Chicken McNuggets at a McDonalds fast-food restaurant in Yichang, central China's Hubei province

Chicken McNuggets at a McDonalds fast-food restaurant in Yichang, central China's Hubei province (Str, AFP/Getty Images / April 16, 2012)

NEW YORK (Reuters Health) - Fast food may often be high in salt, but the exact levels seem to vary based on the country you live in, according to a study published Monday.

Looking at fast-food menu information in six countries, researchers found that the same item sometimes had different salt levels in different countries.

In general, certain foods had less salt in the UK than in the U.S. or Canada — like McDonald's chicken nuggets and some chain-restaurant pizzas.

One serving of Chicken McNuggets, for example, came with 1.5 grams of salt (or 600 milligrams of sodium) in the U.S. and 1.7 grams of salt (680 mg of sodium) in Canada. That compared with just 0.6 grams of salt (240 mg of sodium) in the UK.

The chicken nuggets served up in Australia, France and New Zealand had salt levels that fell somewhere in between.

Salt was pervasive regardless of location, however. Overall, fast-food burgers served up an average of 1.3 grams of salt (or 520 grams of sodium) across all countries, with only small national differences.

According to the World Health Organization (WHO), people should get less than 2,000 mg of sodium over a whole day.

It's not clear why salt content in some fast-food items varied by country, said Dr. Norman Campbell of the University of Calgary in Canada, who worked on the study. He and a few of his co-authors are members of the World Action on Salt and Health, which according to its website "works to encourage multi-national food companies to reduce salt in their products and with Governments in different countries highlighting the need for a population wide salt reduction strategy."

One factor in the country differences could be UK government efforts, the researchers write in the Canadian Medical Association Journal. The UK has set voluntary salt-reduction "targets" for the packaged food industry.

The targets do not yet extend to fast food. But some fast-food companies were part of the "roundtable discussion" that helped set the goals, noted Elizabeth Dunford, a researcher at the George Institute for Global Health in Australia who led the study.

The bottom line, the researchers say in their report, is that salt reduction does appear feasible for fast food. The food industry has argued in the past that salt reduction is difficult because it requires new processes and technologies.

And a McDonald's spokesperson pointed out that the study used data from 2010.

"We have already reduced sodium by 10 percent in the majority of our national chicken menu offerings in the U.S. — most recently Chicken McNuggets — a Happy Meal favorite," the spokesperson said. "Sodium reductions will continue across the menu and by 2015, we will reduce sodium an average of 15 percent across our national menu of food choices."


But Campbell said the study is not an attack on the fast-food industry.

Country-to-country variations are seen in packaged food, too. And heavy salt use is not unique to fast food, Campbell noted.

"Yes, salt in fast food is very high," he said. "But if you went to an expensive restaurant, the sodium levels would be very high. If you buy packaged foods, the levels would often be very high."

In the U.S., it's estimated that almost 80 percent of people's sodium intake comes not from their saltshakers, but from the salt that foodmakers add to their products.

Campbell argued that it's up to governments to rein in sodium levels in the food supply.