Confused about blood test v. urine test

(Debra Moore) #1

Here’s kinda a new one. I’ve been doing keto for about four months this time. Was keto for several years before and successfully lost 30 lbs.

I’ve never had consecutive great keto readings - in the morning it’s around .3-.6, then I do IF and it gets over 1.0 but goes back down after eating.

But for the past week, it’s been 0.0. Even though I do IF, even though I’ve been extremely careful about staying under 20 grams of carbs, even after IF + 45 mins. of HIIT.

I just thought I was having problems after a small cheat meal on Super Bowl Sunday where I had some clear alcohol and a couple of tacos. But it’s weird.

Also, here’s the rub - I also have urine test strips and on those, I get the “large” readings after IF. Even after I eat, I get the small reading. It’s never negative, though.

Are my blood test strips bad? I have two different machines because I misplaced one and bought an identical one, and both machines say 0.0.

I can’t think of what’s going on. Any ideas?

(Bob M) #2

That is interesting. I can say that I don’t understand the differences between breath, urine, and blood ketones in the way the body uses and/or produces them. But when I was testing all 3, the “worse” one was urine, in the sense that I could get a zero or very low there but get much higher breath or blood ketones. I was never able to get a clear indication of a pattern though, even for blood and breath ketones. That is, they often did not agree.

What you’re describing is weird though. You wouldn’t happen to have bought a test bottle, would you? That would be useful, as then the machine should say whatever the test bottle says it’s supposed to say. (Side note: I buy test bottles for ketones and blood sugar…and never use them. Or at least remember using them only once, when I wanted to see if the machine was reading correctly, and it was.)

But my guess is bad strips. Or strips that don’t match the machine for some reason.

(KM) #3

Urine strips can also go bad, but from what I’ve seen, in the opposite way - they stopped recording ketones or appear a rather nondescript paler color.

(Peter - Don't Fear the Fat ) #4

Not sure about the blood test (I’ve never used one) but the urine tests are pointless. They worked for me initially but after a while don’t give a true measure, I’m 100% zero carbs now and the strips still say no ketones when I’ve obviously have plenty.
If your under 20g and feeling good … your making and burning ketones.

(Bob M) #5

To get zero on blood ketones is tough if you’re at all low carb. I have some 60% chocolate bars I bought to make a low carb dessert. If I make the dessert (with allulose, cream, etc.) and put into containers, the carbs won’t be too much per serving.

But this weekend, we had a snow storm and lost power for 2 days. I had to put 100 pounds (about 50kg) of salt on our driveway to be able to drive on it, then I went out for hours chipping away at the ice. We had trees come down, so we were cutting up tree limbs and dragging them off the property. They were super heavy because they were coated with ice. I fell twice due to the ice, and worked a long time keeping the house running on our small generator and clearing everything.

When we finally got power, my wife and I went to a new “Mexican” restaurant where I had some soup and 4 small corn-based “tacos”, then came home and ate quite a bit of chocolate from the bars (instead of keeping them for the dessert)…and still had 0.1 mmol/l blood ketones this morning.

So, to get zero on blood ketones is possible, but unlikely, if you’re eating keto or near there.

(Cathy) #6

My understanding is that blood ketones are a different type of ketone than those measured in urine. The blood ketones are more accurate as the urine ketones are a picture of what was - given they are waste.

Many people tend to get low levels and even negative on the urine test over time because their bodies become more adept at using the ketones available and don’t through them off in urine.

(KM) #7

How can you have “negative ketones”? Is that like anti-matter? :laughing:

(Doug) #8

It’s where you have to make some ketones just to get back to zero.

(B Creighton) #9

I’m with Kib. If the urine test strips are old, they are probably no good anymore. My wife left the lid off of mine one time, and now they show zilch when for instance back in Dec, I had a blood ketone of 1 according to Quest labs.

(Bob M) #10

I was assuming “negative ketones” meant that a ketone reading was negative, that is, zero ketones.

The urine readings can have too many variables, including how hydrated you are. When I started out, I used to get really high urine ketone readings after cycling a few hours. I assumed I was dehydrated to some extent.

(Debra Moore) #11

OP here - the mystery is solved! Apparently the strips were bad, which is weird because the ones in that same canister were completely fine the day before. I have no idea what happened to them. They didn’t get wet and they didn’t expire. They just…stopped working. Weird.

Anyhow, I bought another batch of strips and everything is fine now! :slight_smile: Thanks for all the input!

(Peter - Don't Fear the Fat ) #12

I wouldn’t rely on them too much. If I understnd correctly they measure the ketones you don’t use, the ones that you consider waste, however, once your well adapted you ‘waste’ fewer and use more … resulting in less waste, hence the strips show no ketones and that’s is kind of true because you’ve used them for energy!

(Luke) #13

Hi check the machine settings mine does blood glucose for diabetes as well as the keto test and has to be on the right setting. Cheers.

(Jane) #14

These are a life saver! I was feeding my neighbors cat while they were on vacation during an ice storm and couldn’t even stand up when I got out of my car.

I had these with me just in case, slipped them over and boots and walked right up to the front porch.