A Randomized Controlled Trial Testing the Effects of A Positive Front-of-Pack Label With or Without a Physical Activity Equivalent Label on Food Purchases.

Abstract Background Positive front-of-pack (FOP) labels are intended to help shoppers identify healthier products. However, there is a lack of evidence on the effectiveness of these labels on actual purchases. We assess the effectiveness of one positive FOP label, Singapore’s Healthier Choice Symbol (HCSs), on food purchases and diet quality with and without added calorie information using a Physical Activity Equivalent (PAE) label. Methods We conducted a randomized controlled trial using a 3 arm within-subject crossover design in adult Singapore residents who were recruited online. Participants were expected to shop once in each condition on an experimental online grocery store in random order: 1) no FOP label (Control); 2) Select products displaying HCS labels (HCS-only); 3) Condition 2 with additional information displaying PAEs per serving on every product (HCS+PAE). In total, 117 participants were recruited and data from 107 shops were analyzed. We used first-differenced regressions to assess the impact of the conditions on calories per serving (primary) and on other measures of diet quality. Results The HCS-only condition led to a statistically significant five-percentage point increase in the proportion of HCS products purchased (95% CI, 1%: 9%). However, neither the HCS-only (3.45; 95% CI, -12.52: 19.43) nor HCS+PAE (8.14; 95% CI, -5.25: 21.54) condition led to a change in the number of calories per serving purchased or changes in other measures of diet quality. Conclusions Positive labels, like the HCS, are likely to increase purchases of labelled products. However, these changes may not lead to improvements in diet quality or calorie intake. Combining positive labels with additional PAE information does not appear to address this concern.