IT'S the guilt-free option that could land you a guilty verdict.
Australian research teams studying the metabolism of soft drinks have found that mixing artificially sweetened beverages with alcohol results in higher breathalyser readings - ones which could land drivers in court.
Though the survey has only covered small study groups so far, scientists in both Australia and the US have examined links between diet drinks and booze.
The results show a disparity between conventional soft drinks and diet spin-offs.
Chris Irwin, a PhD candidate at Griffith University, examined the way the body handles alcohol and dehydration. His study of 16 people repeatedly tested the same group to investigate the link between soft drinks and blood alcohol.
It found that artificially sweetened drinks provided an average breath alcohol concentration of 0.065 per cent. This compared with 0.045 per cent for conventional sugary carbohydrate-laden drinks - just below the legal driving limit of 0.05 per cent.
The results could have wide-ranging ramifications.
"There are implications for people that might go and have one or two drinks and if they're choosing drinks that have diet mixers, it might put them over the limit," Mr Irwin said.
"It may make a big difference in their blood-alcohol limit and put them at risk of driving under the influence, while if they have a carbohydrate-based drink with alcohol they could be under the limit."
The difference is linked to how the body processes drinks. Sugary beverages take longer to break down, which slows the release of alcohol into the bloodstream.
A spokesman for the Australian Beverages Council said four out of the five best-selling soft drinks in Australia were artificially sweetened. But it was not possible to say what percentage was sold in licensed venues.