FRIDAY, Jan. 9 (HealthDay News) -- If you're like many Americans, soda and coffee drinks have become a staple of your daily diet.

But the findings from a new study may make you drop that super-sized, sweetened beverage.

Published in the January issue of The American Journal of Clinical Nutrition, the research found that people are now drinking almost 50 additional calories of sweetened beverages daily compared to two decades ago, for an average of about 300 calories daily coming from such drinks. So, even if you have the exact same diet as you did 20 years ago and your activity level hasn't changed, those seemingly harmless 50 extra daily calories could cause you to pack on an additional five pounds every year.

"People are taking in enormous amounts of calories in liquid form," said study author Sara Bleich, an assistant professor of health policy and management at the Johns Hopkins Bloomberg School of Public Health. "If you're looking for an easy way to lose weight, just stop drinking soda and other sweetened beverages."

Cutting 300 liquid calories from your daily diet translates into about a 2.5 pound weight loss each month.

For the study, Bleich and her colleagues compared data from two national surveys that are part of the National Health and Nutrition Examination Survey (NHANES). One survey covered 1988 to 1994, and the other ran from 1999 to 2004.

The first study included 15,979 adults over age 20, and the second included 13,431 U.S. adults. All completed 24-hour dietary recall information, including whether or not they had consumed a sugar-sweetened beverage. For the study, sugar-sweetened beverages included soda, sport drinks, fruit drinks, punches, low-calorie drinks, sweetened tea and other sweetened drinks.

The percentage of adults who drank sugar-sweetened beverages increased from 58 percent to 63 percent, and the average daily caloric intake from sugar-sweetened drinks increased by 46 calories a day, according to the researchers.

Young adults drank far more calories from sugar-sweetened beverages than did the elderly, with young blacks consuming the highest percentage of sugar-sweetened beverages.