TUESDAY, Feb. 5 (HealthDay News) -- Calorie counters, beware: Drinking diet "mixers" with alcohol intensifies the effects of the booze, according to the findings of breathalyzer tests.

Preliminary research on the use of different mixers, such as juice, soda or diet soda, suggests that diet soda might increase breath alcohol content more than higher calorie sugary beverages.

"The key thing is to be aware of this phenomenon," said study author Cecile Marczinski, an assistant professor in the department of psychological science at Northern Kentucky University in Highland Heights.

"People tend to think that cutting calories is important, but when you're drinking alcohol, calories help slow down the release of alcohol to your liver and brain," Marczinski said.

Breath alcohol concentration, which is what police measure to determine if someone has consumed more than the legal limit of alcohol, is affected by different factors. Food in the stomach can lower breath alcohol concentration by up to 57 percent compared to drinking on an empty stomach, according to background information in the study.

Because many people are concerned about their weight, particularly young women, the researchers wanted to see how a drink mixer might affect breath alcohol levels.

For the study, released Feb. 5 online in Alcoholism: Clinical and Experimental Research, the researchers recruited eight males and eight females, average age 23, to attend three study sessions. At one session, they drank vodka mixed with regular Squirt, a soda. At another, they drank vodka mixed with diet Squirt, which is artificially sweetened with aspartame. At the final session, a placebo session, they drank regular soda with a small amount of alcohol on the top of the drink to create the smell of booze.

At each session, the study volunteers drank the equivalent of three to four bar drinks in a short period of time, said Marczinski. Breath alcohol content was measured eight times in the three hours following the drinks' consumption.

Breath alcohol levels peaked 40 minutes after the study volunteers had their drinks. When the alcohol was mixed with regular soda containing sugar, the peak breath alcohol level was just under the legal limit at 0.077. But for diet soda drinkers, the peak was at 0.091, which is above the legal limit for driving a car.