The regulation, which takes effect March 31, was altered slightly after a judge rejected the city's first attempt last year.
The new regulation applies to any chain that operates at least 15 separate outlets, including those that do not currently provide any information on calories. Major fast food chains make up about 10 percent of the city's restaurants.
Several chains, such as McDonald's and Burger King, have the information available but do not list it on their menu boards.
"It's going to get a lot easier to make informed choices at New York City's chain restaurants this spring," said Margo Wootan, nutrition policy director for the Centre for Science in the Public Interest. "We expect that many more cities, counties and states will require menu labelling once they see how easy it is for these chains to list calories on menus."
But J. Justin Wilson, senior research analyst at the Centre for Consumer Freedom, called the new law an example of "nanny-state public health policies."
"It doesn't take a Ph.D. in nutrition, let alone a high school diploma, to tell the difference between a 12-piece bucket of chicken and a salad," he said.
The regulation affects fast-food chains because their standardised menus make it feasible to determine calorie counts.
The restaurants will be required to display calorie counts "in close proximity" to items on their menus or menu boards in letters and numbers at least as big as the name of the item or the price.
Health Commissioner Dr Thomas Frieden said the law would strike a blow against obesity by helping consumers make informed choices.
"Today in New York City, two-thirds of adults are overweight or obese, and half of children are overweight or obese," he said. "It's a serious epidemic." - (Karen Matthews/Sapa/AP)
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