Consumers are rejecting foods with substantially-reduced salt and fat contents, while sudden reformulations have had unacceptable effects on flavour, according to the The British Sandwich Association (BSA).
"Complaints have increased about the blandness of sandwiches and ready meals where salt has been reduced substantially," it said, adding that making changes too quickly would drive consumers towards less healthy choices.
Point-of-sale data showed an 11.7% fall in the value of low fat/low salt sandwich sales over nine months compared with a 15.1% increase in premium products with no reductions, said the BSA.
It cited one unnamed firm's claim of a 275% surge in the number of complaints about poor taste of products since salt content was cut from 3g to 2g ?and said too much credence was being given to lobby groups and not enough to consumer tastes.
The revelation came as Deirdre Hutton, chair of the Food Standards Agency (FSA), urged manufacturers to speed up the rate of change.
BSA director Jim Winship said that the FSA's target to reduce salt to less than an average 2g in sandwiches by 2010 was achievable, but too hard and fast.
Meanwhile Birds Eye, which claims 17% of the frozen foods market, said that when it cut the sodium in its traditional beef stew with dumplings from 0.5g/100g to 0.18g/100g and removed flavourings, sales fell to half of their mid-1990s' levels. "They just didn't like it," said brand director Jerry Wright.
However, its share of the children's food market grew from 30% to 40% in the 18 months since it began cutting the salt, fat and sugar contents and removing artificial colourings, flavourings and preservatives. It had also cut salt in ready meals to less than one-third of guideline daily amounts and to less than one-quarter in meal centres, said Wright, and reduced fat so it contributed less than 11% of energy content.
The FSA's Hutton made her call for fast-track change at a Leatherhead Food International meeting, where chief executive John Bevington echoed manufacturers' concerns over compromising taste for health.
"Healthy cardboard and beneficial pigswill will not survive," he said.