Perceived healthiness of food items and the traffic light front of pack nutrition labelling: choice-based conjoint analysis and cross-sectional survey.

BACKGROUND

Although traffic light labelling (TLL) is designed to aid the selection of healthier choices, consumers often have to make trade-offs between (un)desirable attributes. With the current emphasis of public health on sugar reduction, the present study aimed to investigate the relative influence of sugar on the perceived healthiness of products.

METHODS

A choice-based conjoint analysis (CBC) survey was designed to assess the relative importance of the macronutrients commonly used in TLL, as well as the rescaled utilities of three attribute levels (red, amber and green), which involved 858 participants aged ≥18 years, who were recruited from the general population of Nottingham. An additional cross-sectional online survey was completed by another 901 participants to assess public knowledge about the intake recommendations underpinning the TLL.

RESULTS

Usable data for CBC analysis showed that, when deciding upon the healthiness of items, sugar was significantly the most important macronutrient (mean 0.34, 95% confidence interval = 0.32-0.35) among the 641 participants. Red labelling was significantly more influential than green across macronutrients. In the substudy, 13.3% of participants correctly identify the maximum recommended intake of free sugars. Moreover, 42.8% of the total sample could not identify whether the sugar information on TLL refers to the total or free sugar content.

CONCLUSIONS

Despite a lack of knowledge about the recommendations underpinning the TLL criteria, decisions made by participants concerning the healthfulness of food products were significantly influenced by sugar content. TLL appears to guide consumer beliefs in the absence of deep knowledge. The dominance of sugar in decision making is unsurprising in the current public health climate.