BACKGROUND

Front-of-package (FOP) nutrition labeling systems differ in how they rate food and beverage products. There is a need to examine the implications of these differences, including their focus on nutrients of public health concern.

OBJECTIVE

Our aim was to examine the impacts of 4 common FOP labels on consumers' purchases of products that received conflicting ratings across FOP systems.

DESIGN

In an experimental marketplace, participants were randomized to complete a series of purchases under 1 of 5 FOP conditions: no label, "high in" nutrient labels, multiple traffic light, Health Star Rating, or a 5-color nutrition grade.

PARTICIPANTS/SETTING: A final sample of 3,584 Canadians (13 years and older) were recruited from shopping centers in March to May 2018.

MAIN OUTCOME MEASURES

Probability of purchasing was assessed for 5 product categories (100% fruit juice, plain milk, chocolate milk, cheese snacks, and diet beverages), which received conflicting ratings across the FOP conditions.

STATISTICAL ANALYSES

Separate generalized linear mixed models estimated the influence of FOP condition on 5 binary outcomes (1 = purchased, 0 = not purchased) corresponding to the product categories.

RESULTS

Few differences were observed among the full sample. Among participants who noticed the labels (n = 1,993), those in the Health Star Rating condition were 4.5 percentage points (95% CI -7.0 to -1.9) more likely to purchase 100% fruit juice (compared to multiple traffic light) and 3.3 (95% CI 0.4 to 6.2) and 3.0 percentage points (95% CI 0.1 to 6.1) more likely to purchase cheese snacks (compared to no label and "high in"). "High in" labels produced fewer purchases of chocolate milk than no label.

CONCLUSIONS

Despite some similarities, existing FOP systems differ in the extent to which they promote or dissuade purchases of common product categories. Although the Health Star Rating might encourage purchases of products with certain positive nutritional attributes, "high in" and multiple traffic light systems might more effectively discourage purchases of products contributing nutrients of public health concern.