Testing the Effects of Singapore's Front-of-Pack Healthier Choice Symbol Label With or Without a Physical Activity Equivalent Label

Duke-NUS Graduate Medical School117 enrolled

Overview

Poor diets are known risk factors for chronic diseases, and in recent years, food labelling has been increasingly sought-after as a cost-effective intervention to help stem the rising trend in chronic diseases. In efforts to promote a healthy diet, the Singapore Health Promotion Board (HPB) supplements traditional nutrition labelling with the Healthier Choice Symbol (HCS), which identifies food items within a specific category of foods as healthier choices. The original logos were enhanced to include additional information focusing on particular macronutrients, taking one of two themes; it either indicates that a product contains more of a healthier ingredient, or less of a less healthy ingredient. However, to date, no published studies have assessed the role of the original and enhanced HCS logos in influencing food choices. There is a lack of scientific evidence on the role of the existing symbols in assisting consumers make healthier food purchasing decisions. There are also concerns over the unintended consequences of health claims made based on a single aspect of nutrient content, without considering other aspects. That is the goal of this effort. Specifically, the investigators propose to conduct the following: Use a three arm randomized controlled trial (RCT) and an experimental fully functional web-based grocery store to assess the causal effect of the new HCS logos on measures of diet quality either alone, or in combination with a complementary front-of-package (FOP) label: Physical Activity Equivalents (PAEs), which provides information on how long one would need to engage in a certain activity (e.g., jogging) to burn off one serving of the product. The investigators hypothesize that the greatest reduction in calories per serving (primary outcome) will occur in the HCS plus PAEs arm, followed by HCS only, and no logo control arm.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

HEALTH_SERVICES_RESEARCH

Masking

TRIPLE

Enrollment

Interventions

Healthier Choice SymbolBEHAVIORAL

The HCS is intended to improve diet quality by signaling to consumers which products are healthier options within a specific category (e.g., which are the healthier biscuits or the healthier beverages). Manufacturers must meet category-specific criteria before a product can display the HCS and an associated tagline. The labels were displayed at the bottom of the product images.

Physical Activity Equivalent labelBEHAVIORAL

For the study, we designed a simple PAE logo (Appendix Figure A1) and added a description encoded into the NUSMart user interface to ensure that participants would understand the contents of the label. Participants saw the following description whenever their cursor hovered over the PAE label: "The Physical Activity Equivalent (PAE) refers to the number of minutes that a typical adult would need to jog to burn off the calories associated with one serving of the product." Previous studies have shown this labelling approach to be effective. The labels were displayed at the bottom of the product images.

Outcomes

Primary Outcomes

Change in average calories per serving purchased per shopping trip

Calories per serving (kCal per serving) is calculated by dividing the total number of calories purchased in the shopping trip by the total number of servings purchased. The average calories per serving purchased (kcal per serving) is based on mean standardized serving sizes within each subcategory.