The UK-based watchdog said yesterday that supermarkets and food manufacturers rejecting FSA guidelines in favour of in-house alternatives are confusing consumers looking to make healthy food choices, as the FSA system has been proven to be the easiest to understand.
A Which? survey found 97 per cent of the 636 consumers asked were able to understand the FSA system, which uses red, amber and green to indicate the levels of sugar, fat and salt in products.
In contrast, Tesco's own labelling policy was understood by just 37 per cent of respondents. Its system relies on showing the Guideline Daily Amounts (GDA) of salt, sugar and fat contained as a daily percentage - requiring prior specific GDA knowledge.
The FSA system also uses GDAs, but interprets what nutrient levels in a product mean against the GDA recommendations allowing consumers to make quick decisions about the products.
"Clearly they [companies not using the FSA system] feel from a marketing perspective the GDA approach shows their products in a better light," said Sue Davies of Which?
"But we are still hoping that food manufacturers and retailers who are not using this will accept the evidence and change their approach.
"Ultimately if they can't come up with a decent system we would be pushing for legislation in this. This is not just based on research but also on EU and FSA guidelines."
FoodandDrinkEurope.com contacted Tesco for a response but at the time of publishing no comment had been received.
The recent FSA labelling recommendations followed months of research involving most large industry stakeholders looking for a consenus on this issue. But many retailers and manufacturers, including Morrison's, Danone and Nestle, have chosen not to adopt the policy.
The BEUC European consumer group is due to meet tomorrow in Brussels to consider the future of Europe-wide food labelling and Which? hopes its latest research will feed the growing debate into whether there needs to be a universal legislative approach to this issue.
"Everybody has a role to play in tackling the growing obesity epidemic in Europe, and proper labelling is part of that," Davies said.