red labels were the least healthy. Labeling was based on positive and negative criteria, including whether the main ingredient was fruit, vegetable, whole grain, and so forth, and the amount of saturated fat.
Researchers used employee ID numbers to track the purchases of 5,695 employees buying food at MGH cafeterias. After establishing a three-month baseline period, the team tracked purchases made after the labels were added and again after product-placement changes made healthier choices more accessible. The interventions remained in place at MGH cafeterias, and the study analyzed data over two years after the traffic-light labels were first introduced.
The researchers found that the proportion of green-labeled foods purchased increased, while the proportion of the least healthy foods purchased decreased.
For employees who visited the cafeterias most frequently, the estimated reduction in calories equated to a weight loss of up to 4.4 pounds over time.