The move comes ahead of a new regulation that would require restaurant chains and vending machines to post calorie information as early as next year, although the timetable and specifics for complying with that requirement are still being worked out.
"They're seeing the writing on the wall and want to say that it's corporate responsibility," said Mike Jacobson, executive director of the Center for Science in the Public Interest, which advocates for food safety and nutrition.
The U.S. Food and Drug Administration has proposed a less-stringent amendment that would allow vending operators to post the information on a poster on the side of the machine, Jacobson said. But he said the industry's announcement Monday shows posting calories right on machines is perfectly feasible.
"This would be an important step forward," he said. "Currently, people don't think about calories when they go up to a vending machine. Having the calories right on the button will help them make choices."
The American Beverage Association, which represents Coca-Cola Co., PepsiCo, and Dr Pepper Snapple Group, said the calorie counts will be on the buttons of the machines, which will also feature small decals reminding the thirsty that they can choose a low-calorie drink.
The vending machines will launch in Chicago and San Antonio municipal buildings in 2013 before appearing nationally.
Without providing specifics, the American Beverage Association said the machines will also increase the availability of lower-calorie and zero-calorie drinks.
"We have market research that says consumers really like this -- they like choice, they like the ability to make choices," said Susan Neely, president of the American Beverage Association.
But she said the group has not done any research on whether providing such information impacts the choices people actually end up making. Notably, the ABA has aggressively fought New York City's ban on the sale of large sugary drinks, as well as measures in other municipalities that would tax sodas.
A mock-up of the new machine provided by Coca-Cola showed 20-ounce bottles of its flagship drink and Sprite inside vending machines, with labels on the glass stating "240 calories."
The move also comes as the soda industry has come under increasing fire for fueling rising obesity rates. Last month, New York City approved a first-in-the-nation plan to prohibit the sale of sugary drinks over 16 ounces in the city's restaurants, movie theaters and stadiums. The beverage industry aggressively fought the measure, saying it takes away customer choice.
This November, voters in Richmond, Calif., will decide whether to approve a penny-per-ounce tax on sugary drinks.
Soft drink makers are also dealing with shifting consumer habits. Soda consumption per person has been declining in the U.S. since 1998, according to the Beverage Digest. The decline is partly the result of the growing number of drink options, such as flavored waters, bottled teas, and sports drinks.
As a result, Coke, Pepsi and Dr Pepper are focusing on developing more diet drinks, as well as expanding into other types of drinks to reduce their reliance on sodas.
The decision to post calorie information follows the Supreme Court's decision this summer to uphold President Barack Obama's health care overhaul, which includes a regulation that would require restaurant chains and with more than 20 locations and vending operators with 20 or more machines to post calorie information. Last month, McDonald's (NYSE:MCD) announced it would begin posting calorie information on its menus nationwide.
There is no timetable for when all vending machines will be converted. Coke, Pepsi, and Dr Pepper often work with third-party vending machine operators; Neely said the companies will work with operators in those cases to convert machines.
Vending machines account for about 13% of sales volume, a figure that has remained relatively unchanged in recent years, according to Beverage Digest.
Although other factors such as a lack of physical activity and overeating also contribute, soda consumption is often identified for playing a role in rising obesity rates.
Last month, the New England Journal of Medicine published a decades-long study of more than 33,000 Americans that showed sugary beverages interact with genes that affect weight, meaning they are especially harmful to people who are hereditarily predisposed to weight gain.
Two other major experiments have found that giving children and teens calorie-free alternatives to the sugary drinks they usually consume leads to less weight gain.
Taken together, scientists say the results strongly suggest that sugary drinks cause people to pack on the pounds.
Bonnie Sashin, who works as a communications director for a nonprofit in Brookline, Mass., said she stays away from sugary drinks and "empty calories," limiting herself to a can of Diet Dr Pepper or Diet Coke about twice a month. But she thought the move to display calorie information on vending machines was a step in the right direction.
"I think it's a positive trend," Sashin said. "Anything that helps us be more educated about calories is a good thing."
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