Calories will not be the only health warnings New Yorkers will see at their favorite chain restaurants starting Tuesday.

The city’s sodium warning requirement goes into effect on Dec. 1 at food establishments that are part of chains with 15 or more locations nationwide, according to the Health Department.

Those eateries will need to post icons next to items with 2,300 milligrams or more of sodium — the total recommended daily limit. The rule requires the restaurants to post a warning statement where customers place their orders, and includes combo items, such as an order-by-number meals. 

The statement, which includes a salt shaker icon inside a triangle, explains that items with that icon “have more than the recommended daily limit of sodium and that high sodium intake can increase blood pressure and risk of heart disease and stroke,” the Health Department said.

RELATED: A high-sodium diet could be hurting more than your heart

The measure, which was passed unanimously in September by the city’s Board of Health, makes New York the first city in the country to require chain restaurants to post warning labels next to menu items that contain high levels of sodium. 

The average New York City adult consumes almost 40 percent more sodium than the recommended limit per day, according to the Health Department.

"The vast majority of adults in New York City consume more sodium than recommended, and too few understand the link between high sodium intake and hypertension, heart disease, and stroke," said the city’s health commissioner, Dr. Mary Bassett in a statement. "These warnings are needed in restaurants because the majority of sodium in our diet is not coming from what we decide to add with the salt shaker at the table, it's already in the food when we buy it. These icons will help New Yorkers make more informed choices when dining out."

Chains that fall under the new sodium requirements have 90 days to comply with the new rule before they face a possible fine. 

Before the rule even goes into effect, the National Restaurant Association is planning a lawsuit against the Health Department, Politico New York reported.

“While the Board of Health thinks they are targeting corporate chains, in reality they are dealing yet another blow to many of New York’s small businesses that have been working and continue to work hard to provide nutritional access to their customers," Christin Fernandez, spokesperson for the National Restaurant Association said in a statement to Politico. "That is why we are taking legal action against this latest assault which goes too far, too fast for New York’s restaurant community."