BOSTON MAYOR Menino belted a refreshing blow against obesity this week, issuing an executive order to end sales of sugary drinks on city-owned property and at city-run events. Barbara Ferrer, Boston’s public health director, said in an interview, “We’re not banning people buying them at supermarkets or at the corner store. What we are doing is sending the message that you don’t have to sell soda everywhere. We’ve decided to model what a healthy community would look like. We can’t match the $3 billion marketing campaign for soda. But what we can do is create environments where people realize they don’t have to have it all the time.’’

The move keeps Boston in the vanguard of cities like San Francisco, New York, and Los Angeles, which have enacted a variety of municipal limitations and labeling campaigns on sugared beverages and fatty fast food. Even though Massachusetts is overall one of the leanest states in the nation, nearly a third of African-Americans and Latinos in Boston are obese. Obesity raises the risk for heart disease, diabetes, and cancer, costing the nation an estimated $147 billion a year.

“I’m respectful of people who say this is a nanny state,’’ Ferrer said. “We’re not against a soda at a birthday party, but the medical costs of consuming it every day and other costs to government are so staggering that we’re compelled to do something. The irony here is that some people may say, ‘Hey, you’re limiting my options.’ But the reality is that all along we’ve been limiting healthy options.’’

The case for treating soda more like a toxin than a treat gets stronger with every study. A University of California study last year said that "all lines of evidence" indicate that sweetened beverages have contributed to the obesity epidemic, likely accounting for at least 20 percent of American weight gain between 1977 and 2001. Evidence cited by the authors also indicate that soft drinks now contribute more calories to the diet than any other single type of food.

The public health commission says the order would affect about 100 vending machines, along with concession stands at City Hall, fire and police stations, youth and family centers, and other municipal buildings. Sweetened soda, tea, and sports energy drinks will be phased out. They can be replaced with products such as 100 percent juices, lowfat milk, and bottled water. Coming after the banning of soda sales in schools in 2004, the city is sending an important signal that it cannot lecture youths to stop drinking sodas if it is selling them to city workers.

It is also important in terms of momentum, as there are early indications such policies are helping. Harvard School of Public Health researchers found an 18 percent drop in soda consumption by students two years after the 2004 ban. Similarly, the University of Nebraska published a regional study last fall that found that schools that ban junk food are likely to have 18 percent fewer overweight and obese students than schools that do not ban junk.

Coffee shop vendors at city agencies told the Globe they were concerned that banning soda would mean a drop in revenue. One said that not having soda available would be “bad for morale.’’ There indeed may be an initial drop, but the city says revenues from beverage and snack machines in schools are back up to 85 percent of their original levels, after falling to 60 percent.

Besides, the morale of someone who cannot score a Coke pales in comparison to the mortal threat of obesity and diabetes. Ferrer said an employee at City Hall was at first skeptical about Menino’s new ban, until her own daughter, a Boston Public Schools student, came home one day and said, “I’m not drinking soda anymore.’’ Ferrer said, “When daughters are bringing home the message to the mother that soda is bad for you, there’s hope.’’

Derrick Z. Jackson can be reached at jackson@globe.com.

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