When Mayor Bloomberg sat down to lunch with children during a school visit a few years ago, he was disgusted by the soggy, greasy fries and other junk on their plates.

He pushed for a revamp of school menus and by the start of the next school year, fat-laden meals were being replaced by healthier versions. That same year, 2003, the city began handing out free nicotine patches and Mr. Bloomberg won his crusade to outlaw smoking in bars and restaurants.

Now the city is going after high-calorie foods in bodegas, restaurants, and company cafeterias. Experts say Mr. Bloomberg – a bit of a health nut himself – has targeted unhealthy lifestyles unlike any other administration before him.

“It’s more aggressive than we’ve ever seen in the past,” the dean of Columbia University’s Mailman School of Public Health, Allan Rosenfield, said. “There’s a willingness to take on unpopular but important issues.”

More than 53% of New Yorkers are overweight or obese – lower than the ballooning national 65%, but far too high, according to Mr. Bloomberg and his health commissioner, Dr. Thomas Frieden. Being overweight raises the risk of diabetes, high blood pressure, cancer, and heart disease, which is New York City’s worst killer.