When applied to ready meals and sandwiches, front-of-pack traffic-light labelling did not change the purchasing habits of consumers over a four week period, according to results published in the current issue of Health Promotion International.
“This short-term study based on a small number of ready meals and sandwiches found that the introduction of a system of four traffic-light labels had no discernable effect on the relative healthiness of consumer purchases,” wrote the researchers, led by Gary Sacks from the University of Oxford’s School of Exercise and Nutrition Sciences.
“Further research on the influence of nutrition signposting will be needed before this labelling format can be considered a promising public health intervention,” they added.
Nutrition labelling is a hot topic since a new regulation that would make one standardised system mandatory across the EU is currently being debated. At present many different schemes are used in the EU, and indeed within individual member states, which some fear could confuse consumers.
Traffic light labelling, which uses red, amber and green to indicate whether or not foods are high in the same nutrients, has been finding favour in many countries, with a recent survey in Ireland showing that 39 per cent of respondents saying they preferred the traffic light labelling scheme.
Despite the results of the small Oxford study indicating the system is ineffective in changing purchasing habits, a recent survey in the UK found that British consumers like traffic-light labelling. Indeed, the UK’s Food Standards Agency has been encouraging use of traffic light colours on foods that have high, medium, and low levels of certain nutrients.
Sacks and his co-workers studied the percentage changes in purchasing of six forms of ready meals and 12 sandwich varieties for four weeks before and after traffic-light labels were introduced onto the products.
Results showed that for ready meals, sales actually increased slightly, by about 2.5 per cent, in the four weeks that followed traffic-light labelling. On the other hand, sandwich sales did not change.
“Critically, there was no association between changes in product sales and the healthiness of the products,” wrote the researchers.
The UK’s FSA were contacted for comment, but were not available prior to publication.
Insufficient data? Traffic lights work!
Commenting on the study’s findings, a spokesperson for the FSA told FoodNavigator: “This study relates to information supplied by one supermarket, shortly after they started applying traffic lights to a limited number of products and does not provide sufficient data to conclude whether or not traffic light labelling helps people to make healthy choices. Comprehensive sales data would be required from all supermarkets tracked over time before any assessment could be made of how it influences purchasing choices.
“However, we know that manufacturers are reformulating their products using the traffic light criteria to help produce healthier products, and that a wider range of healthier products has become available over the three years since the traffic light approach was introduced. In some cases, people are making a deliberate decision to choose the healthier options and in other cases they are buying the same products which, due to reformulation, are inherently healthier than before the approach was introduced.
“The independent evaluation commissioned by the Agency, remains the most robust study on consumer use and comprehension of front of pack labelling to date. This research looked in detail at how people actually use front of pack labels when shopping, and at home and found that the information given on the label was one of many factors which influenced consumers' purchasing decisions. The study found that traffic light colours increased consumers’ ability to make healthier choices, and helped people to make quick decisions while shopping,” said the spokesperson.
Source: Health Promotion International
December 2009, Volume 24, Pages 344-352
“Impact of front-of-pack ‘traffic-light’ nutrition labelling on consumer food purchases in the UK”
Authors: G. Sacks, M. Rayner, B. Swinburn