I’ve been on Keto 5 months now so yes I am sure I am adapted, I can fast for 4 days without even feeling a flinch of hunger.
I have aproximately 17kg of body fat, at 26%
Your response makes sense also, that’s what I was assuming.
It’s harder to understand Ketosis and checking your ketones when you are fat adapted, sometimes the results are so confusing!
Maybe. I will test again now.
0.2 lol
I feel great though, I’m on hour 38, no sign of hunger yet.
It sounds as though you are okay. KCKO for now, and if you start feeling bad, or something weird happens, then re-evaluate. Let us know how things are going. :if there were a fasting icon, it would go here:
What do you think a fasting icon would look like? 
Im on hour 41 and Ketones are at 0.4 lol
What does your blood glucose look like?
Does your blood ketone meter do blood glucose too?
“…You will likely have some blood ketones in your bloodstream when your blood glucose levels are low, but they may not be at the levels that many consider to be ‘optimal ketosis.’ As shown in the chart below, if your blood glucose levels are at 4.5mmol/L or 80 mg/dL then you you might expect blood ketone levels to be somewhere between 0.3 and 0.7mmol/L. If your blood sugars are as 4.9mmol/L or 88 mg/dL your ketones might be somewhere between 0.4 and 1.1 mmol/L. …”
0.4
“…While measuring ketones can be interesting, they tend to be a much noisier measurement. As the glucose in your blood reduced your body will be forced to turn to your body fat stores, so you will increase your fat burning. Part of the reason that you may not see high levels of ketones in your blood though is that they are being used efficiently for fuel and not backing up in your bloodstream. So if you have limited funds for test strips and don’t want to be pricking yourself too often then I would focus on blood glucose levels. …” …More
PERCENTILE (BHB %ile)? WHAT THE HECK IS THAT?
Crowdsourced ketone and glucose values:
”… In late 2015 I pooled a range of data from myself and a number of people on the Optimal Ketogenic Living (OKL) Facebook group. After sharing this data initially, a number of other people sent me their data. Later, Michel Lundell from Ketonix agreed to share an extensive set of anonymised data for me to analyse.
I hope that this crowd-sourced data will help to provide more clarity about optimal ketone levels in a similar way to Dr Bernstein surveying the glucose metre sales reps helped to provide a better understanding of what normal ketone values are.
The chart below shows the sum of the blood glucose and ketones (i.e. total energy) from nearly three thousand data points from a broad range of people following a low carb or ketogenic dietary approach.
On the right-hand side of the chart, we have a high energy situation from both glucose and ketones. While not as extreme, high energy situation is similar to someone with Type 1 diabetes with high glucose and high ketone levels due to inadequate insulin. High levels of energy in the blood causes the pancreas to secrete insulin to hold the glycogen back in the liver and stop lipolysis (i.e. the release of fat from storage) until the energy in the bloodstream is used up.
On the left-hand side of the chart, we have a low energy situation. These people do not have too much energy floating around in their bloodstream. They are also likely insulin sensitive and can easily access their body fat stores for fuel.
As shown in my fasting ketone data above, we may see high blood ketone levels when we go without food for an extended period. However, trying to replicate high ketone levels with high levels of exogenous ketones or an oversupply of dietary fat will not provide the same positive benefits as endogenous ketosis.
Based on this crowd-sourced data it seems the body tries to maintain a blood glucose level of around 4.9mmol/L and a blood ketone level (BHB) of around 1.5mmol/L. The table below shows this data in terms of average as well as the 25th percentile and 75th percentile points. …” …More
I have to say that that data is suspect. Unless you get data from random people, you don’t have good data. Those people giving him data are a very select subset of people who actually take data, for instance.
Also, my morning reading today was 0.9 mmol/L BOHB and 96 mg/dL (5.3 mmol/L) or 6.2 on that scale (about 36 hours fasting). After a 50+ minute workout (no food, only coffee), the results were 0.3 mmol/L BOHB and 115 mg/dL (6.4 mmol/L), or 6.7 on that scale. Based on that graph, it appears I’m killing myself. But I have no control over this, and it’s just the way my body is right now. I can’t make my blood sugar go down if I’m fasting. It’s not possible. I only get into low blood sugar in the evenings (even if I eat low carb), as my blood sugar pattern is that my blood sugar nadir occurs around midnight, then rises until about noon or so, then decreases all day long. Food intake adds small bumps to this pattern, but this is my pattern, determined using a continuous glucose monitor. My last HbA1c was 5.0, and this is about as low as it’s going to go.
So, that graph is fearmongering.
Maybe you should discuss this with your treating physician?
I know nothing about your individual health conditions to comment either way!
Just a general exchange of information, read it or don’t read it, the choice is yours!
If your looking at the skull and crossbones that means it MAY NOT be a endogenous state of ketosis and has nothing to do with death (unless your blood ketones are too high 10+)!
My gut is telling me that you maybe dumped some ketones from the crap eating, so the body had to build them back up, but that you’re also becoming well adapted now, so the body is processing ketones more efficiently. I was well adapted probably around the 6 month mark. I’ve also never been able to go above 35g of carbs without concluding that I likely dropped out of ketosis (diabetic, so basing my thinking on glucose reading behavior instead of a ketone reading.) I noticed from tracking that though that during fasting my average glucose consistently increased a few points. It could be a combination of the crap eating having more carbs + a glucose bump from the fasting. If I know I probably got knocked out of ketosis or skirted a line, instead of fasting, I go back to < 20g carbs with high fat for a few days. My body seemed to switch right back over once well adapted; for me about 24-48 hours. Also, fighting a cold or something can really throw things off. I would imagine that if sick or fighting allergies that ketones would be used at a faster rate to provide energy to the fight.
The measurement of the ketones is making you nuts. If you were getting nutty results like this from the scale, everyone would tell you to weigh less frequently. 90% of the posts about ketone measurements is people bother and confused by their readings, with no actionable correction suggested.
This is why I tell people not to chase ketones. It only makes most people nuts.
That was an amazing amount of information, thank you @atomicspacebunny
I am currently at 60 hours fasted and just read 0.4mmol but it may be a dawn reading.
I don’t really think I need this blood ketone monitor anymore.
It just drives me batty.
I know I am on the right track lol, I feel great today.
Thanks for all the wonderful information!
I have gently been flexing this fasting muscle of mine.
I started off with normal 24s, 36s, 48s, 60s, 72 hours, I do wonder if I can get to 90 or 100.
I’ve lost 5 pounds so far, with a total loss of 32lbs.
I am on the final stretch!
But the elephant in the room is Breath Acetone (BrAce) which is a true measure of one’s current fat metabolism levels. A cheap breathalyser will indicate if one is excreting acetone in the breath. A more expensive acetone meter will give a well calibrated reading. In my opinion measuring blood ketones is futile unless one has Type 1 diabetes.
In relation to ketosis our bodies are like automobiles. Blood ketone (BOHB) measurement results equate to the fuel gauge which reflects the amount of gasoline in the tank (blood stream). Breath acetone (BrAce) is the speedometer reading indicating the actual speed of fat metabolism at the time of measurement.
My BOHB and breath acetone readings don’t appear to be correlated - at all. Left is BOHB, right is breath from ketonix (first version):
if your tissues are rapidly uptaking ketones you will see a low measurement. this happens post exercise as well.
I would like to ask for some research to back up this assertion, please. Any chance you could provide links to some papers?
The only paper on the topic of measuring acetone in the breath that I have been able to find on PubMed is one trying to establish that measuring acetone in the breath was a reliable marker for the serum β-hydroxybutyrate level. The paper wasn’t entirely convincing, and it was by a researcher who worked for a a company that manufactured breath analyzers, and the company paid for the study. I believe the company was trying to make a case for its product.
Nevertheless, the claim that breath acetone is a reliable (and cheaper) marker for serum β-hydroxybutyrate is a far cry from saying that excreted acetone is a true measure of fat metabolism. If there is any research out there to support the latter assertion, I’d be very interested to take a look at it.
Paul, we’ve been here before:
Maybe that will suffice for you again?
If I didn’t know you better, I’d say you do seem to do a pretty good “Dog in the Manger” impression in relation to the topic of the validity of measuring Breath Acetone versus measuring blood BOHB.
You’ll also notice that I provided you with the article that you are now quoting from PubMed.
Many people on this forum use breathalysers as a cheap tool to confirm that they are in Ketosis. Why knock something that works because there is no corporate behemoth promoting them for “off-label” use as there is no profit in it and that’s why there is not much published research.
I have been using such a device for over a year and I find it truly informative. It keeps me true to the Keto WOE without measuring macros and obsessing about making progress or not. I measure Breath Acetone, I know whether I’m in Ketosis or not and if so what level of Ketosis; Nothing could be simpler or more satisfying. Compare that with what seems like 2-3 threads a week on this forum about people having problems understanding their Blood Ketone levels.
As I said in both threads, I don’t find that study convincing. Firstly, I don’t know of any mechanism for measuring fat metabolism directly except RQ, and that’s not something that we can do at home. (And even RQ only tells what proportion of fat versus glucose is being metabolized, not the quantity of either—or so I understand.) Secondly, that study makes several assumptions that don’t appear to be justified, so to say that exhaled acetone is a “more accurate” measure of fat metabolism than measuring serum BOHB seems to be a wild leap, in the absence of any other studies. Particularly when the only claim that one study makes is that it is a reliable marker for serum BOHB levels.
If you had said it was a “cheaper, reasonably reliable substitute” for measuring BOHB, then I’d certainly have gone along with you, because it’s an assertion that is quite in line with the available research. But even that assertion relies on the assumption that the body is producing enough acetone to be able to waste some in the breath before it gets used, whereas BOHB remains in the bloodstream until use and doesn’t get wasted. For that reason, I would consider it an ultimately more reliable, albeit much more expensive, marker for ketone production than either urinary acetoacetate or breath acetone.
Personally, I don’t measure my ketones at all. If I really needed to know how much I was producing, I’d buy a blood monitor by preference, and hang the expense. If I were to give my inner Scotsman free rein, however, a cheap breathalyzer is the way I’d go, for sure.
(Of course, the question of how many of the ketone bodies produced by the liver are actually getting used is a whole other matter, which we really don’t need to go into, lol! It sure would be nice to be able to measure that, however.)
