The first time I tracked my blood sugar, I wrote about how it humbled me and knocked my wellness socks clean off, before eventually bringing me around to the idea that glucose monitoring -- tracking the ebbs and flows of blood sugar throughout the day and over time -- can be very telling of overall health in ways you may not realize.

For the past few weeks, and with a break or two between sensors, I've been wearing the Lingo continuous glucose monitor, also known as a CGM, made by Abbott, one of two diabetes care "big wigs." (The other diabetes tech giant is Dexcom, whose Stelo CGM I wore for my first time tracking blood sugar.) Like Stelo was for Dexcom, Lingo is the result of Abbott turning a medical device that once required a prescription into consumer tech cleared by the Food and Drug Administration for use by any adult who doesn't need insulin and wants a deeper dive into how their diet and lifestyle affects blood sugar. This is important, as glucose levels can tell you about your diabetes risk and overall metabolic health, giving you a leg up and some agency to make changes or get care as you see fit.

Lingo is a small, circular biowearable that sticks to the back of your arm and tracks your glucose in real time through a teeny sensor that reads glucose levels in interstitial fluid, which leaks out of surrounds cells and gives away their blood sugar contents. While there have been workarounds for people without diabetes to get a prescription for CGMs through biohacking companies like Nutrisense and Levels, having blood sugar biosensors cleared directly for the general wellness market by the FDA is a big deal, since glucose remains a crucial health marker that smartwatches, smart rings and any other regular consumer wearable can't touch yet. Apple is getting closer to adding glucose tracking to its smartwatches, reports from Bloomberg suggest, but it won't be our reality in the near future, as the only tech that can reliably track blood sugar so far needs to (literally) get under our skin.

So, how does the Lingo -- marketed specifically for general wellness consumers -- compare to the Stelo, whose target customer base is those with Type 2 diabetes or those in the prediabetes zone? Here's what I found, what I like about the Lingo app and where I think it can improve. Also, we'll take this moment to debrief what current scientific evidence says about glucose as a measure of our metabolic health -- the very function of our bodies and how they use energy.

Why you should care about blood sugar or glucose

When we eat, our body converts food (mostly glucose or "sugar") into energy, which our body breaks down, uses and stores. So naturally, we get a little uptick or energy boost after a meal -- especially from carbohydrates, which are made up of simple sugars -- and our body releases the hormone insulin in response to help convert energy and bring blood sugar down. 

People with diabetes have a disrupted insulin response, and people with Type 1 diabetes, as well as some with Type 2 diabetes, need to take insulin as medication. 

However, in people without a diabetes diagnosis, blood sugar that stays too high for too long can also pose health problems or indicate an underlying problem, such as illness or even prolonged stress or sleep disturbances. It can also mean insulin resistance, where the body has to work harder to produce enough insulin to clear blood sugar from the blood, which can lead to prediabetes and Type 2 diabetes if not managed. 

Diabetes or too-high blood sugar becomes a problem because blood sugar can damage nerves, hurt kidneys and more. Fortunately, prevention or management of diabetes is possible, which is where CGMs come in. 

Dr. Scott Isaacs, a board-certified endocrinologist and president-elect of the American Association of Clinical Endocrinology, told me last summer during my first stint monitoring my blood sugar that CGMs have a leg up against traditional blood sugar tests, such as the A1C test you may get as part of typical blood work, because they give you a days-long range of information. 

You can also get actionable insights into how different habits or choices impact glucose. For example, I've found that walking around after a meal not only makes me feel better but reduces the severity of my glucose spike after eating. I've also tried to eat a little more protein (nothing too dramatic), as research has shown that starting with protein or less sugary foods also helps stabilize blood sugar. 

All of this health insight, and more, is available on the Lingo app, so you can learn as you watch your glucose levels naturally rise and fall throughout the day.

Read more: TikTok Spotted My Diabetes Before I Did. 2 Gadgets I Now Use Daily 

Getting started with Lingo 

Abbott originally announced Lingo at CES 2022 as part of a line of biosensors that will, one day, the company says, be able to track not only glucose but other metrics like ketones (bodily acids that break down fat for energy) as well. With all this build-up, I've been itching to try the Lingo. A single biosensor, which will give you two weeks of data, costs $49. A whole month (two sensors) costs $89, and if you're really in it for the long haul, you can opt for a three-month subscription of $249.

Unfortunately for Android users, Lingo only works with iPhone currently. If you're an Android user and want to track your blood sugar or glucose, you should get the Stelo by Dexcom, which works for both Android and iPhone.

Because I'd already worn a CGM for about a month earlier this year, I had an idea of what to expect this time around. In my experience, setting up Lingo was virtually painless, less loud than the noise Stelo makes when being injected into my arm and easy to do. 

The first step is to download the Lingo app and create an account. Then, sterilize the back of your arm where you'll be attaching the biosensor -- Abbott recommends you use soap and water first, then an alcohol wipe. 

Lingo comes in a box with two components: a gray biosensor applicator and a white biosensor pack that comes with a peel-off lid. To prepare your biosensor for your arm, peel off the biosensor pack lid. Then, unscrew the applicator cap and line it up with the biosensor pack per the instructions. Push it firmly down so the biosensor attaches to the applicator. Once your biosensor is loaded, follow the applicator instructions and push firmly on the sterilized part of your back arm. Then, scan the biosensor with your phone so it pairs. It takes about an hour to warm up and officially start measuring your glucose or blood sugar. 

Pros and cons of Lingo app 

I appreciated the relative transparency of the Lingo app and what are good glucose goals to aim for. On the "today" screen, which shows a graph of real-time glucose information, you'll see dotted lines outlining the "healthy range." This range -- between 70 and 140 mg/dL -- serves as a parameter for people who haven't been diagnosed with diabetes to stay between. Many reports say that 96% of the time, you should aim to keep it below 140 mg/dL. 

I also liked how Lingo/Abbott has a "common questions" section under the "challenges" tab, which gets into what the target range means and what it indicates if you "see spikes." The app explains how spikes are normal after eating but should return to baseline about 90 minutes later. While there's very little official health word on what your graphs or numbers should look like as someone without diabetes, this guidance seems to run with how the Centers for Disease Control and Prevention uses 140 mg/dL as a cut-off for a prediabetes diagnosis during the fasting glucose test -- that is, two hours after consuming glucose, your body should bring your blood sugar down below 140. I appreciated the extra health context Lingo provides. 

Now for something I want to like but can't get behind yet: the Lingo Count. I don't get it. It's a number that supposedly represents your glucose spikes throughout the day. Everyone's "target" starts at 60, but you can adjust it higher or lower based on your own goals. You'll see it go up throughout the day, and you can look at how your counts stack up as the week goes on. The goal is to stay under your target count. 

Pamela Nisevich Bede, a registered dietician, nutritionist and senior manager of medical affairs at Abbott, said that the Lingo count is meant to provide more context for people who haven't had any experience tracking their glucose before and may want an easier score to go after. But Bede said it's something they're always looking at, as blood sugar tracking in people without diabetes is still a new concept. 

"It's a value that we're always playing with," Bede said about Lingo Count. "We're always looking for new research into individuals without diabetes -- what's that going to look like in five years? I think, 'more to come'." 

While it does feel similar to a wearable readiness score, I prefer just looking at the graph and seeing how my glucose goes up and down throughout the day. I should also say, while I love my Oura data, I only look at the actual data (sleeping time, temperature trends, etc), and barely give the numerical Readiness Score a glance. So maybe someone who finds the more holistic wearable scores or briefings useful will appreciate Lingo Count. 

However, the Lingo app does give you a list of Lingo Counts throughout the day that prompt you to log an event (food, most likely), and I find this helpful to make note of the "big" glucose events so that you don't have to sweat the small snacks or activities. As I wrote for my first CGM review, I'm not a fan of food logging, even when it's not asking for calories, because I think it sets a potentially harmful precedent and you can get yourself into the swing of checking the app/your glucose graph periodically throughout the day to see how it may affect you. 

Another thing I didn't love about the Lingo app is the attempted motivational wording it uses in the "Today" tab. It's possible I'm reaching and not everyone will feel this way, but praising phrases like "Good job today" when the app is centered around eating and diet feels weird and makes my spidey senses for disordered eating potential tingle. 

I also laughed out loud when I looked at my glucose measurements after my first coffee of the day recently (I added oat milk and sugar) and the app suggested I get up and do 20 squats because my Lingo Count was going up. Other things I didn't appreciate: When the Lingo app told me to do calf raises and put some "tunes" on while I cleaned up after dinner. 

Glucose tracking 2.0: Lingo vs. Stelo CGM

I was more prepared, and less scared, during my testing of Lingo than I was when I first attached Stelo. During the latter's testing, I was flying blind in terms of what "normal" glucose fluctuations were supposed to look like. I also experienced (what seemed to be) markedly different glucose levels from the start of my Stelo run to the end. I have had no formal diagnosis or medical conclusion drawn around any of this. Still, my hypothesis for why this happened is that I was sick and recovering from a virus when I first started using Stelo, combined with generally high stress. Comparatively, my Lingo glucose levels have been lower, though that may be credit to both companies' apps and biosensors doing their job of teaching me subtle ways to help regulate blood sugar, such as taking more walks and being mindful about eating protein or fattier, more satiating foods before the high-carb or sugary stuff. 

App-wise, in addition to Abbott more clearly defining what's "okay" vs. what should prompt you to reach out to your doctor for more information or guidance, I liked the graph set up more on the Lingo app, since you can toggle along the dotted line and go back days to see how your glucose has risen and fell. However, I personally find the motivational language a bit ridiculous (while well-meaning), so I think the copy could be improved in future versions of the app to be more hands-off and less micro-managy. In this sense, I think Stelo is superior. 

Importantly, whether you should go with Stelo or Lingo hinges mostly on whether you've been diagnosed with Type 2 diabetes (but aren't taking insulin) or if you think you're prediabetic. If either apply, you'll probably want to try the Stelo CGM, as it offers a higher target range up to 180 mg/dL and is generally less competitive/annoying with challenges and prompts. 

Of course, a big con to Lingo is that it is (currently) only available on iPhone, so it makes for an easier choice for Android users. 

Read more: Apple Watch Now Pairs Directly With Dexcom G7 in Diabetes Tech First 

My blood sugar had more "lows" with Lingo, so I investigated a crash 

For my first documentation of blood-sugar tracking with the Stelo CGM, I spent most of my time obsessing over highs and getting to the bottom of spikes. But my glucose levels have been lower with Lingo, so I want to spend time on a different, related phenomenon: the blood sugar crash. 

Something about 3:30 PM on a weekday makes me feel extremely unwell. On one occasion, I felt so tired and headachey, post-lunch, that I decided to check in with Lingo and see what my nifty glucose sensor had to say and if there was any correlation. 

Indeed, while I was feeling particularly "blah," my blood sugar had dipped below the bottom range of 70 mg/dL -- surprisingly low for me. In a person with diabetes or someone who takes insulin, this may be concerning and prompt some type of action. However, I don't have diabetes, so this was less a medical concern and more a head-scratching event to pick apart. What's more, I'm wearing the Lingo, which is a consumer wearable device -- not one approved for medical purposes.

All that being said, here are some of my guesses at the culprits of my crash: 

I was drinking a Diet Dr. Pepper right before The Crash. I usually only drink soda (artificially sweetened) when I go into the office because the bright fluorescent lights overhead tire me out and give me a headache (yes, I'm a wimp), and I've usually burned through my coffee quota earlier in the day. Could artificial sugar be the problem? I haven't found any evidence to suggest it would.

I was munching on bread -- more of it than I normally have when not paired with other food. Bread is delicious and absolutely part of a well-rounded diet, but it's very carby. Before the naan bread and Diet Coke, I had a banana, half a can of lentil soup and a bite of a red bean rice cake. While I wouldn't call this an unhealthy meal, it was pretty carb-heavy and not padded by a dose of protein up front, so I may've been doomed to crash. 

Tiredness. The two nights before, I'd had pretty poor sleep. About five and a half hours the previous night and about six and a half the night before that, according to my Oura ring data. Could I once again be victim to my own poor sleep choices? Probably. 

Taking all of this into account, the things I can do differently next time to avoid this crash lean on the same general advice when it comes to helping your body process blood sugar and, therefore, energy after eating. I could've taken a quick, leisurely walk after lunch (nothing crazy, and no sweating) and considered eating protein before the more carby foods. Maybe I could've added a slice of cheese to the soup or eaten the banana after.

Who should use Lingo or try a CGM? 

I regret to inform you that, after spending weeks with two different models of CGMs, I think it's a good idea for everyone to use one to track their glucose levels at least one time -- preferably once a year for as long as your box of biosensors will serve you, just to check in with how your body's handling blood sugar and to play around with your wellness routine. And this is coming from someone who is adamantly against calorie counting or similar types of food logging for most people. To reiterate: I disagree with the current app designs around consumer CGMs and don't think you need to log every single food item to learn how different foods impact blood glucose.

People who have diabetes or prediabetes (and who don't need insulin) may benefit from wearing one more often (you should get the Stelo, or ask your doctor whether you can get a prescription for another one). However, whether you need to "continuously" use a continuous glucose monitor is totally up to your preferences and what benefits your overall well-being. That includes how stressed it makes you feel and whether you think it's actually helping you make meaningful changes to your routine. If it's not helpful, forget it.

For those who think they may have prediabetes or people who are worried about what their graphs may show: I feel you. Whether you want to wear a CGM or check your blood sugar ever is completely up to you, but given that the resources available for people to catch potentially chronic diseases early are sparse -- and the noise around diet trends or wellness hacks purporting to make you healthier is loud and confusing -- you may find that a tool that gives you direct information about your health can help you make tweaks that'll actually be helpful. It may also prompt you to get care earlier if you can benefit from health care or medication, minimizing the risks of health problems later on in life.

I offer the yearly glucose check-in advice for most people because that's what I plan on doing, and based on some Reddit threads and general comments from doctors, using a CGM to check in every once in a while seems to be more in line with how others view it as well. While I was provided CGMs from both Abbott and Dexcom for testing, I'll probably buy a single Lingo biosensor roughly a year from now, just to see how my blood sugar is trending, purely based on the fact Abbott sells a two-week sensor for a more affordable $49, instead of a month-long sensor pack for $99. In the meantime, I plan on overhauling my sleep routine and working on bringing down my stress levels, so I'm focusing on those gradual changes that can reap big, rippling health results.