"He has been a transformative leader," said Dr. Linda Fried, dean of Columbia University's school of public health. "He has created a model for how to improve a city's health."
Coming into office as a billionaire businessman who made his fortune selling data to Wall Street, Bloomberg was accustomed to using hard, cold research to drive decisions, and it was an approach he used effectively on matters of public health.
Bloomberg pushed to ban smoking in indoor public spaces and prohibit cigarette sales to anyone under 21. He got artificial trans-fat banned from restaurant food — an action that led fast food giants like McDonald's and Dunkin Donuts to change their recipes rather than lose access to the New York market.
He got restaurant chains to start posting calorie counts on their menus, lobbied food processors to add less salt to their products and got city schools to start serving healthier meals. The city distributed millions of free condoms, emblazoned with an "NYC" logo, in an attempt to cut down on teen pregnancy and HIV transmission. One of his pet initiatives essentially created a new public transportation system built around bicycles.
Bloomberg also put new data collection and analytical tools in place to track all the new policies.
Among the results: The adult smoking rate has declined from 21.5 percent in 2002 to 15.5 percent today. Childhood obesity rates inched down among schoolchildren. Life expectancy has increased in the city by three years since Bloomberg took office, compared to 1.8 years in the rest of the country.
"We've shown that local government can take on the biggest public health problems of our time, and win," said the city's health commissioner, Dr. Thomas Farley.
Along the way, he influenced national policy. The Affordable Care Act contained a provision, modeled after the one in New York, that will require chain restaurants nationwide to post calorie counts on their menus. The Food and Drug Administration said last month that it was adopting its own trans-fat ban, and would phase the substance out of the food supply for good.
Bloomberg launched his career as a health policymaker almost immediately on taking office in 2002.
At the time, the municipal cigarette tax was 8 cents a pack. Bloomberg got it increased to $1.50, saying he wanted to make cigarettes so expensive people would be forced to quit. Subsequent increases in the state tax have since raised the per-pack tax to $5.85 within city limits.
Then he went after smoking in public places. New York wasn't the first place to ban smoking in bars and restaurants. California had done it in 1998. But the cultural impact of New York's ban seemed to resonate further.
"The question before us is straightforward," Bloomberg told City Council members at a 2002 hearing. "Does your desire to smoke anywhere at any time trump the right of others to breathe clean air in the workplace?"
As recently as last month, the mayor was still punching away, signing a new law that raised the legal purchase age for cigarettes and set a minimum price of $10.50 per pack. He pushed for, but ultimately abandoned, rules that would have prohibited merchants from even displaying cigarettes for sale. They would have had to hide them in cabinets or under the counter.
Bloomberg's first health commissioner, Dr. Thomas Frieden, who now leads the U.S. Centers for Disease Control and Prevention, said one of the underpinnings of the city's strategy is a belief that many public health agencies are still rooted too deeply in their historic mission of fighting infectious disease, even though chronic lifestyle diseases such as obesity and smoking are the leading causes of preventable death in the U.S. today.
Attacking those illnesses, though, takes willpower to stand up to the natural resistance people have to government telling them how to eat or what to drink.
"I love that he's shoving his idea of good health down my throat," New York University student Brendan Sullivan, 19, said sarcastically last month after the latest smoking law passed.
That disdain for outside considerations may have finally done in a Bloomberg health policy this summer, when a court blocked the administration's attempt to restrict sugary drink sizes at restaurants. The judges, in a strongly worded opinion, said city health officials had exceeded their authority and created restrictions that were arbitrary. Among other things, the portion rules applied only to restaurants, not convenience stores, meaning (much to the dismay of comedians and commentators) it didn't actually apply to 7-Eleven's 30-ounce Big Gulp. That court decision is now on appeal.
And Bloomberg plans to keep the health initiatives going.
One of the world's richest people and most active philanthropists, Bloomberg has already begun pouring his private fortune into public health projects, including a $600 million anti-smoking campaign ongoing in countries including China, India and Russia and a $125 million project aimed at reducing road fatalities in 10 nations.
Bloomberg Philanthropies has an obesity prevention program in Mexico, a reproductive health program in Tanzania and environmental programs aimed at reducing global reliance on polluting coal.
Several of the mayor's top officials are also joining his new consulting organization, called Bloomberg Associates, that will advise other cities around the world on how to implement smart urban policy, including his healthcare initiatives.