Using color-coded labels to mark healthier foods and then displaying them more prominently appears to have prompted customers to make more healthful long-term dining choices in their large hospital cafeteria, according to a report from Harvard-affiliated Massachusetts General Hospital (MGH). Previously reported changes have continued up to two years after the labeling intervention was introduced.
“Our current results show that the significant changes in the purchase patterns of both hospital employees and all customers resulting from the labels and the choice architecture program did not fade away as cafeteria patrons became used to them,”
”This is good evidence that these changes in healthy choices persist over time.”
The first phase involved the application of “traffic light” labels — green for the healthiest items, such as fruits, vegetables, and lean sources of protein; yellow for less healthy items; and red for those with little or no nutritional value — to all items in the main hospital cafeteria. Several weeks before the labels were introduced, cafeteria cash registers began to identify and record each purchased item as red, yellow, or green.
The current study analyzed purchase patterns for the 24 months following the program’s implementation and found that the changes present at the end of the first year were virtually unchanged at the end of the second. Overall, purchases of “green” items had increased 12% , compared with the pre-intervention period, and “red” item purchases dropped 20%. Purchases of “red” beverages — primarily sugar-sweetened beverages — dropped 39%, while “green” beverage purchases increased 10%. The changes remained similar for all types of employees, and overall cafeteria sales during the two-year period were stable.