The city's Health Department announced on Monday that it is coordinating a nationwide effort to reduce salt in restaurant and packaged foods by 25 percent over five years.

The National Salt Reduction Initiative, a coalition of cities and health organizations, hopes the food industry will back its campaign to combat high blood pressure, heart attacks and strokes by voluntarily reducing the sodium in the U.S. food supply.

The announcement met with mixed reaction. Many food makers have already begun to cut salt content and said the reduction targets were reasonable, but some critics called it another attempt to regulate what should be a free choice.

Bloomberg, who has just begun his third term as mayor, has crusaded for healthy living. Apart from the smoking and trans fat bans, the city required chain restaurants to post calorie counts of their menu items and started ad advertising campaign against sugary drinks.

Companies are aware of the push to reduce salt and the New York initiative represents a challenge, said Tom Forte, an analyst at Telsey Advisory Group, an equity research firm.

The restaurant industry will change its offerings if demand is there, but there is not a lot of proof previous measures in New York caused any major shifts in consumer behavior, Forte said.

The effort targets restaurants and packaged food because only 11 percent of the sodium in Americans' diets comes from their saltshakers. Nearly 80 percent is added to foods before they are sold, the Health Department said.

High blood pressure, heart attacks and stroke kill 23,000 New Yorkers and 800,000 Americans per year, costing untold billions in healthcare expenses, the Health Department said. Salt intake has been increasing steadily since the 1970s, with Americans consuming about twice the recommended limit of salt each day.

Consumers can always add salt to food, but they can't take it out, said New York City Health Commissioner Thomas Farley.

But J. Justin Wilson of the Center for Consumer Freedom, an industry-funded group that lobbies against restrictions on smoking, alcohol and the restaurant and food industries, called the initiative paternalistic and warned that if the City doesn't get its way, it may try to make the proposals obligatory.

First it was trans fats, then it was mandatory labeling. The City's Board of Health knows best.

Food manufacturers said the proposals are reasonable and have been a part of their strategy for some time.

Kraft Foods is supportive of the overall goal of New York City's sodium reduction initiative, said Susan Davidson of Kraft Foods Inc.

The New York City Health Department's Dr. Sonia Angell said the sodium cuts are not about banning any single product but making sure the mix of high and low sodium products is balanced so that it packs a lower wallop of sodium for all of us.

(Reporting by Basil Katz; editing by Daniel Trotta and Anthony Boadle)