By Phillip Matier, Andrew Ross
San Francisco Chronicle

After banning plastic bags from chain grocery stores and bottled water from City Hall, San Francisco Mayor Gavin Newsom has set his sights on soda - working up a plan to charge a new city fee to big retailers of sugar drinks. "The bottom line is that there is a direct nexus between high-fructose corn syrup drinks like colas and Big Gulps and obesity among schoolkids," Newsom said Friday. The idea of taxing soda to combat obesity - which is being touted as the first in the nation - has been roiling around in health circles for some time, including backing from the American Medical Association.