Designing helpful food labels: a randomized trial comparing effects of Physical Activity Calorie Equivalent and Health Star Rating labels on product perception and choice.

BACKGROUND

Front-of-pack labelling could help consumers choose healthier options over energy-dense, nutrient-poor alternatives.

PURPOSE: We assessed the effects of Health Star Rating (HSRs) and Physical Activity Calorie Equivalent (PACE) labels on adults' food and beverage choices and explored possible mechanisms by which these 2 labelling systems may have their effects.

METHODS

In an online experiment, 1268 Australian adults (18-59 years) were randomized to: no labels (control), PACE, or HSR labels. Participants were shown snack and drink options with varying energy content and nutritional profiles. Participants rated the healthiness and energy content of each product, completed a choice task, and rated both labelling systems in relation to their effects on motivation, emotional responses and perceived label credibility.

RESULTS

Compared to no labels, both HSR and PACE labels increased identification of unhealthy products, while only HSRs increased identification of healthy products. PACE labels prompted more accurate perceptions of energy content for high- and low-energy products compared to HSR labels and no labels. Both PACE and HSR labels prompted a greater proportion of healthy choices, but only PACE labels prompted a greater proportion of "optimal" that is, low-energy and healthy choices. Participants in the PACE condition were more motivated to reduce daily energy intake and take more exercise. Label-induced motivation mediated the effects of labels on optimal product choice.

CONCLUSIONS

PACE labels were most effective in prompting accurate perceptions of the energy content of products and in facilitating optimal (healthy and low-energy) choices. Mediation analyses suggested that this may be due to greater behavior-change motivation generated by PACE labels.