Sales of products labelled with their glycaemic index (GI) may not grow as quickly as expected due to the high cost and length of time needed to assess them, according to a leading pizza maker.
Becky Jones, development manager at Greencore Pizza, said that the cost of GI labelling, hailed as the next big diet craze, was proving a barrier.
"It's difficult and very expensive to determine the GI index of food. From a manufacturing point of view that will limit how we embrace it," said Jones. "We're sitting back a little bit and just waiting to see what develops."
Finding a food's GI index can take up to three months because it involves using volunteer consumers. One product test can cost £1,900, according to Reading Scientific Services.
Last September Tesco, which intends to have 1,000 products GI labelled by the end of this year, sent 250 for testing, but has labelled only around 10 so far. It declined to say whether suppliers would have to foot the bill for GI testing in future.
Mary Young, marketing manager at food company Retail Brands said that consumers were not ready for GI labelling.
"There's a huge amount still to be done," she said. "It doesn't matter what claims we make with regards to how many grammes of carbohydrates; it means nothing. Consumers in the UK are just getting to grips with calories. I think as an industry we've raced ahead and I don't think we have actually taken on board that consumers are way, way behind."
Erik Millstone, the director of science and technology policy studies at the University of Sussex, who is leading a 30-month European Commission-funded project looking at how companies can tackle obesity, agreed.
"One of the things that it is quite clear is that there are high levels of support from a wide range of stakeholders right across the European Union for improvements in food labelling," said Millstone. "But I'm sorry to say there is little or no enthusiasm for GI."