CHARLOTTE, N.C. (CBS Local) — A former American Airlines flight attendant who was fired after failing a breathalyzer test says his ketogenic (keto) diet — not alcohol — was responsible for the false positive.

Andre Riley, who had been a flight attendant with American Airlines since 2012, says he was fired last year because he blew a .05 on a breathalyzer.

“I wasn’t drinking. I wasn’t doing anything, just because I changed my diet,” he told WJZY.

The keto diet, which has become a trendy weight-loss diet in recent years, encourages the body into a state of ketosis, meaning it burns fat instead of carbohydrates for energy. It was initially designed to help people who suffer from seizure disorders.

Riley claims to be on the keto diet as a treatment for an autoimmune disease he calls “Jared Disease Autobureau Syndrome,” according to WJZY.

Dr. Ryan Lowery, who specializes in ketogenic diets and runs Ketogenic.com, says the diet can impact the way your body breaks down food, causing incorrect test results.

“You create something known as acetone. With acetone some of that gets released as something known as isopropyl alcohol,” he said. “Some breath analyzers that detect for duis and things like that aren’t able to differentiate between ethanol alcohol and isopropyl alcohol.”

Riley admits he first failed a breathalyzer test in 2013 in an alcohol-related incident. Department of Transportation policy bars anyone who fails more than once from working as an attendant for any airline.

But Riley says this time is different and he’s going to takes on the DOT and American Airlines to clear his name and get his job back.

“I don’t want to be punished and take consequences for something that I didn’t do,” he said.

American Airlines has declined to comment on the case, according to Fox News.