A Randomized Controlled Trial Testing the Effects of Singapore’s Front-of-Pack Healthier Choice Symbol Label With or Without a Physical Activity Equivalent Label on Food Purchases and Measures of Diet Quality
Abstract Background Singapore’s front-of-pack (FOP) Healthier Choice Symbol (HCS) label is an easy to understand signal to consumers of how they can make a healthier choice within a given food category. We assess its effectiveness at influencing food purchases and diet quality.Methods Randomized controlled trial using a 3×3 within-subject crossover design with adult Singapore residents recruited online. Each participant shopped once in three conditions on an experimental online grocery store in random order: 1) no FOP control; 2) Similar to Arm 1 except select products displayed HCSs, as would occur in stores in Singapore; 3) Similar to Arm 2 with additional information displaying Physical Activity Equivalents (PAEs) per serving of each product. Participants with minimum of one control and one intervention condition shop were analyzed. First-differenced regressions on calories per serving (primary) and other measures of diet quality were used to compare purchasing behavior across conditions. Results From January 2019 to April 2019, 117 participants were randomized: 10 (8·5%) completed one shop; 2 completed two shops (1.7%); and 105 (89·7%) completed all three, resulting in 317 unique shops. The HCS, without PAEs, led to a statistically significant five-percentage point increase in the proportion of HCS products purchased. However, we could not reject the null hypothesis of no difference in calories per serving in either HCS (95% CI, -10·63: 20·01) or when combined with PAEs (95% CI, -5·25: 21·54) or differences in any of the diet quality measures assessed.Conclusions The HCS influences purchasing patterns, but does not, either alone or in combination with a PAE label, appear to reduce caloric intake or improve overall diet quality. These findings suggest that the HCS label, as currently applied, may be the wrong label for addressing rising rates of obesity and non-communicable diseases in Singapore.