As obesity rates continue to rise in North America, a U.S. health advocacy group is urging major fast-food outlets to prominently display calorie information on menu labels.

"Without nutrition information it's difficult to compare options and to make informed choices," Margo Wootan, director of Nutrition Policy at the U.S. Center for Science in the Public Interest, told reporters on Monday. "How can a person exercise personal responsibility without information?"

Wootan said there are numerous studies that link eating out with higher caloric intakes and with an increase in rates of obesity. Her group is pushing legislators across the U.S. to implement menu labelling as a low-cost way to help people watch their weight.

The press conference comes as New York City municipal officials prepare to debate changing a new rule that requires major fast-food chains to prominently post calorie information on menus or menu boards.

Attempts to impose menu-label rules in at least 12 states, including New York, have failed, reports The New York Times. Similar initiatives are pending in at least nine other states.

New York City became the first municipality to circumvent state and city lawmakers by getting the Board of Health to mandate that the labels be used.

On Wednesday, the chairman of the city council's Health Committee is expected to put forth legislation that would require nutritional and calorie information to be made available in pamphlet form or on a poster or kiosk -- instead of on menus.

Wootan rejected the idea, telling the Times that it "goes against what the public wants."

She said that if anything, city council should "improve upon what the regulation has already done."

But restaurant industry representatives say the regulations unfairly target fast-food chains, which only make up about 10 per cent of New York City's restaurants. They also say such initiatives are too difficult to implement.

"After all, Starbucks has 84,000 different drink offerings, and Taco Bell has around 25 different kinds of burrito," Richard Lipsky, a lobbyist for the National Restaurant Association, told the Times.