Background: People substantially underestimate the energy content of fast food meals.
Aim: To test whether the addition of Health Star Rating (HSR) labelling to kilojoule (kJ) labelling on menus at fast food outlets would prompt consumers to select meals with fewer kJs.
Methods: A between-subjects experimental design, whereby 1,007 NSW adults aged 18-49 were allocated to one of four menu labelling conditions: (i) no labelling; (ii) kJ labelling; (iii) HSR labelling; and (iv) kJ + HSR labelling. Using an online methodology, respondents were presented with their menu boards and instructed to select an evening meal as they would at a fast food restaurant. Programming required participants to select at least one item overall, and up to five mains and sides, two drinks and three desserts. A one-way ANOVA, with Bonferroni adjustment, was conducted to test for differences in the total mean kJ content of respondents’ evening meal selections by menu labelling condition.
Results: Overall, the mean kJ content of meals selected did not differ significantly by menu labelling condition (p>0.05). This was consistent across demographic characteristics, BMI, perceived weight status, usual frequency of eating at fast food restaurants, and self-reported importance of nutrition when eating out. However, among respondents who reported using menu board nutrition information to assist meal selection (n=343, 34%), mean kJ content of meals differed significantly by condition (p=0.034). Respondents shown kJ + HSR menu labelling selected meals with a significantly lower kJ content compared to those shown HSR labelling only (4751 kJ cf. 5745 kJ, p=0.038).
Conclusion: For the sample as a whole, the addition of HSR to kJ labelling on menus did not afford a clear reduction in the mean kJ of meals selected. However, among the minority of respondents who made use of nutrition information, it enabled them to select less energy-dense meals.