THE mandatory nutrition information that appears on all processed foods in Australia is often inaccurate and misleading, according to the first analysis of how well the claims reflect packet contents.

Even allowing for a 20 per cent margin of error on the specified amount, as many as 84 per cent of labels incorrectly stated the quantity of at least one component, the survey of 70 packaged products conducted for the NSW Food Authority found.

In one brand of chips, scientists found the amount of trans fat - which has been implicated in the development of heart disease - was 13 times higher than claimed on the label. (Trans fat results when hydrogen is added to vegetable oil to make shortening or margarine. The process extends the shelf life of fatty products such as biscuits and snack foods.)