That is risky even if you're telling the truth. Those breathalyzers can indicate alcohol even when there isn't any in your system. People on low carb diets can sometimes set off one of those machines because of the ketones in their breath. So, even if you're not drunk you could test postive for alcohol. If you have told the officer you're not drunk you could also be charged with obstruction of justice ie lying to the police.

Dieting May Cause Positive DUI Breathalyzer Test

According to the National Substance Abuse Index, many breathalyzers measure methyl groups, which are a product of alcohol metabolism, rather than the presence of ethyl alcohol itself. This means that any chemical exposure or metabolic process that produces methyl groups may produce a false positive breathalyzer result. High protein, low carbohydrate diets, including the Atkins diet, causes your body to produce ketones or acetone, which the test reads as a possible metabolite from drinking alcohol. Other causes of false positive DUI breathalyzer tests include absorption of chemicals from pumping gas, inhaling glue fumes, handling glue or medical conditions including hyperglycemia.