For years, nutrition experts have been searching for what menu “language” most resonates with diners. Researchers at Carnegie Mellon University found that listing calorie counts for meals along with recommended daily caloric limits did nothing to alter eating habits; other research has shown promising results when those numbers were paired with symbols.

Now, researchers at the University of Pennsylvania School of Medicine have shown that using a color-coded system similar to familiar traffic light patterns demonstrated a decrease in the amount of food consumed by customers ordering food online.

Penn Medicine

In the study, published in the Journal of Public Policy & Marketing, 249 participants placed 803 orders from their business cafeteria via an online ordering portal. The menus were divided into those with no caloric information, caloric information, a green-yellow-red traffic light system, and both a caloric and traffic light interface. A red circle indicated a high-calorie item, yellow moderate, and green the fewest calories.

The study found that the traffic symbols worked as well as calorie counts in getting diners to eat 10 percent fewer calories overall than those who had no calorie information available.

While the Food and Drug Administration intends to mandate calorie counts on food delivery services, restaurant menus, and even movie theaters by May 2017, there may come a time when those numbers are supplemented or even replaced by a color system. Researchers at Carnegie Mellon who conducted a similar study in 2015 indicated that the colors might reach consumers who aren’t as adept at crunching numbers.

[h/t ScienceDaily]