Green light for colour-coded labels: Study

By David Burrows

- Last updated on GMT

'[colour-coded] increased sensitivity to health and decreased weight on taste' ©iStock/GoldStock
'[colour-coded] increased sensitivity to health and decreased weight on taste' ©iStock/GoldStock

Related tags Nutrition European union

Traffic light nutrition labels can sway consumer decisions towards healthier options, according to scientists in Germany and the US.

Researchers at the University of Bonn and the Ohio State University found that colour-coded labels “significantly increased”​ healthy choices by increasing the so-called ‘drift rate’ towards healthier products. The effects are strongest when a number of nutrients are displayed rather than, say, sugar alone.

“Salient labels [in this case colour-coded ones] increased the sensitivity to health and decreased the weight on taste, indicating that the integration of health and taste attributes during the choice process is sensitive to how information is displayed,”​ they concluded.

These labels therefore “proved to be more effective in altering the valuation process healthier, goal-directed decisions”.

The findings come at a time when the use of colour-coded labels is under scrutiny. Last month, a group of MEPs renewed calls for the European Commission to assess the UK’s traffic light labelling scheme. Meanwhile, the UK Prime Minister recently hinted at changes to the country’s labelling rules following Brexit.

France has also just launched a massive trial​ to test four different labelling approaches, including colour-coded options.

Tasty v healthy

In the new study, published in the journal Judgment and Decision Making,​ 44 adults were first asked to what extent they like 100 different foods. Half of these products, including chips, chocolate bars and cookies, were less healthy. The other half were more desirable for health reasons, for example rice waffles, crispbread and natural yoghurt.

They were then asked to choose from two products, one healthy and one less so, using a mixture of information-based labels (grams and percentages, for instance) and colour-coded ones. For the traffic lights, red symbolised a high proportion of fats, sugar or salt, whilst green represented a low proportion. Yellow was somewhere in between.

When grams and percentages were used, people were “above all guided by their taste”,​ noted Laura Enax from the Centre for Economics and Neuroscience (CENs) at the University of Bonn. But when the information was combined with the traffic light colours, the “health aspects of the product played a greater role”​.

On average, it was “several percentage points more likely”​ that healthier foods were chosen when the traffic light colours came into play than when pure figures were shown on the food packaging, she said. “The traffic light colours seem to have a much more favourable effect here than pure percentages and grams,”​ added co-author Professor Bernd Weber from CENs.

In two additional experiments, the researchers offered simplified nutrition information based on sugar alone. The effects were “much smaller”​ compared with the full nutrient traffic light, Enax said.

MEPs see red

Some EU countries have questioned whether traffic light labels actually protect consumers’ health.

Last month, around 100 MEPs backed Italy’s claim that the UK scheme – a voluntary approach using nutritional information and colour coding – violates Article 35 of Regulation 1169/2011​ on the provision of food information to consumers. They called on the European Commission to launch a full investigation into the commercial impact of the labels, which they claimed had hit sales of certain products.

Legal experts told FoodNavigator that the challenge is “difficult to understand”​ in light of planned changes to European laws later this year. The UK’s Department of Health has also said there is “no credible evidence​that the front-of-pack scheme acts as a barrier to trade.

The UK is keen to revisit food labelling laws once it is freed from the EU’s regulatory system. The Childhood Obesity Plan, published in August, stated that Brexit will offer “greater flexibility”​ in relation to food labelling.

The Prime Minister Theresa May told last weekend’s Conservative Party conference that leaving the EU “means we are going, once more, to have the freedom to make our own decisions on a whole host of different matters, from how we label our food to the way in which we choose to control immigration”.

Source: Judgment and Decision Making

Published at:

Salient nutrition labels increase the integration of health attributes in food decision-making”

Authors: Laura Enax, Ian Krajbich, Bernd Weber

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