Dr. Stephen Havas, a research professor of preventive medicine at Northwestern University Feinberg School of Medicine in Chicago, and the Center for Science in the Public Interest in Washington assessed the sodium content in selected processed foods and in fast-food restaurants in 2005, 2008 and 2011.
The study, published in the Journal of the American Medical Association, found from 2005-11, the sodium content in 402 processed foods declined by approximately 3.5 percent, while the sodium content in 78 fast-food restaurant products increased by 2.6 percent. Although some products showed decreases of at least 30 percent, a greater number of products showed increases of at least 30 percent, the study said.
"The voluntary approach has failed," Havas said in a statement. "The study demonstrated the food industry has been dragging its feet and making very few changes. This issue will not go away unless the government steps in to protect the public. The amount of sodium in our food supply needs to be regulated."
A typical American consumes an average of almost 2 teaspoons a day of salt, vastly higher than the recommended amount of three-fifths of a teaspoon or no more than 1,500 milligrams. About 80 percent of daily sodium consumption comes from eating processed or restaurant foods -- very little comes from salt we add to food, Havas said.
"The only way for most people to meet the current sodium recommendation is to cook from scratch and not use salt," Havas said in a statement. "But that's not realistic for most people."