Are lower socio-eonomic groups making healthier food choices because of front-of-pack labelling? That's a key question the Food Standards Agency hopes that new research it plans to commission will answer.
The study - likely to be limited to examining attitudes towards traffic lights and GDAs, but not other schemes such as Treatwise - will also be designed to assess whether consumers actually use the labelling at all when shopping.
At a meeting in May, details of which have now been made public, representatives of the FSA, retailers, manufacturers and consumer groups agreed the research should "focus on C2s, Ds and Es, but should not ignore other groups".
The study is likely to be funded by the FSA alone, as there is concern the public will not consider the research truly independent if it is funded by industry.
Retailers have pledged to provide data from sales periods pre and post-signposting to assist the study. However, they are reluctant to provide raw sales data, instead offering trend information on a percentage basis. They have also pointed out that confounding factors such as promotions and seasonality will need to be taken into account.
When the FSA opted for traffic lights as its preferred model, it pledged to carry out research into its effectiveness. Since then the grocery industry has been split down the middle, with some retailers and manufacturers opting for GDAs, originally developed by Tesco, and others like Sainsbury's preferring traffic lights. Asda has taken a combined approach.
It is still to be decided who should do the research, how it should be done and when it should start.
Rosemary Hignett, head of the FSA's nutrition division, told the meeting initial results might start to appear within 12 to 18 months of the project starting but that full results could take longer.
Among those present were representatives of Tesco, Sainsbury's, Waitrose, the BRC and FDF.
Research indicates consumers marginally prefer GDAs to traffic lights (The Grocer, 28 October, p7).