What Makes a Front-of-Pack Nutritional Labelling System Effective: The Impact of Key Design Components on Food Purchases

Abstract

The relative impacts on food purchases of many alternative front-of-pack nutritional labelling systems were tested, with various methods-from opinion pool to nationwide experiments. Clearly, some systems induce better purchasing responses, having better nutritional impacts on food baskets. Nonetheless, we still ignore what the ingredients of an efficient label are. Here, we propose guidance for label designers. To do so, we first propose a typology that breaks down established labelling systems into four elementary components: Directiveness, Scope and Gradation, Set of Reference and Sign. On this basis, we then build seven alternative generic labelling systems that we test in a framed-field experiment enabling us to measure the effect of each component on food purchases in isolation. Our results show that an effective front-of-pack labelling system should be Food-Directive (instead of Diet-Directive) and be displayed on both healthy and unhealthy food. The reference set, which is across categories or within categories, produces the same average nutrition score but generates contrasting behavioural responses.

Keywords: food labelling; food purchases; framed field experiment; labelling typology; nutrition; policy.

Figure A1

Nutrition Information Panel (Australia) provides information on the average amount of energy (in kilojoules or both in kilojoules and kilocalories), protein, fat, saturated fat, carbohydrate, sugars and sodium in the food, as well as any other claim that requires nutrition information. The nutrition information must be presented in a standard format which shows the average amount per serve and per 100 g (or 100 mL, if liquid) of the food. Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers.

Figure A2

Facts-Up-Front (USA) provides the energy content alone or together with saturated fat, sugars, and sodium per serving. It can also include information on up to two nutrients to encourage. Daily values are provided for all nutrients except sugar. Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers.

Figure A3

Reference Intake Label (EU) provides the energy content in both kilojoules and kilocalories and the content of four nutrients (sugar, fat, saturated fat and salt) in grams and as a percentage of daily reference intake per serving. Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers.

Figure A4

Daily Intake Guide (Australia) provides the energy content per serving in kilojoules and the content per serving of four nutrients (fat, saturated fat, sugars, and sodium) in (milli)grams and as a percentage of daily reference intake. Additional nutrients are permitted for display such as protein, carbohydrates, vitamins and minerals. Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers.

Figure A5

Multiple Traffic Lights (United Kingdom) was developed by the UK Food Standards Agency (FSA). It supplements traffic light colours (and optionally the adjectives “low”, “medium” and “high”) to the reference intakes for fat, saturated fat, sugars and salt. The colour green is assigned for low contents according to Regulation (EC) No 1924/2006. Red colour if the amount of nutrient per 100 g or 100 mL is more than 25% (12.5% for beverages) of the recommended maximum daily intake for an adult (If the portion size is more than 100 g or 150 mL, the thresholds apply per portion). Directiveness: Diet-Directive; Scope: All food; Gradation: three classes; Set of Reference: Across-Category; Sign: Colours, Numbers and Words.

Figure A6

Nutri-Score (France) is a graphic scale that divides the nutritional score into five classes (expressed by a colour and a letter), based on the food’s content of energy, sugars, saturated fat, sodium, fruit, vegetables, nuts, fibre, and protein per 100 g or 100 mL (Algorithm based on UK Food Standards Agency Nutrient Profiling system with minor modifications for cheese, added fats, and beverages). Developed under the aegis of the French government, Nutri-Score is now in use in Belgium, Spain, Germany, the Netherlands and Luxembourg. Directiveness: Food-Directive; Scope: All food; Gradation: five classes; Set of Reference: Across-Category; Sign: Colours.

Figure A7

Health Star Rating (Australia and New Zealand) attributes a summary score between 0.5 and five stars, from the poorest to best nutrient profile. Using food group-specific conversion keys, the star rating is based on a nutritional score that assigns good and bad points for qualifying and disqualifying nutrients per 100 g. It may be complemented with quantitative energy and nutrient content information, per 100 g, 100 mL, or pack. Directiveness: Food-Directive; Scope: All food; Gradation: 10 classes; Set of Reference: Across-Category; Sign: Numbers, words, ideograms.

Figure A8

KeyHole (Nordic Europe) labels food that contains fewer sugars and salt, more fibre and whole grain and less fat per 100 g or 100 mL than food products of the same food categories. Some food categories are not permitted to carry the logo (e.g., sweet and savoury snacks). Directiveness: Food-Directive; Scope: Recommended food; Gradation: Binary; Set of Reference: Within-Category; Sign: Ideograms

Figure A9

Choices Logo (Poland, Czech Republic) identifies the healthiest options in a given category based on threshold levels for saturated and trans-fatty acids, added sugar, salt, dietary fibre, and/or energy, with category-specific cut-offs per 100 g or 100 mL. Directiveness: Food-Directive; Scope: Recommended food; Gradation: Binary; Set of Reference: Within-Category; Sign: Ideograms.

Figure A10

Heart Symbol (Finland) identifies options with a better nutrient profile in a given category based on threshold levels for energy and various nutrient (fat, salt, sugar and fibre contents depending on the food groups) per 100 g. Directiveness: Food-Directive; Scope: Recommended food; Gradation: Binary; Set of Reference: Within-Category; Sign: Ideograms.

Figure A11

Warning Signs (Chile, Uruguay, Peru) identifies foods high in energy, sugar, sodium, saturated fat or potentially other nutrients that should be consumed less. The reference base is 100 g or 100 mL, or portion depending on the country. Directiveness: Diet-Directive; Scope: Warned food; Gradation: Binary; Set of Reference: Across-Category; Sign: Words, Ideograms.

Figure A12

Nutritional Circles (Germany) provides the energy content in both kilojoules and kilocalories and the content of four nutrients (fat, saturated fat, sugar and salt) in grams and as a percentage of daily reference intake per 100 g or 100 mL. In complement, pie charts represent the amount of energy and nutrients in proportion to the recommended daily amount for an average adult. This scheme is supported by the industry association Federation for Food Law and Food Science (BLL). Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers, ideograms.

Figure A13

NutrInform Battery (Italy) is based on the Reference Intake Label (Figure A3) with an added battery symbol indicating the amounts of energy and nutrients in a single serving as a percentage of the daily intake. Directiveness: Non-Directive; Scope: All food; Gradation: Cardinal; Set of Reference: Across-Category; Sign: Numbers, ideograms.

Figure A14

Subjects’ decision booth with computer, food catalogue, barcode reader and pen and paper.

Figure A15

Food catalogue with no label—Example of one page: the meat category.

Figure A16

Food catalogue with labels – Example of the meat category with the Food-Directive, Within-Category, Recommended (F-W-R) logo system at the top left, Food-Directive, Within-Category, Recommended and Warned (F-W-R&W) at the top right, Diet-Directive, Across-Category, Recommended (D-A-R) at the bottom left and Reference Intake (RI) at the bottom right.

Figure A17

Screenshot.