Effects of traffic light labelling and increased healthy range on beverage choices from vending machines.

Objective: To test whether traffic light labels and an increased range of healthy beverages, individually and in combination, can increase healthy beverage choices from vending machines.

Design: Two studies ( 558, 420) tested whether the provision of traffic light labels (green, amber and red) and an increased range of healthy beverages (from 20 % to 50 % green options), individually and in combination, could increase healthy beverage choices from a digital vending machine display. The studies used a between-subjects experimental design, and a hypothetical beverage choice, a limitation when considering real-world applicability.

Setting: Both studies utilised an online Qualtrics survey that featured a digital vending machine display.

Participants: Both studies ( 558, 420) consisted of university students from Flinders University and individuals from a survey recruitment service.

Results: Featuring traffic lights did not significantly influence beverage choices ( = 0·074), while increasing the healthy range ( = 0·003, OR = 3·27), and the combination of both, did significantly increase healthier beverage choices ( < 0·001, OR = 4·83).

Conclusions: The results suggest that the traffic light system and increased healthy range are not maximally effective when used on their own, and benefit greatly when combined, to increase healthy beverage choices. It was suggested that the provision of traffic light labels supplied the necessary nutritional information, and the increased healthy range offered greater opportunity to act in accordance with that information. In so doing, the present findings offer a promising pathway for reducing unhealthy beverage consumption.