Exploiting the Spur of the Moment to Enhance Healthy Consumption: Verbal Prompting to Increase Fruit Choices in a Self-Service Restaurant.

BACKGROUND: People often have good intentions to eat healthily, but these intentions may get overruled by temporary moments of temptation. The current study examined the effectiveness of "verbal prompting" as a nudge to increase fruit salad sales in a natural setting.
METHODS: A field experiment was conducted in a self-service restaurant during breakfast time. After an initial baseline period, the intervention involved four different prompts suggesting ordering a side dish (i.e. orange juice, fruit salad, pancakes) given by cashiers to visitors. The intervention phase lasted 13 weeks. Cash register and observational data were obtained. In addition, a sample of visitors (N = 393) responded to a survey.
RESULTS: A significant increase in sales of orange juice was observed during the orange juice verbal prompts intervention periods (35-42% of all breakfasts sold) compared to baseline (20% of all breakfasts sold). Similarly, sales of fruit salad (9%) and pancakes (3%) rose to a small but significant extent compared to baseline sales (3% and 1%, respectively). Survey results showed that customers did not feel pressurised into purchasing a side dish.
CONCLUSION: Together, findings suggest that verbal prompts involving healthy side dishes are a potential useful nudge to implement in other food service settings.