The impact of adding front-of-package sodium content labels to grocery products: an experimental study

Canadians consume approximately twice the daily Adequate Intake of sodium. The present study examined the efficacy of four types of front-of-package (FOP) sodium labels at influencing consumers' selection of products low v. high in sodium.

Participants were randomly assigned to one of five experimental conditions: (i) control condition with no FOP label; (ii) basic numeric FOP label; (iii) numeric FOP label with 'high' and 'low' sodium content descriptors; (iv) detailed Traffic Light (TL) label with colour coding, content descriptors and numeric information; and (v) simple TL label with no numeric information. Participants were shown pairs of grocery products that varied in sodium content and told they could choose a free sample. Selection of the low-sodium v. the high-sodium product was the primary behavioural outcome, in addition to ratings of effectiveness, understanding, liking and believability.

Waterloo, Ontario, Canada.

Adults (n 430) aged ≥18 years, recruited from community settings.

Participants in the three FOP conditions with 'high/low' sodium content descriptors were significantly more likely to choose the lower-sodium product compared with the control group. The detailed TL label was ranked most effective at helping participants select low-sodium products, and was rated significantly higher than other formats in liking, understanding and believability. Product selection did not differ significantly across sociodemographic groups.

FOP labels that include content descriptors may be more effective in helping consumers to select lower-sodium products. TL labels, which incorporate content descriptors and colour coding, should be considered for future FOP labelling initiatives.