The Food and Drug Administration is trying to crack down on your salt intake.

The agency announced guidelines on Wednesday for food companies and restaurants to reduce sodium in the foods they make by about 12 percent over the next 2½ years.

The guidelines are voluntary, but experts say they signal a new willingness on the part of the FDA to crack down on food manufacturers. Just weeks ago the agency issued new guidance about heavy-metal limits in baby foods. Health advocates said this week’s salt announcement is more significant than even the agency’s trans fat ban in 2015, because it involves an ingredient contained in nearly every food that is made, and as sodium has long been criticized as a key culprit in the obesity epidemic ravaging the nation.

Health advocates are pushing the FDA to strengthen these voluntary goals and make them mandatory, and to go even further by requiring new warning labels that would flag excessive sodium in processed food.

Table salt’s scientific name is sodium chloride, too much of which can raise blood pressure, which is a major risk factor for heart disease and stroke. More than 4 in 10 American adults have high blood pressure, and the numbers are even higher across minority populations.

About 70 percent of the sodium people eat comes from packaged, processed and restaurant foods, according to the FDA; not from the salt shaker on the kitchen counter. This makes it really hard for people to know how much sodium they are consuming.

The federal government has tried to limit consumers’ salt intake by providing stricter dietary guidelines that recommend just a teaspoon a day per person, or about 2,300 milligrams. But people either don’t pay attention or can’t easily determine the salt content in the foods they eat. Many Americans consume twice that. It’s easy to do. A single Quiznos classic Italian sub has 3,760 mg of sodium. Pizza Hut’s nine-inch personal “PANormous” meat lovers pizza contains 3,670 mg.

The FDA has taken aim at hundreds of categories of processed, packaged and prepared foods, with the goal of reducing Americans’ salt consumption to about 3,000 milligrams, still way higher than organizations like the American Heart Association recommend.

“The human and economic costs of diet-related diseases are staggering,” Health and Human Services Secretary Xavier Becerra said in a statement. “Hundreds of thousands of Americans die each year from chronic disease related to poor nutrition, and by some estimates, the total economic costs range upward to $1 trillion per year.”

The FDA’s decision will reduce sodium across the board, according to Donald Lloyd-Jones, chair of the department of preventive medicine at Northwestern University and president of the American Heart Association, “leveling the playing field” so that people’s taste buds will adapt and, over time, not crave as much saltiness.

“The only way to make a meaningful reduction is by changing the food supply,” Lloyd-Jones said. “This isn’t about asking people to make individual choices.”

The guidance, which finalizes 2016 draft guidance, acknowledges that many Americans consume much more sodium than recommended, including nearly all school-age children.

During the Trump administration, Agriculture Secretary Sonny Perdue weakened school nutrition standards for sodium, fat and fiber, all of which had been tightened during the Obama administration. Perdue cited food waste and nonparticipation as key rationales for the shift. And since the pandemic, the federal government has relaxed school nutrition standards in an effort to accommodate supply chain problems that have left school nutrition administrators scrambling.

The Healthy, Hunger-Free Kids Act of 2010 required school nutrition to be improved in three stages, said Peter Lurie, president of the nonprofit Center for Science in the Public Interest. The Trump administration limited the scope of the second stage and took the third stage off the table entirely, he said, so the FDA still has to set new deadlines for reinstating these stricter sodium, unhealthy fat and higher fiber guidelines for school food.

For food manufacturing companies and restaurant chains, the new guidelines will entail recipe reformulations and, in some cases, new product labeling, all of which can be expensive.

The Grocery Manufacturers Association, the trade association that represented some of the biggest food brands, was involved in pushing back against stricter FDA sodium limits. The GMA became the Consumer Brands Association at the beginning of 2020, and since then the organization has not actively engaged on this issue. The CBA had no statement about what this week’s FDA announcement would mean for manufacturers.

The National Restaurant Association provided feedback while the FDA was writing this guidance, said Laura Abshire, the group’s director of food and sustainability policy.

“While we look forward to reviewing the final guidance and are hopeful it incorporates our suggestions, the restaurant industry continues to provide options to address customers’ desires and health needs,” Abshire said.

Lurie said the problem with much of the existing literature about the ills of too much sodium can be reduced to a simple syllogism: If you curb your sodium intake (A), your blood pressure will go down (B). People with high blood pressure (B) are prone to cardiovascular disease (C). So, A is connected to B, B is connected to C, but is A connected to C? The science has been unclear on this, leading many people to conclude that salt is not that bad.

He said a significant new study published in September in the New England Journal of Medicine makes it clear: A connects to C; if you lower your sodium chloride intake, you lower your risk for cardiovascular disease.

Perhaps this new study will cut through the conflicting noise about salt intake, Lurie said, but because Americans’ home salt shakers are responsible for such a tiny fraction of the salt we eat, he said this new guidance calling for changes in food manufacturing is a legitimate moment “for the strong hand of government.”