The efficacy of calorie labelling formats on pre-packaged foods: An experimental study among adolescents and young adults in Canada.

OBJECTIVES: Several countries have proposed changes to calorie labelling on nutrition facts tables (NFTs) on pre-packaged foods. As most research to date has examined general use of NFTs, there is a lack of evidence to guide specific design changes to calorie information on labels. This study examined the efficacy of various calorie labelling formats on recall, comprehension, and consumer preferences for calorie information.

METHODS: Experiments were conducted as part of an online survey with a national sample of 2,008 Canadians aged 16-24. In Task 1, participants were shown one of six labelling formats (e.g., %DV, Traffic Light) with calories in either small or large font, and asked to recall the amount of calories. Task 2 examined comprehension of calories in the context of recommended daily intake (RDI), using the same NFT as in Task 1. Task 3 identified participants' preferences for labelling formats.

RESULTS: NFTs with calories in large font enhanced calorie recall (p < 0.001). When small font was displayed, the Traffic Light format performed best at improving recall (p < 0.01). With large font, the highest recall was in the Current, RDI and Traffic Light formats (all p < 0.05). Comprehension of servings per RDI was highest in the Infographic format, with no difference by font size (p < 0.001). Respondents preferred the large font calorie condition and the Infographic format (p < 0.001).

CONCLUSIONS: Enhancements in visibility and design can improve the efficacy of calorie labelling on pre-packaged foods. The findings have direct implication for proposed changes to calorie labelling on NFTs in Canada and the United States.