Lumen - let the conversation begin šŸ˜‹

(Ian) #61

is that Biolayne on their web page?

LOL, nice pun by the way. :+1:

I think I would trust glucose and/or ketone meters more.

(Michael - When reality fails to meet expectations, the problem is not reality.) #62

Glucose and ketone meters donā€™t measure metabolic efficiency. Although aimed primarily at the SAD weight loss market, Lumen is a first relatively cheap user device to measure it directly. This is the first generation and I suspect that if its successful, we will get better reporting options with successive generations. Maybe eventually direct measure of RER, which would be enormously useful not only for ketoers, but many others.

(Bob M) #63

Can you take it multiple times per day? It might be interesting to see if it varies.

You ready to carb load so you can do the initial test?

(Michael - When reality fails to meet expectations, the problem is not reality.) #64

You can make a breath test as many times per day as you like. The device is basically just measuring CO2.

All Iā€™ve done so far is charge it and download the app for my iPod. I have to inquire, but it doesnā€™t look like thereā€™s a desktop app which is a bummer. No Iā€™m not ready yet to calibrate. This is of interest:

Question

Calibration day requirements

Answer

Itā€™s important to get a minimum of 5-7 hours of sleep the night before calibration day. The reason for this is that not getting enough sleep does affect your metabolism and what your body is burning as a source of fuel.

In addition, we strongly recommend taking your first calibration day breath after a minimum of 10 hours of fasting.

Again, this is because throughout calibration day you will be taking breath measurements at different stages of the day and at different metabolic scenarios, the first of which being ā€˜fastedā€™ which is important in order for Lumen to learn about your metabolism.

On calibration day we highly recommend eating high carb and low fat. This is because we want to understand each personā€™s unique metabolism and how it reacts to carbs. If you click ā€˜start calibrationā€™ you will be guided to take a breath measurement with your Lumen and thereafter you will receive your calibration day meal plan tailored to you.

Source

I have questions about this. Why does the device have to ā€˜calibrateā€™ anything? Does it or does it not measure CO2 against ambient air? If so, whatā€™s to calibrate? If not, then what exactly is going on? I have a strong suspicion that thereā€™s a lot of behind the scenes ā€˜cgiā€™ so they can build up a ā€˜profileā€™ for managing your diet - which is part of the plan. I donā€™t need nor want meal planning.

First calibration breath test is 10 hrs min fasted. To establish a baseline I presume. Since Iā€™m eating sub 15 grams of carbs per day, Iā€™m not going to ā€˜carb upā€™. Iā€™m going to eat my regular fare to my macro ratios and see what happens. I can always recalibrate if this results in weird stuff.

(Michael - When reality fails to meet expectations, the problem is not reality.) #65
(Bob M) #66

The high carb might be just to get a baseline. Maybe you need high carbs? Could this, for instance, produce a certain result?

Like this for instance, where high carb is about 1:

Maybe this varies by person, so maybe youā€™d get a 0.9 instead of 1? Then, the machine would know that 0.9 is (near) your maximum level.

(Michael - When reality fails to meet expectations, the problem is not reality.) #67

First impressions. The Lumen App sucks. I just want to take breath samples. I donā€™t want to watch young ladies riding bicycles and sitting around in cheery apartments. I just want to make a measurement. Period. The voice over is 100% unnecessary and condescending, like Iā€™m an idiot.

The ā€˜breathing techniqueā€™ is just as finicky as the Ketonix. But unlike the Ketonix, you only get 3 attempts and youā€™re done for the day. The app shuts down. All you can do from then is ā€˜practice breathingā€™! I tried to ā€˜calibrateā€™ my fasted breath this morning but didnā€™t measure up sampling-wise, so now Iā€™m prevented from trying again until tomorrow. It wonā€™t happen tomorrow, but maybe Sunday.

@ctviggen Good point about maybe using max VCO2 as the base line rather than min. I would point out, though, that the ā€˜calibrationā€™ starts with a measurement in the fasted state, so thatā€™s producing a min VCO2 value. Maybe the max is then calculated to give the range of possible values. If I can get the damn thing ā€˜calibratedā€™ weā€™ll find out, because I do not intend to ā€˜carb upā€™.

Finally, Iā€™m firing off an email to support to ask if they have a simple, nuts&bolts version of the app for us real bio-hackers who neither want nor need entertainment but just data.

(Bob M) #68

This makes logical sense to me. Of course, logic doesnā€™t always work with the body.

(Windmill Tilter) #69

This is what the RER of ā€œvery low carbā€ athletes look like at rest, and at varying stages of exercise intensity. Notably, they were fed 15% carbs which is way higher than any of us. They were compared against athletes eating a diet of >50% carbs. Unless you are currently sprinting while breathing into the Lumen, how could it possibly generate useful data? All of our RERā€™s are at around .75 pretty much 24hrs/dayā€¦unless weā€™re sprinting.

The only way the Lumen could show a deviation from this is if it doesnā€™t work. Am I wrong? What am I missing?

(Michael - When reality fails to meet expectations, the problem is not reality.) #70

@Don_Q As one whose level of exercise is probably going to stay at or not significantly much above ā€˜at restā€™ in terms of your chart, I think its usefulness might be: (1) Do I have to stay sub-20 grams of carbs per day to stay in predominant fat-burn mode; or what exact grams of carbs bumps me out, 40, 50, 75 or like spacebunny 100+; (2) What happens if I eat sub-20 grams of carbs per meal and the total exceeds 20 grams per day; (3) If I eat a couple of large DQ vanilla cones, how long does it take to return to predominantly fat-burn mode; (4) If I have a couple (or more) shots of gin, how long does the ethanol prevent fat-burn; (5) If I go out with the boys for pizza and beer how long does it take to get back into fat-burn mode. I can probably think of a few more, but thatā€™s a start. I donā€™t worry about ketosis, my primary concern after 3+ years is fat adaptation and how well thatā€™s going. How well do I cope with various fuel inputs? That sort of thing. Whether RER is .72, .75 or .79 is of less concern to me. Although Iā€™d love to have those numbers, I donā€™t think Lumen is going to give them to me.

(Windmill Tilter) #71

Gotcha. That makes sense. Youā€™re RER wonā€™t vary on a ketogenic diet, but it definitely will after pizza & beer!

Wouldnā€™t a ketone meter answer all of those questions more cheaply and precisely though?

(Michael - When reality fails to meet expectations, the problem is not reality.) #72

Ketone meter doesnā€™t tell me fat-burn. I can have a lot or a little on the meter, but still have no idea of how efficiently Iā€™m burning it. I know Iā€™m in ketosis most of the time and because I remain conscious and functioning relatively normally I must be burning ketones and fat efficiently. But Iā€™m a gadget guy so having a means of measuring that is attractive. Even a first gen device.

The pizza and beer is not going to happen, but other stuff might and Iā€™d like to know whatā€™s going on when it does.

Beyond Lumen, assuming itā€™s successful, others will follow and hopefully sooner or later we will have an unadorned RER hand-held meter.

(Windmill Tilter) #73

I can relate to that!

(Michael - When reality fails to meet expectations, the problem is not reality.) #74

Calibration

I managed to complete the ā€˜calibrationā€™ today. I ate my standard fair for the day, which included a total of 14.25 grams of carbs. At one of the breath samples after ā€˜dinnerā€™ the app queried whether or not I had eaten the recommended 11 ā€˜mealsā€™ (servings?) of carbs. I answered no which was followed a question of how many carbs I ate, to which I selected lowest option. Very little or something like that. There was no zero option or I would have selected that. Prior to each Lumen breath sample I sampled BrAce with my Ketonix to confirm I was in ketosis. Tomorrow my first Lumen day begins. I am very curious what the Lumen is going to report. And what happens when I eat some carbs.

(Polly) #75

Exciting times @amwassil. Looking forward to reading about your n=1 with lumen.

(Bob M) #76

Maybe not. I can (just did yesterday) eat ice cream and still be in ketosis a short while (a day?) later. Darn! All of my meters are at work, and I am at home, so I canā€™t test my ketones to see what they are.

(Michael - When reality fails to meet expectations, the problem is not reality.) #77

First morning

I was unable to take an RER reading first thing this AM. Somewhere partway through the questionaire my device and app lost contact with each other so I had to abort. Iā€™ll try again later after I get home from work. Iā€™m wondering why all the questions re my lifestyle: how long I slept, what time I went to bed and got up, did I eat all my carbs yesterdayā€¦ Does this devise actually measure anything or just do an esoteric calculation based on my answers to what is a very intrusive and to me pointless interrogation. Just measure the damn O2 in and the CO2 out, do the division and give me the result. Whatā€™s so complicated about that? Anyway, prior to the attempt I tested positive for BrAce with my Ketonix.

(Windmill Tilter) #78

It would be a really fascinating experiment to eat full sugar ice-cream, and track ketones + glucose + RER for every 20 minutes for the first 2 hrs. I donā€™t have a clue what would happen. Iā€™m not sure how quickly ketones would drop off, or how quickly RER would change.

When I did a ā€œmetabolic flexibilityā€ experiment a couple weeks ago after about a year of keto it was really fascinating. Just eating 100g of beans, which was around 60g net carbs, was like eating a jar of lightning. Prior to keto, I had struggled with hyperglycemia and hypoglycemia since my teens, so I have a strong frame of reference for what hyper feels like. This was off the charts. I was actually concerned it might be getting dangerous. It persisted for hours!

My theory is that because I do so much extended fasting, I have developed extremely strong physiological insulin resistance (the good, glucose sparing kind). Basically, my cells refuse to take sugar at the cellular level. At the same time, my pancreas barely even remembers how to produce insulin at the levels necessary to deal with such an event. The result is elevated glucose that has nowhere to go and just does laps through the bloodstream for a while.

In short, I think I was hyperglycemic while in ketosis for at least several hours, possibly more!

It would be fascinating to see which registered the transition out ketosis first, the Lumen or the meter.

(Ethan) #79

I just asked if being on a purely carnivore diet with NO carbs will affect calibration. I am not biting any bullets

(Ethan) #80

I just started measuring also. I am on a Carnivore diet of zero carbs. Letā€™s compare results as we move forward. I also sent a message to the Lumen makers about how calibration is affected if you just donā€™t eat ANY carbohydrates.