(NBC News) - Saying the "deck is stacked" against most people trying to cut down on salt, the Food and Drug Administration asked food companies to cut down how much salt they put in food.

Advocates had hopes the FDA would make lower salt targets mandatory, but the FDA — which recently enraged the sugar industry with tougher labeling requirements — went for a phased-in, voluntary approach instead.

"While a majority of Americans reports watching or trying to reduce added salt in their diets, the deck has been stacked against them," the FDA said in a statement.

"The majority of sodium intake comes from processed and prepared foods, not the salt shaker."

The American Heart Association has been pushing for years to get Americans to eat less salt. Salt raises blood pressure in many (but not all) people, and a third of Americans already have high blood pressure.

The FDA has written draft targets on which the public and industry will be able to comment. They aim to gradually reduce the amount of salt added to processed food.

"The FDA wants to work with food companies and restaurants to gradually adjust sodium levels in food," the agency said, noting that some companies are already starting to do it.

The average American gets about 3,400 milligrams of salt a day. A person with normal blood pressure should only get about 2,300 mg a day and people with high blood pressure should aim for 1,500 mg or less.

"The FDA wants to work with food companies and restaurants to gradually adjust sodium levels in food."

"Americans consume almost 50 percent more sodium than what most experts recommend," the FDA said.

"The science supporting the relationship between sodium reduction and health is clear: When sodium intake increases, blood pressure increases, and high blood pressure is a major risk factor for heart disease and stroke — two leading causes of death in the United States."

The salt industry pushed back hard, saying studies have shown that taking salt too low can be bad for people. Centers for Disease Control and Prevention director Dr. Thomas Frieden and colleagues pushed back against that argument, saying those studies did not clearly show that lowering salt intakes hurts people.

Anyway, they added in a commentary in the New England Journal of Medicine, 90 percent of Americans clearly eat too much salt.

"Nearly half of Americans are already trying to reduce their dietary sodium, and most want low-sodium foods," they wrote."Yet sodium levels are high before food reaches the kitchen or table," they added.

"These voluntary targets can have a significant impact on the nation's health," American Heart Association CEO Nancy Brown said in a statement.

"Lowering sodium levels in the food supply could eliminate about 1.5 million cases of uncontrolled hypertension and save billions of dollars in healthcare costs over the next decade."

The Center for Science in the Public Interest has been suing to try to get the FDA to mandate lower salt levels in food.

"The targets are part of the FDA's response to a lawsuit that CSPI had filed against the FDA last October seeking action on a 2005 petition in which CSPI asked the agency to reduce excess sodium—mostly from salt—in the food supply," the advocacy group said.

"Americans consume almost 50 percent more sodium than what most experts recommend."

"While this is a voluntary approach as opposed to the mandatory approach we asked for and that the Institute of Medicine endorsed, it provides clear goals by which companies can be held accountable. And, it helps level the playing field for those companies that are already trying to use less salt in their food," said CSPI president Michael Jacobson.

That's something the industry has asked for. Food manufacturers have said Americans clearly prefer saltier foods and when one company lowers salt, it often loses sales to another company that keeps salt levels high.

"It's important to note that as restaurants continue to develop lower-sodium items, these efforts are challenged by consumer preference, limited technology, and acceptable lower-sodium options that take into account taste, quality and safety. In addition, availability and feasibility depends on many factors, such as consumer expectations, the type of food, the product's taste profile, and the restaurant's format," the National Restaurant Association said in a statement.

""We are reviewing this draft guidance to assess next steps for our members."

The FDA pointed to studies compiled by the CDC about salt. "In some of these studies, researchers have estimated lowering U.S. sodium intake by about 40 percent over the next decade could save 500,000 lives and nearly $100 billion in healthcare costs," the FDA said.