NEW YORK — Americans cut back on soda at an accelerated pace last year, extending a slow retreat from the category that began nearly a decade ago.

U.S. sales volume of carbonated soft drinks fell 3 percent in 2013, according to a report released Monday by Beverage Digest, an industry tracker. That represents a steeper drop than the 1.2 percent decline in 2012 and brings total soda volume to the lowest level since 1995.

The latest numbers underscore the daunting challenge Coca-Cola and PepsiCo face in turning around the category, despite their plans to intensify marketing and introduce versions of their flagship sodas made with natural, low-calorie sweeteners.

While carbonated soft drinks still represent the biggest category in the beverage industry, alternatives such as energy drinks and flavored waters have slowly chipped away at the popularity of longtime favorites like Coke, Pepsi and Dr Pepper.

Soda’s image has also taken a beating, with public health advocates blaming it for fueling weight gain.

Even diet sodas are suffering. Last year, for instance, sales volume for Diet Coke and Diet Pepsi suffered steeper declines than their full-calorie counterparts.

Overall, Coca-Cola fared better than rival Pepsi and saw its soda volume fall 2.2 percent, according to the Beverage Digest. PepsiCo, which also makes Mountain Dew, saw volume fall 4.4 percent. That was despite the company’s stepped up marketing for Pepsi.