Using CGM Data to Crack the Weight Loss Code

Feeling stuck despite your best efforts? AI-powered analysis of your unique blood glucose response could be the key to overcoming stubborn blocks.

Thomas DeLauer
Thomas DeLauer
— Signos
Health & Fitness Lifestyle Writer
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Reviewed by

Thomas DeLauer
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Updated by

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Science-based and reviewed

April 23, 2024
May 24, 2022
— Updated:

Table of Contents

I Tracked my Glucose for 30 Days (& This Is What I Found)

Sometimes I have a weird response to monk fruit where it actually spikes my insulin and it drops my blood sugar down, whereas my wife doesn't have the same response. There's no way that I  could have ever been able to acquire that data if I wasn't monitoring my blood glucose utilizing  a continuous glucose monitor. This is what I have learned about blood glucose, blood glucose drops, and stable glucose levels — all while wearing a CGM. 


Blood glucose is necessary

The big important piece we have to remember above all else is: you will always have a level of blood glucose1. Whether you are keto, whether you are fasting, it is the job of your body to keep your glucose levels regulated  so that you do not die, OK? So let's just get that out of the  equation altogether. But I've learned some interesting things by wearing a continuous glucose  monitor.

<p class="pro-tip">Learn about<a href="/blog/what-is-a-continuous-glucose-monitor"> how CGMs work</a></p>

Surprising reasons why blood glucose can be elevated

Now some of these things that drive my glucose up are a little bit more casual than things you probably know of. For example consuming carbohydrates, consuming glucose, is obviously going to drive my glucose levels up2

But I've also learned that certain proteins are going to drive my glucose levels up. I've learned that certain kinds of exercise are going to drive my glucose levels up. And a lot of that comes from the liberation of glycogen — stored carbohydrates in your muscles that are ultimately stored in your liver as well — that are going to get liberated into the bloodstream and give you energy for a given workout. That can drive your blood glucose level up. 

But more importantly I started learning things like poor sleep and stress would elevate my blood glucose levels. Not just in an acute short-term phase, but in a longer-term phase as well. I'll give you a casual example.

How my blood glucose dropped with no change in diet

Prior to Thanksgiving I plugged in my continuous glucose monitor with my Signos app (which we'll talk about a little bit more later on) and I found that my glucose levels were relatively stable but pretty high. Now, mind you, I have a three year old and an eight month old, so I don't exactly get a ton of sleep every single night. Well, during that period I wasn't sleeping much, and my glucose levels were pretty high. Then we go into Thanksgiving time. I'm away from work, I have family members to kind of help take care of the kids for a little bit, and what do you know: my glucose levels drop about 15 points and remain stable there with nothing else changing.

My diet was pretty clean. Yes, we had a spike with Thanksgiving, but overall the diet remained  consistent, and my response to foods changed. So the point here is that stress and sleep deprivation play huge roles. Because you're going to have different external factors: different hormonal factors, and different what are called catecholamines like adrenaline, noradrenaline, epinephrine, and all of that3

Blood glucose can drop for many reasons

But now let's drop over to things that might make blood glucose drop, because that's a whole different ballgame, right? Certain kinds of food can actually make your blood glucose drop because they can trigger an insulin spike that's actually going to bring your blood glucose down. 

But other things, more intense exercise, for example — you're burning up the glucose that you are consuming and your body's actually utilizing it — so that can trigger a drop. And the opposite side of the equation, getting your sleep in or reducing stress can be dropping that blood glucose level. And at the end of this we start saying: okay why does all this matter? What good is it really teaching me?

Blood glucose & body fat

Well I'm going to get into the nitty-gritty of it, but what's really important to remember is one really cardinal thing: if you are having a high spike of your blood glucose related to something you’ve eaten, there is a very high chance that that will get converted into fat4. And I know that this resonated with you because just like anybody, body composition is something that's important. As someone that's lost 100 pounds I completely understand, and I'm very aware when something could potentially cause me to gain fat. 

<p class="pro-tip">Learn about<a href="/blog/mitigate-high-glucose-spikes"> mitigating glucose spikes to avoid fat storage</a></p>

So the goal is to maintain relatively stable blood glucose levels. That's a really difficult thing to do casually, right? You can take people's word for it, you can say that the internet says a certain food is going to modulate your blood sugar, et cetera et cetera. But without your own data it's really hard to tell. And the big piece of the equation comes into the bio-individuality: how different people respond to different foods.

Bio-individuality & weight management

There are some pretty massive meta-analyses that show people respond differently to different foods5. Quite literally, someone can eat cookies and not have the same negative blood sugar response as someone else gets eating a sweet potato. It can be completely wild and completely random. It all depends on you as a person, your genotype, and a bunch of different factors. But if we can acquire the data to discover that, then it paints a bigger picture. So recently I've been wearing a continuous glucose monitor utilizing what is called the Signos app.

Two examples of eye-opening CGM data 

This whole process is really cool because it's allowed me to not only see how I respond to given foods and things like that, but it aggregates that data for me so that I can actually manage my life a little bit better and see this stuff. So I wouldn't know, for example, that oatmeal is causing a glucose spike for me when I'm stressed out, but it doesn't cause a spike when I'm completely relaxed. I wouldn't know that information if I couldn't acquire that data. 

So that's exactly where Signos comes in. Wearing a continuous glucose monitor is great, but if you're not aggregating the data from that glucose monitor into something that's applicable, it's really, really difficult to get a grasp of what you need to change or how you respond to a given food.

<p class="pro-tip">Learn about<a href="/blog/signos-metabolic-experiments"> using Signos for your own metabolic experiments</a></p>

So if we come back to that monk fruit example: I was fasting that day, so my blood glucose should have been pretty stable, and it was. And then I had a little bit of monk fruit with some iced tea, and I noticed that I got a sudden drop in my glucose levels. Well, what the heck? What gives? I even texted the founder of Signos and said, what's what's going on? He said that's really wild, and we started brainstorming and realized that means that there could have been an insulin spike. 

I could get into the deep biochemistry, but I'll touch on it for just a second. Basically, I had an insulin spike that dropped my blood sugar because suddenly my cells accepted the glucose6. Well there's other days where monk fruit has not done that to me, so what kind of factors could be at play here? Again, if you're aggregating the data, you can see that. And who really has time to write all that stuff down and to compile it? If you have it condensed in a simple form it allows you to look at the big picture. 

Why stable blood sugar is the goal

Why is stability so important though? Because we hear people say that you always want to keep your blood sugar stable. And I feel like it goes in one ear and out the other because it's just something we’ve been told constantly. Having stable blood sugar levels is important because that is how you determine when you are going out of range and might potentially gain fat, or when you're going out of range the other way and might have other issues.

A simple example is if your blood glucose levels are stable, even if they're moderately high-ish, as long as you're stable, it's a good indicator that your body is correcting and managing properly. And I think that's the operative word here: it's proper management. We want our bodies to be able to notice that there's a spike in glucose and be able to correct accordingly, with the proper hormonal response to that — which in this case would be insulin and subsequently glucagon. 

If our body doesn't respond to that (i.e. insulin resistance) then the glucose continues to climb and plateaus at a high level. And then we have a problem, because we're unstable. So you could take apples to oranges and compare completely different stable blood glucose levels. But as long as they're stable and not having big rises and falls it's not the end of the world. That's exactly why when you're pricking your finger it doesn't necessarily give you the best readout. Because a finger stick blood glucose reading is a snapshot in time that could have a lot of different variables7

<p class="pro-tip">Read more:<a href="/blog/cgm-accuracy"> Are CGMs Accurate?</a></p>

When so-called healthy foods trigger a negative response

I'm going to circle back to the sort of foods that we might consider healthy for a second. I'm going to give a hypothetical example: let's say I ate a sweet potato, and that sweet potato didn't give me a very serious blood glucose response. I didn't see a big spike in it, so I deemed sweet potatoes as a relatively safe food for me. 

Then mentally in my memory banks I kind of plug it in there like: okay, this is great. This is perfectly good food. Then I go through an extremely stressful period of time. I get really stressed out, maybe I've got a bunch of stuff going on at work, or family, whatever. Well, mentally I have it saved in my mind that I can default to sweet potatoes because they're a healthy food and they don't affect me negatively. Great, right? Wrong.

Because then I have that sweet potato and guess what: because I'm in a completely different physiological state, I have a negative reaction to it. How would I have ever been able to determine that if I wasn't monitoring my glucose continually, and actually having a big picture painted of it, and have it sort of algorithmically laid out for me? 

Discover your invisible blocks to weight loss

Again, that's where Signos comes in: being able to actually look at the data. As someone that's a busy dad, as someone that is a busy person and managing multiple companies, I understand the value of being able to have a snapshot and not have to write everything down consistently. So imagine how this looks with what you've been told for the last 10, 15, 20, 30, 40 years. 

You’ve been told that this is the way to do things. Even with my videos, right? You apply everything that I instruct, everything that I teach, and yet the needle doesn't move, right? And it's easy to pick on yourself: I am the problem. This isn't working. Why isn't this working? What am I doing wrong? And you're beating yourself up. 

Well, until you have the data to truly show how you're responding to something, or what's actually happening, you're going to continue to beat yourself up. It's not your fault, because there are variables that you simply cannot know without being a psychic or having the data. So if you can compile that data, and you can paint a big picture, you can get one step closer to really achieving your results.

<p class="pro-tip">Learn about<a href="/blog/cgms-for-weight-loss"> the scientific evidence for using CGMs for weight loss</a></p>

Science-backed efforts get you further, faster

Remember this mantra: pursue results and reinforce with science. That applies to your data, too. You pursue results, try something new, reinforce it with data to see what is truly working, and then you work forward from there.

How to Get a CGM

Signos is an AI-powered app that pairs with a continuous glucose monitor to give you real-time health data. Learn how you can get the benefits of AI-powered weight loss based on your unique metabolic responses to food, stress, sleep and other factors.

<p class="pro-tip">Learn more about <a href="/how-it-works">Signos plans & pricing</a></p>

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Topics discussed in this article:


  1. MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020 Jun 24]. Blood Sugar, Also called: Blood glucose. [updated 2017 Jun 15;]. Retrieved May 18, 2022, from:
  2. Good to Know: Factors Affecting Blood Glucose. (2018). Clinical diabetes : a publication of the American Diabetes Association, 36(2), 202.
  3. Paravati, S., Rosani, A., & Warrington, S.J. (Updated Oct 30, 2021). Physiology, Catecholamines.  In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Creative Commons Attribution 4.0 International License. Retrieved May 18, 2022 from:
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  6. American Diabetes Association. (n.d.) Insulin Basics. Retrieved May 18, 2022, from:
  7. Olansky, L., & Kennedy, L. (2010). Finger-stick glucose monitoring: issues of accuracy and specificity. Diabetes care, 33(4), 948–949.

About the author

Thomas DeLauer is an expert in diet, nutrition, and mindset. He is motivated by a guiding ethos of integrated optimization: if you perform better, so does the world.

View Author Bio

Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

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