Bread accounts for lower levels of sodium in the British diet than previously claimed by both industry and the Food Standards Agency (FSA), say scientists.

A University of Auckland study found that, apart from table salt, the single largest contributor of daily sodium in the UK was processed meats at 18%, followed by bakery products at 13%. The FSA had been working on the basis that bread accounts for 20% of salt in the UK diet, while the Federation of Bakers (FoB) had put bread’s salt contribution at 15-17%.

FoB director Gordon Polson said he was not surprised by the findings because salt levels were coming down as industry continued to reduce them. "The figure of 20% was not correct... but the Department of Health (DoH) is not in a position to change its view as they haven’t done the urinary analysis and the results won’t be out until 2012," he said.

The last UK urinary sodium survey in 2008 showed a fall in the UK’s average daily salt consumption, from 9.5g to 8.6g. The next study is at least a year away when the government hopes to find it nearer to the 6g a day target.

However, a DoH spokesman said the National Diet and Nutrition Survey report (2008/9) indicated that around 17% of the salt we eat comes from bread. "This [New Zealand] report uses data on food sales and not food consumed hence the difference in our estimates."

The DoH remains tight-lipped about the contents of its Responsibility Deal, due out in March, such as updating salt targets previously set at 1g per 100g for bread and rolls by 2012.