Why the label on your turkey is gobbledegook

Consumers are confused by nutritional labels on turkeys, an Evening Standard investigation has found.

Some labels overestimate the fat content drastically - one Sainsbury's bird tested claimed to have 5.4 grams of fat per 100g, but our tests found just one.

Others underestimate salt and fat by up to half, and there were widespread discrepancies on all the information.

Legally, supermarkets do not have to provide any information, and many of the organic turkeys in our test came without labels.

According to the Food Standards Agency, labels are only required if nutritional claims about the product, such as it being low in fat, are made.

Supermarkets were today forced to admit much of the information on labels is wrong.

"The label on the frozen turkeys represent the nutritional values of a typical bird, and are only intended to be a guide," said a Tesco spokeswoman.

Harrods claimed that as it only sold organic free-range birds, it had "no plans" to add any nutritional information or add labels.

One of the country's biggest turkey producers, Bernard Matthews, also said the nutritional information was only a guide.

"Every bird is different, and fat in particular changes a lot depending on the bird's diet and lifestyle, so the labelling is designed to give consumers a guide to the nutritional information-and I think that explains why your testing has come up with different results to what is on the label," explained Jeremy Hall, Bernard Matthew's technical director.

However, he admitted the current system needed overhauling.

"By the spring we will have improved our labels, and include information like what type of fat is in there. It's something we think we need to do to make sure consumers have enough information."

Experts today said they were surprised by the results and have called for an investigation.

Nutritionist Mary Stuart said: "This is simply unethical. People need to believe what they read on the labels. One would have hoped the companies would have been honest."

She believes the results could seriously dent consumer acceptance of food labelling.

"To ensure you have a good diet obviously we advise people to look at these labels, and I think the majority of people still don't read labels enough. This certainly isn't going to help."

The Food Standards Agency today pledged to investigate the results, and the Evening Standard has passed on the full results. A spokesman said: "If it was found a company was making incorrect nutritional claims, then under the Food Safety Act they could be prosecuted by local authorities.

"However, there are several different ways of carrying out these tests and it may be that manufacturers are using different methods. But we will certainly investigate the situation."

Nutritionist Natalie Savona said the test results could help people consider organic and traceable foods more.

"You only really need to worry about the label with processed food. If you're buying organic then generally you know it's not going to have any added extras. But this confusion is a shame as turkey is a really good source of protein and a very healthy food in general."