Put down that can. The sweet soda in front of you may be frosty and cold and just waiting to quench your thirst, but it isn't good for you.

Not just you. Most types of soda aren't good for anyone's health. They're awash in high-fructose corn syrup or other sugary substances that only add calories to your diet. Soda is in the same league as candy bars and frosted donuts--snacks that a growing number of state and local health officials would like to see people consuming less of.

Of course, you may be a lost cause by now. But children can still be cured of sugary addictions--or at least that's what many school districts have decided. Hundreds of them have removed soda from school vending machines. Now, New York City's public health officials are targeting adults, too. They're running ads that depict globs of human fat gushing from a soda bottle. "Are you pouring on the pounds?" asks an ad that appears in the city's subways. It ends with this kicker: "Don't drink yourself fat."

Some jurisdictions are looking at other ways to make soda less enticing. A "fat tax" is one. This is an excise tax that would raise the price of soda and sugar-drenched fruit drinks in the same way that "sin taxes" raise the price of tobacco and alcohol.

In the past 10 years, there has been a 37 percent jump in the number of people in the United States who qualify as being grossly overweight. In the 2009 "F as in Fat" report put out by the Trust for America's Health, 23 states were found to have obesity rates that rose significantly in the course of just one year. High-sugar beverages may not be the primary cause, but they clearly contribute.

Obesity carries substantial public as well as private costs. It is the single greatest factor in diabetes, which helps explain why health care spending for obese people averages nearly $1,000 more per year than for normal-weight people. Most dishearteningly, children are at increasing risk. Childhood obesity tripled between 1980 and 2000. A recent accounting of kids in the Medicaid program found that one in five are too fat.

Anti-obesity crusaders believe that if consumers of high-sugar beverages have to pay more to drink them, they might cut down. After all, raising tobacco taxes lowered smoking rates, especially among young and low-income people. As a result, smoking-related illnesses have dropped over the past generation, reducing the health-cost burden on states. However, William Shughart, an economics professor at the University of Mississippi, isn't sure it will work for soda. He points out that obesity rates in the two states that currently tax soft drinks--Arkansas and West Virginia--are among the nation's highest.

Nonetheless, New York City-style ads, a fat tax or other policy initiatives could make considerable headway against one major cause of the obesity problem. The average American consumes 250 more calories per day now than just two decades ago. While soda isn't responsible for all of those additional calories, its prevalence and popularity inevitably concentrates the public-health mind on all the processed sugar and the calories in that frosty, inviting-looking can of pop.