Lumen - let the conversation begin 😋

(Michael - When reality fails to meet expectations, the problem is not reality.) #1

Still vaporware, but what do you think, potential or useless gimmick. Let the conversation begin:

The science (a bit):

Home page:

How long until you are OUT of being fat adapted?
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High Acetone Levels In Breath After 2.5 days of Keto
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Is this bacon ok?
(Bob M) #2

It seems interesting, although their materials place too much emphasis on carbs (Phinney and Volek showed glycogen replacement on a keto diet).

(Michael - When reality fails to meet expectations, the problem is not reality.) #3

I suspect the first generation of personal, mobile measuring devices are going to be focused around carb tracking. What I like about Lumen, although it’s targeting the mainstream CICO world, it still shows fat measurements. As of today, it is scheduled to begin shipping in July. So we might actually have it soon. I’d like to compare it to the up/downs I get with Ketonix. My guess is that RER/RQ are more stable and more easily measured simply because the concentration of both CO2 and O2 are so much denser than acetone.

(Karen) #4


(Michael - When reality fails to meet expectations, the problem is not reality.) #5

OK, I’ve just done something I’ve never done before! I bought and paid for a product that won’t even ship until November 2019. Even paid through Indiegogo, GULP. That’s how impressed I am with the potential of this product. I will post any order updates I receive during the interim.

(Empress of the Unexpected) #6

It sounds fascinating but I don’t think the technology is there yet. And not sure what it has to do with keto. With the constant switching between burning fat and burning carbs. It would be interesting but we all know how to eat here so I wouldn’t think it would be necessary. But I still would like to hear reports on it.

(Michael - When reality fails to meet expectations, the problem is not reality.) #7

@Regina Do you know something I don’t? If so please provide a link. I have until July 7 to cancel my payment to Indiegogo.

Some of us like the bleeding edge where we discover stuff we never expected. No one knew about nutritional ketosis until some brave heart decided to try it to see what happens. Doctors no doubt told him he would die a horrible death. No one believed Stefansson until he spent a year in a lab eating only meat and fat. Not only did he not die, as expected, he and his companion thrived.

You “know how to eat here” only because someone tried a lot of different alternatives until we got it more or less right. :wink:

Is Keto a cult or groupthink?
(Empress of the Unexpected) #8

Of course not, I have no idea what I am talking about. Other than the fact that even the BG and ketones have quite the margin of error. But I am confused by the fact that the video for the device seems to encourage periodic carb ups depending on ones activities. But I can’t wait to hear about your experience. How much was it? I could t find the price

(Michael - When reality fails to meet expectations, the problem is not reality.) #9

Thanks. BG measurements are useful because glucose concentration in the blood directly determines a number of health parameters. Insulin (and glucagon!) measurements would also be very useful, but as far as I know there are no home devices available for it.

Ketone measurements, on the other hand, are a proxy for fat metabolism and even then only measure β-hydroxybutyrate concentration, the somewhat more stable storage form of acetoacetate, which is the actual ketone energy packet. β-hydroxybutyrate concentration does not tell us how much fat and/or ketones are actually being utilized.

Breath acetone (BrAce) measurements reflect the concentration of acetoacetate. This because BrAce along with CO2 are the resulting products of acetoacetate breakdown and utilization. BrAce is a better indicator of actual fat burn of acetoacetate, but the concentration in the breath is so dilute that it is very difficult to measure accurately. Also, the amount of acetone produced varies markedly and rapidly.

Yes, all of the above change constantly because our metabolism is a very dynamic system. It responds to inputs/outputs continuously, minute to minute.

A non-invasive device that accurately measures RER determines the ratio of carb and fat burn. No need to estimate fat burn based on the measurements of moving proxy targets! The possibilities and potential for this are very great indeed. For example: do you really need to eat sub-20 grams of carbs to stay in ketosis? What if you eat 50 grams and still have an RER of .7 or .71? That would be good to know, don’t you think? Or the opposite. Someone thinks “I can eat 50 grams of carbs and I’m still in ketosis”. Then discovers his/her RER is .8.

(Empress of the Unexpected) #10

I agree.

(Michael - When reality fails to meet expectations, the problem is not reality.) #11

I’ve received a couple of emails since ordering. My payment went through, no surprise there! Most recent email from Indiegogo came this morning stating that the very earliest ‘supporters’ will start getting their devices this month with the remainder of the ‘very early’ supporters getting their devices through out September. I’m an ‘early supporter’, although not particularly ‘very’. Hopefully, I’m still on track for a November shipment. We’ll see.

(PJ) #12

I’m glad you’re doing this, since I am poor right now. I hope you’ll share all the details with us. :slight_smile:

(Michael - When reality fails to meet expectations, the problem is not reality.) #13

I certainly shall!

(Michael - When reality fails to meet expectations, the problem is not reality.) #14

Status Update:

Hi Michael,

Thank you for your patience.

The super early bird and early bird backers will be shipped in two batches, the first of which started in September and will continue until the end of November. The second batch will begin shipping during December until the end of January.

Based on your pledge and region, your Lumen is included in the second batch of shipping.

We know that for many of our backers, the wait to receive their Lumen device has been long. While new users will need to pay a subscription fee, as a token of our appreciation for the faith in Lumen as an early backer, we announced that all Lumen Indiegogo backers will be provided with a FREE lifetime membership to the Lumen app.

If you have any other questions, please do not hesitate to reach out to us.

Have a happy and healthy day,

Mike's Excellent Zero Carb Beer Adventure :beer:
(Jenna Ericson) #15

I was wondering about this…was thinking about asking for it as a Christmas present from my husband, but on their website after you click “buy” it says “Due to high demand, orders made today will ship in March” :frowning:

I’m curious to hear about it when you get it. I was a little confused about how it works. I thought that in order to get your RQ and know if you are burning fat or glucose you need to know the ratio of how much oxygen is going into your lungs vs CO2 out. Their website seems to only talk about measuring CO2 out, so I’m not sure how they calibrate it to you as an individual. Looking forward to your review!

(Windmill Tilter) #16

I’m not really sure I understand the use case for this if someone is on keto. I own an indirect calorimeter that also measures RER/RQ but I never bother to use for function. All I’m interested in is RMR and VO2 max. Also, the RQ readings during extended fasts were nonsense; the algorithms weren’t programmed for that.

If you’ve been on keto for a while you’re pretty much burning fat. You already know your RQ! I’m not an expert on the subject obviously; what am I missing? Is it for keto athletes that do carb cycling or something?

(Michael - When reality fails to meet expectations, the problem is not reality.) #17

Fat burn. Ketones are only an indirect measure of fat burn and fat adaptation. They don’t tell you how much and how efficiently you’re utilizing fats for fuel. I think using RER/RQ is probably a better way to determine both fat burn and efficiency. There is also a wide range of opinions and claims on this forum about how much carbs one can consume and remain in ketosis/fat burn. The device will help to pin down that controversy, I think.

(Michael - When reality fails to meet expectations, the problem is not reality.) #18

Yes, but the more important ratio to measure is CO2 : O2 out. Since burning fat produces less CO2 per unit of O2 the ratio of both in exhaled air can be used to determine RER. See this:

(Windmill Tilter) #19

If you"ve been on keto for at least a week your RER is between .7 and .8, and it stays there until you fall off the wagon. The chart would basically be a squigly line between .7 and .8 for as long as you stay under 20g carbs per day wouldn’t it?

The other problem is that the algorithm will probably have been programmed with an emphasis around an RER of 1.0 under the assumption that people eat carbs. My indirect calorimeter has this problem. I’ve gotten back readings over .8 while 80hrs into an extended fast. Not humanly possible. It cost $12k and had just been recertified by the lab. Even so, I don’t think the results are reliable at the lower end of the scale. Maybe the Lumen will be better, if so that would be very interesting.

My understanding is that the utility of RER increases as carbs do. If you’re a DASH diet carb burner and fat is 5% of your dietary calories, and you’re trying to lose weight, RER will tell you a little. If you’re on keto, it won’t be able to tell you whether consuming bodyfat, muscle or dietary fat & dietary protein. Or does the Lumen claim to do so? Is there some other biomarker it tests for that allows this?

(Windmill Tilter) #20

That would definitely be interesting. What calculation would you use to do this? I’m a bit of an RER noob, but I do love to experiment. Is there a paper you can link?