NEW YORK, NY January 22, 2008 —Burger King's Triple Whopper Hamburger contains 1,230 calories...and starting March 31st, the city wants you to see that number posted on the fast food chain's menu board.

REPORTER: The Board of Health unanimously approved a revision to its calorie statement rule. Health Department nutrition specialist Dr. Lynn Silver says it will help fight fat.

SILVER: Calorie information will provide one very useful tool to consumers to help make healthier decisions when they eat out and encourage restaurants to improve their menu offerings. It alone won't help the obesity epidemic, but it can help.

REPORTER: But restaurants say the new rule is overzealous, and overreaching. The New York State Restaurant Association says it plans to launch another legal challenge.