POPULAR brands of prepared meals have been increasing the salt content of their products, despite the introduction of voluntary industry sodium targets aimed at curbing people's intake.
The Australian Division of World Action on Salt and Health said that by last year, producers of such meals should have met an interim target of 280 milligrams of salt per 100 grams, with the hope of revising and reducing that target once it was met.
But Coles meals had increased the average sodium content by 13 per cent in the four years to 2011, with its chilled products containing 310 milligrams of sodium per 100 grams. SunRice meals contained an average of 297 milligrams of sodium per 100 grams. Although McCain significantly cut the salt in its products, it still had one of the highest average levels of sodium of all the major brands, 310 milligrams per 100 grams.
The study was published in the latest Asia Pacific Journal of Clinical Nutrition and its lead author, Anthea Christoforou, said it was disappointing voluntary efforts by the food industry to meet AWASH targets had failed.
''From 2011, the salt content in an average ready meal represented 37 per cent of the daily recommended upper intake of salt, which is six grams per day, and 54 per cent of the lower recommended intake of four grams,'' Ms Christoforou said.
The study examined prepared meals from the freezer, fridge and the shelf, including lasagne, stir-fry, pasta, salads, soups and pies bought from Coles, Woolworths and three smaller independent retailers.
Ms Christoforou said the federal government's Food and Health Dialogue should set sodium targets specific to prepared meals, as it has already for other food categories.
A Heart Foundation dietician, Barbara Eden, said the meals needed to contain less than 300 milligrams of salt per 100 grams to get the foundation's tick.
''People are still consuming too much sodium, which increases blood pressure and, therefore, the risk of cardiovascular disease,'' she said.
''It is a major concern because a lot of salt is hidden and nutrition labels are difficult to understand.''
A Coles spokesman said many of its higher sodium products were from ''specific cuisine styles such as Indian and Thai''.
''[These] often have a higher sodium content due to the use of authentic ingredients,'' he said.