In Chile, black warning labels shaped like stop signs are required for certain products
Labelling systems must be based on credible nutrition profiling models
Health warnings on packaged food is an emerging area of interest
Front-of-pack nutrition labelling systems aim to provide standard, clear information on the nutritional content of packaged food items so consumers can readily identify healthier options. The policy objective is two-fold:
- to help consumers make healthier food choices, and
- to encourage industry to reformulate products to create healthier options.1
Front-of-pack nutrition labelling can play an important role in rebalancing unhealthy food environments, as part of a comprehensive strategy to improve healthy choices and reduce normalisation of unhealthy food.2
Front-of-pack nutrition labelling systems have now been implemented in more than 30 countries (where governments have led and supported their development),3 and systems are under consideration or development in many other countries.4 Most nutrition labelling systems introduced to date have been voluntary, although more mandatory systems have been introduced in recent years. The World Cancer Research Fund International recommends that governments consider mandatory implementation of front-of-pack labelling to overcome problems with limited uptake of voluntary systems.4
Nutrition labelling systems
Front-of-pack nutrition labelling systems can be broadly categorised as summary indicators and nutrient-specific systems.
Summary indicators provide an assessment of a food’s overall nutritional quality (for example: four out of five stars; a rank from A-E; or an overall ‘tick’ of approval). These systems are usually based on an algorithm that takes into account a variety of food components (for example nutrients associated with health risks; as well as health benefits such as fruit, vegetable, nut and legume content). Examples include Australia’s Health Star Rating System, France’s Nutri-Score and positive health logos such as Scandinavia’s Keyhole system.
Nutrient-specific systems come in two types:
- Interpretive systems that provide judgment or guidance on a set of nutrients, for example via multiple traffic light symbols or warning labels. Examples include Chile’s system of black warning labels shaped like stop signs for food and drinks that exceed limits for sugar, salt, saturated fat and calories; and the UK’s traffic light system which colours each nutrient as green, orange or red.5
- Reductive systems that show information only, without any judgement or recommendation. Examples include designs that incorporate nutrient amounts and their percentage contribution to daily recommended intakes for an adult male, for example Guideline Daily Amounts in the United States or the Australian Food and Grocery Council’s Daily Intake Guide.1
There is a continually growing body of experimental and real world evidence seeking to examine the effectiveness of different nutrition label formats in a variety of cultural contexts. While nutrition labelling formats vary in their effectiveness,67 there is now clear evidence that consumers cannot easily understand and use reductive systems, which summarise the nutrition information provided on back-of-pack but do not make any judgement or recommendation.8 This is the form of nutrition label typically preferred by industry. Consumers prefer front-of-pack nutrition labels that are interpretive, providing evaluation or judgment of nutritional quality to provide overall guidance (such as four out of five stars, or Chile’s black warning labels).9
Nutrient warning labels
An emerging area of interest is the use of nutrient warning labels on packaged food and drinks. Chile has been a leader in this area after introducing black warning labels shaped like stop signs for packaged food and drinks exceeding limits for sugar, salt, saturated fat or calories in 2016.10 Some products must display multiple nutrient warning labels, which are linked to restrictions on marketing to children and foods for sale in schools. There is preliminary evidence that nutrient warning labels are contributing to a shift in social norms and behaviour;11 and have prompted manufacturers to reformulate products to reduce problem nutrients.5
A randomised controlled trial conducted in a replica convenience store in the US tested the effect of red labels shaped like stop signs on sugar-sweetened beverages with the words: “Warning – beverages with added sugar contribute to tooth decay, diabetes and obesity”.12 The study found that shoppers exposed to the label were less likely to purchase sugar-sweetened beverages and purchased 22% fewer calories (kilojoules) in a basket of goods, compared to a control group. The researchers said that, if sustained, this reduction in energy purchased would have meaningful health benefits at a population level.
Graphic health warnings
There is some evidence that graphic health warnings similar to those used on tobacco products can lead people to make healthier dietary choices. An Australian study found that negatively framed graphic health warnings prompted greater dietary self-control than a range of other health warnings including text-based and positively framed labels.13 Another Australian study showed that front-of-pack labelling had the potential to reduce purchases of sugary drinks, with graphic health warnings showing the largest effect compared to text warnings, information on sugar content, and Health Star Ratings.14 A US study found that graphic health warnings reduced sugary drink purchases in a cafeteria and led customers to purchase water instead.15
Beyond differences in physical label format, front-of-pack nutrition labelling policies worldwide use different nutrient profiling models, or methods of ‘scoring’ foods.16 It is important for front-of-pack labelling systems to be based on a credible nutrient profile model.4
Nutrient profiling is the science of classifying foods according to their nutritional composition for reasons related to preventing disease or promoting health.17 Nutrient profiling is currently used for a variety of applications worldwide, including front-of-pack nutrition labels, as well as regulation of marketing to children, provision of foods in public institutions, and to underpin the use of fiscal policies to promote healthier diets.
In the context of front-of-pack nutrition labelling, two broad types of nutrient profiling are used. Summary indicator systems typically use an algorithm that takes into account a variety of food components to give an overall score – this is the case for Australia’s Health Star Rating System. In contrast, nutrient-specific systems typically use a series of thresholds for particular nutrients to determine whether or not a food should carry the label.
In terms of the nutrients considered, front-of-pack labelling systems focus either on ‘nutrients of concern’ such as saturated fat, sugar and sodium; or weigh both negative and positive nutrients to evaluate the nutritional value of the food as a whole. Most systems implemented across the world to date focus on nutrients of concern due to evidence linking them to diseases caused by poor diet, overweight and obesity.4 Australia’s Health Star Rating System assesses both positive and risk nutrients.
Evidence for front-of-pack nutrition labels
Overall, there is evidence that front-of-pack nutrition labels are effective at drawing consumers’ attention to nutrition information, particularly when labels are colour-coded.18 A US study using eye-tracking technology found that coloured front-of-pack labels increased attention to nutrition information for people who did not have an explicit nutritional goal, suggesting that such labels could help convey nutrition information to a wide segment of the population.19 The US researchers concluded that raising awareness, even to partial nutrition information on the front of pack, was a step towards fostering improved food choices. In light of their findings, they warned that food manufacturers should not be allowed to selectively report nutrition information on the front of packs, since it had the potential to mislead consumers.
A systematic review of consumer use and understanding of nutrition labelling on packaged food, including mandatory back-of-pack nutrient labels, found that consumers perceived nutrition labels as a highly credible source of information.20 Many consumers used nutrition labels to guide their selection of food products, though in some cases reported a desire for simpler presentation of information. The authors said there was a need to balance the complexity of information presented on labels with consumers’ ability to process it in a quick and meaningful manner, and this was particularly important for consumers with lower education and literacy skills. They said there was sufficient evidence from a range of study designs to conclude that providing nutrition information on packages had a positive impact on diet.