The role of colour and summary indicators in influencing front-of-pack food label effectiveness across seven countries.

objectiveMany countries are considering the implementation of front-of-pack nutrition labels as a strategy to address high and increasing levels of overweight and obesity. A growing body of work demonstrates the superiority of labels that use colour and/or provide a summary indicator of product healthiness to enhance comprehension. However, previous studies have been confounded in determining the relative effectiveness of these two attributes by comparing labels that also differ in other ways. The present study tested labels that varied only on use of colour and/or reliance on a summary indicator across an international sample to provide unique insights into the relative importance of these attributes.

designParticipants were randomised to see one of four variations of the Health Star Rating label that differed on the basis of use of colour and sole provision of a summary indicator.

settingAustralia, Canada, China, India, New Zealand, the UK and the USA.

participantsAdults (n 7545) in seven countries were exposed to online choice tasks requiring them to select a preferred breakfast cereal and then nominate the healthiest cereal.

resultsOverall, the coloured versions, and particularly the one with just a summary indicator, outperformed the monochrome version that included nutrient-specific information. However, there were some differences by country, with results from Canada and China indicating superior outcomes for monochrome labels and those providing nutrient-specific information.

conclusionsThe results highlight the importance of colour, but suggest that the introduction of front-of-pack nutrition labels should be preceded by country-specific formative testing to identify potential differences in outcomes.