Can I get a false positive with a breathalyzer?

#1

I’ve been in ketosis for about three months. I’ve been eating more carbs the last couple weeks, including a couple pints of ice cream. I expected to read a zero on my meter later or the next day but I have consistently seen the same numbers, .3 to .5. Is there something I could be doing to get a positive reading on my meter when I am not in ketosis. I am wondering if I should trust the meter.

I am a very active 53 year old and the pee strips don’t work for me any more unless I am fasting. Thanks.

(Lesley) #2

Could it be that you were knocked out of ketosis for several hours during the night and then went back in by the time you tested again!?

I’ve found that when I’m knocked out by something I’ve eaten around 6pm that I’m not knocked out until around 5am the next day then usually back in by 2pm at latest. Just a thought!

#3

That’s possible. I usually test a couple hours after carbs and then forget about it until the next day. I like to test before I start eating each day to see if I need to be more strict. I am usually pretty good after a slip since I often feel bad for a while afterwards. It seems like eating nothing or eating just butter helps me feel better sooner. That and moving around instead of staying on the couch.

(Lesley) #4

I know how you feel after a slip. Thing is not to be too hard on yourself and just get on with it again as you have been :slight_smile:

#5

Ugh, be careful with that… my darned breath meter steered me wrong and I ended up completely falling out of ketosis, had to become fat adapted all over again. I was testing my breath a few times a day and things were always on track with what I was eating. When I was confident that I was fat adapted I experimented to see how high I could raise my daily carbs and still stay in ketosis, so every few days I would increase my carbs and check my meter. It always told me I was still in a good range. So I would raise my carbs more. Still in ketosis. I raised a little more… still in ketosis. It was good news to me but I started to wonder how this could be possible so I did a total pig out for a few days (candy, chips, pasta, etc.). I STILL showed in ketosis. I knew that couldn’t be right so I ordered a new meter. Yup, I was at zero. I probably had been for weeks.
Threw away the meters and ordered a blood monitor.

Oh, and if you ingest any keto-friendly treats with sugar alcohols in them, your breath meter will show you a very high reading. I think it was Swerve that would always cause my monitor to beep with off the chart readings.
Sue

#6

Thanks. This is what I’ve been suspecting. I think I’ll try a new meter.

#7

Yep, new meter’s reading zero, old one .5.