MONDAY, April 16, 2012 (Health.com) — It’s no secret that fast-food fare like burgers, french fries, and fried chicken tends to be high in sodium. According to a new study, however, American fast-food customers may be getting a larger dose of sodium than their counterparts in other countries—even if they order the exact same items off the menu.
In the study, published this week in the Canadian Medical Association Journal, researchers analyzed the posted nutritional information for more than 2,000 items sold in multiple countries by the world’s six largest fast-food chains: Burger King, Domino’s Pizza, KFC, McDonald’s, Pizza Hut, and Subway.
Overall, the researchers found, fast food tended to be saltier in the United States than in the other countries included in the study: Australia, Canada, France, New Zealand, and the U.K. What’s more, the sodium content of the same menu items at the same chains varied by country, sometimes widely.
For most menu items, the sodium content differed by no more than 20% to 30% from country to country. Burger King’s Double Whopper, which contained an average of 1,050 milligrams of sodium, varied by 240 milligrams at the most, for instance.
But in some cases the difference was dramatic. The Chicken McNuggets sold in the United States contained 2.5 times more sodium than the McNuggets sold in the U.K. Likewise, the sodium content of a Subway club sandwich was more than twice as high in the United States as it was in France.
It’s not clear from the study what accounts for these variations. Several factors could make it difficult for restaurant chains to reduce or standardize their sodium use across countries, says Joy Dubost, Ph.D., director of nutrition for the National Restaurant Association, a trade organization that represents all of the chains covered in the study.
“There are challenges not identified by this study,” Dubost said in a statement, “including availability of acceptable reduced-sodium items in the supply chain, consumer variability in taste preference across the U.S. and among the various countries, regulatory constraints, as well as availability of new and existing alternatives to sodium.”
Local suppliers and regulations are probably more influential than local tastes, says Norm Campbell, M.D., one of the study authors and a blood-pressure specialist at the University of Calgary, in Alberta.
If restaurants were largely responding to consumer demand for saltier items, Campbell says, one would expect to see a close relationship between the sodium content of fast food and a country’s per capita sodium intake (a rough index of a culture’s taste for salt). “We did not see that,” he says.
Although they can’t pinpoint the reasons for the sodium disparities, Campbell and his colleagues say the study findings show that limitations in food-processing technology are not a barrier to providing lower-sodium products, as the food industry has claimed.
“We found multiple examples of low-salt choices, and for the same product across different countries there’s variation in the amount of salt that’s added,” Campbell says. “From that perspective, it would appear that it’s not very challenging to lower the amount of salt in food products.”
Next page: U.K. sodium-reductions efforts are working