Most of the salt we eat comes not from the shaker in our hands but from the package in our vending machines. Now the Food and Drug Administration is asking food manufacturers to voluntarily cut out more salt from their products before we ever get a chance to snack and unwittingly risk increasing our blood pressure.

Diets high in salt have been linked to high blood pressure. High blood pressure leads to heart disease and stroke. Cutting salt intake by even 400 milligrams each day could prevent 20,000 strokes and 32,000 heart attacks each year, according to the Centers for Disease Control.

Nutritionists put the level of salt most Americans should eat at 2,300 milligrams each day, or the amount contained in a teaspoon of sodium. Older people and those with hypertension should consume less. But most of us are eating about 3,400 milligrams, or 50 percent more than recommended. The CDC says more than 70 percent of our salt intake comes from processed and prepared foods.

The FDA is asking the food industry to voluntarily curb the amount of salt that goes into a range of food from baked goodies to soups. The guidelines would gradually reduce sodium in manufactured and restaurant products. The proposed standards would affect most processed and prepared foods.

Some companies already are cutting back on the salt they put in prepared foods. The CDC says those include Walmart, Unilever, PepsiCo, General Mills, Mars and Nestlé. Darden, which operates restaurants including the Olive Garden, is among those companies.

Consumer health advocates say the FDA move toward voluntary guidelines sets benchmarks so that the public can gauge the sodium content of foods. Advocates point out that the voluntary guidelines stop short of actual regulations to limit salt in processed foods.

They say the voluntary standards proposed by the FDA may help save the lives of thousands of Americans. One in three Americans have high blood pressure, according to the FDA. The number is one in two among African-Americans.