The study, based on polls and interviews with 262 women, says the rules could prove 'positively misleading'. It was commissioned by the Co-op, one of Britain's biggest retailers, which has taken a lead on nutritional labelling and plans to keep its own formula even though this may render it liable to prosecution.
The regulations, part of a 1990 European directive, come into effect before the end of the year. They do not make nutritional labelling compulsory but require a common format where labels are provided. These must show quantities of energy, fat, fibre, sugar and other contents per 100 grams.
But they will make technically illegal the system devised by the Coronary Prevention Group and used by the Co-op, which gives an additional rating - high, medium or low - to the numerical values.
The survey showed that more than half those questioned reached the wrong conclusions about the sugar, fat and calorie content of products using the new labels. With some products, the failure rate was as high as 85 per cent. Consumers also 'don't understand the meaning of sodium - they do not relate it to salt'.
The study concluded that numerical information alone is 'virtually incomprehensible' to the consumer. It suggests devising a 'benchmark' system for the fat content of foods, similar to the units of alcohol introduced by the Health Education Authority.