New York City's fight over calorie labeling.

In 2006, New York City's Health Department amended the city Health Code to require the posting of calorie counts by chain restaurants on menus, menu boards, and item tags. This was one element of the city's response to rising obesity rates. Drafting the rule involved many decisions that affected its impact and its legal viability. The restaurant industry argued against the rule and twice sued to prevent its implementation. An initial version of the rule was found to be preempted by federal law, but a revised version was implemented in January 2008. The experience shows that state and local health departments can use their existing authority over restaurants to combat obesity and, indirectly, chronic diseases.