Bread and cereal manufacturers have reduced the salt content of their products but levels still remain high, according to the latest research.

The salt content of many bread and breakfast cereals sold in Australian supermarket has been reduced, but still remains high, a study suggests.

Researchers from the University of Sydney's George Institute for Global Health have conducted the first evaluation of the Food and Health Dialogue, the
Government's flagship programme to get manufacturers to make their food healthier.

Overall, they found salt levels in bread and cereals have fallen over the past four years.

But salt content still remains relatively high due to the "soft" targets agreed between industry and government, they said.

Bread is the main source of salt for most Australians, and the overall proportion of breads that met the target - 400 milligrams per 100 grams - rose from 42 per cent to 67 per cent.

The Dialogue was set up in 2009, with food manufacturers agreeing to cut sodium levels in bread, cereals and processed meats by the end of 2013.

Study leader Professor Bruce Neal said a number of bakers have made significant progress towards meeting the agreed targets.

"Coles and Woolworths, for example, got all their breads down to the target," he said.

"Goodman Fielder isn't quite there yet but it made really significant improvements." Average salt levels in cereals fell from 316mg to 237mg per 100g of product.

"Kellogg's have made significant improvements but there are still some pretty salty products out there because this was a soft target," said Prof Neal.

"The breakfast cereal industry was pretty clever about what it agreed to, and government should have taken a firmer stand.

"But it's certainly progress." The proportion of processed meats meeting the target rose from 28 per cent to 47 per cent but many products still remain very salty, he said.

Salt causes high blood pressure, one of the most important risk factors of heart disease - the leading cause of death in Australia.

More than 46,500 people died of heart disease in 2011.

The average adult salt intake in Australia is estimated to be 9g salt per day.

The recommended upper limit is 6g of salt a day and the suggested dietary target is 4g a day.

Copyright AAP 2014