Mixing booze with slimline drinks could make you more drunk than using standard mixers, research has revealed.
A study found that people who drank vodka mixed with diet soda had higher alcohol concentrations on their breath than those who drank the same amount of vodka mixed with regular soda.
Researchers believe people should be made aware that by trying to avoid some extra calories in a mixed drink, they risk having higher breath alcohol concentrations - particularly over the Christmas period.
Researchers from Northern Kentucky University observed 10 men and 10 women (aged 21-30) who had consumed five different mixed beverage combinations over five sessions.
The drinks contained varying amounts of vodka and either diet or regular sweetened mixers. One drink was just a regular soda with no alcohol at all.
The researchers then measured the alcohol concentrations in the participants' breaths for three hours.
They found breath alcohol concentrations were about 22% higher when vodka was mixed with diet soda rather than regular soda.
There were no differences in the results by gender, however researchers say the findings might be more relevant to young women, who are most likely to use diet beverages in their mixed drinks.
Co-author of the study Cecile Marczinski told The Telegraph: "While all alcohol consumers should be aware of this phenomenon, it appears more likely that women would select alcohol beverages with a diet mixer given that they are more likely to be conscious of calories in their drinks.
"Young women may be particularly vulnerable as they frequently use diet mixers with alcohol and they also restrict food intake when drinking to control calorie consumption and, ultimately, body weight."
The research was published in the journal Drug and Alcohol Dependence.