Coca-Cola and Pepsi, the nation's top beverage makers, have both announced that they will begin disclosing the amount of caffeine in each bottle or can it sells in the U.S.
The Food and Drug Administration requires caffeine to be included in the list of food product ingredients, but it does not require the quantity to be specified.
The non-profit U.S. Center for Science in the Public Interest has been pushing for such a move for over a decade and says it applauds the decision.
Public Interest spokesman Michael Jacobson says people are concerned about the amount of caffeine in their products.
Scientists say consuming more than about 400 milligrams of caffeine a day can cause anxiety, sleeplessness, headaches, nausea and even heart problems. A 12-ounce soda typically has 30 to 55 milligrams of caffeine.
Jacobson says the Pepsi label will read "Caffeine content: 25 milligrams per eight ounces."
The announcement comes the same week as Pepsi confirmed reports that the company is planning to release a higher-caffeine drink, called Diet Pepsi Max, later this year.
The Coca-Cola Co., the world's largest beverage maker, said Wednesday it will put caffeine content information on the labels of all of its drink products distributed in the United States that include the ingredient.
The Atlanta-based company said its move (which was made public after Pepsi confirmed its plans) was voluntary and part of an industry initiative.
Coca-Cola said it already has included caffeine labeling on its Full Throttle and Enviga products. It said it will roll out the new labels on its other brands, starting with cans of Coca-Cola Classic in May, and expanding to other brands and packages during the remainder of the year.
The time at which the revised labels reach store shelves will vary by brand and region as U.S. bottlers use up existing inventories of packaging, Coca-Cola's North America division said in a statement.
A spokeswoman for Coca-Cola said the expanded caffeine labels will not be placed on Coke products distributed outside the United States.
Word of the new labeling practice comes just days after a New York City councilman announced plans to introduce a resolution in favor of caffeine-content labeling on foods and drinks.
Councilman Simcha Felder, who admits he drinks several cups of coffee a day, announced over the holiday weekend that he planned to introduce the resolution to pressure the federal government to require the more detailed labeling. He plans to introduce the resolution Feb. 28, the next time the full council meets, an aide said.
Felder, a Brooklyn Democrat, has said he knows the City Council has no authority to force companies to provide the information on their products, but he wanted to put the city's voice behind a movement to urge the FDA to require companies to provide caffeine quantities.
"I am certainly encouraged by the initiative that is being taken from within the industry," Felder said in a release.