By Andrew M. Seaman (Reuters Health) – People who mix alcohol and diet drinks end up with more alcohol on their breath, according to a new study. 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 write in Drug and Alcohol Dependence. Prevention materials should include this information so people know that by trying to avoid some extra calories in a mixed drink, they risk having higher breath alcohol concentrations, write the researchers, led by Amy Stamates of Northern Kentucky University in Highland Heights.