I never thought I’d find myself racing home to pick up a package and punch its contents my skin. But there I was, tearing open the sleek black box from Levels and eagerly pulling up Youtube videos on how to staple this device into my arm.

Said device, a continuous blood glucose monitor (or CGM), was something I’d been waiting to try for almost a year. I am by no means diabetic, but there is a history of abnormally high blood sugar levels in my family. After a relatively high A1c reading in college, my interest in blood glucose was piqued.

I’d discovered Levels, a health tech company trying to consumerize metabolic health maintenance through CGMs, sometime in 2020. I’d been sitting on their public beta waitlist ever since. Once I was finally admitted, it is not an exaggeration to say that everything I thought I knew about nutrition and health was turned upside down. This is my personal review of Levels Health.

What is Levels Health?

Levels is a relatively new company, founded in 2019, on a mission to improve the world’s metabolic health. They hold that the US is experiencing a “metabolic health crisis,” based on a few key metrics:

Over 10% of Americans have diabetes
1/3 have prediabetes (and more than 84% don’t realize it)
¾ of Americans are overweight or obese, which is a major risk factor for diabetes

Levels produces a proprietary app that provides a real-time data stream from a CGM. The app adds a layers of visualization and gamification to your day, registering your blood sugar levels on both a line and circle graph, as shown below. Green indicates stable blood sugar, red indicates spikes-to-be-avoided. The app integrates behaviors like sleep and exercise from popular wearables, like Apple Watch, but all meals must be logged manually. Each inflection point for your blood sugar is indicated by a white icon on the line graph.

The main interface of the Levels Health app

Levels has produced a ton of content on what they believe to be acceptable blood glucose levels for various circumstances, like when you wake up in a fasted state or when you’ve just had a meal. Importantly, their guidance is much more conservative than the CDC’s.

What is continuous glucose monitoring?

CGMs are small, wearable devices that track glucose levels in the interstitial fluid just beneath your skin (why they must be “stapled” in). Traditionally used by people with diabetes to manage their blood sugar levels, CGMs provide a continuous stream of data about how much sugar is in your bloodstream at any one moment, giving you better insight into how different foods, exercises, stressors, and sleep patterns affect your blood sugar levels.

The continuous nature of glucose monitoring is relatively new; the first ones weren’t available until 1999, so the technology is only about 20 years old. Its introduction marked a huge leap forward in the glucose management world. Rather than diabetics having to prick their skin multiple times a day to understand their sugar levels, CGMs can send a constant stream of data to a phone or computer, even sending alerts when there’s a concerning drop or spike.

Despite the relatively new technology and notably little evidence that CGMs can help manage anything outside of diabetes, CGMs have gained traction among health enthusiasts, biohackers, and wellness seekers who are eager to optimize their health. Sound familiar?

Why use a CGM if you aren’t diabetic?

One reason, mentioned above, is that you may have no idea that you’re on the road to diabetes. Using a CGM to measure your fasting, pre-meal, and post-meal blood sugar can help detect whether you’re at risk for developing metabolic syndrome. One benefit of this deep dive is my now expert-level awareness of the perils of diabetes: among them are heart disease, kidney disease, vision loss, and foot/hand amputation. It is - seriously - not uncommon to go blind or lose a foot from diabetes.

Another reason to track is that fluctuations in blood sugar can affect energy levels, mental clarity, and mood. Blood sugar crashes are real and visceral, the result of an influx of sugar to the blood that your insulin system quickly mobilizes around and brings crashing down. This one is a bit more in line with the Blue Sky Mind mission. When I experience one of these crashes, I feel a deep sense of fatigue, clamminess, and crankiness. Notably, not very positive at all.

Personally, I wanted to learn what I could about my own body’s relationship to blood sugar. Read on for insights gained from my one-month experiment.

How I approached my Levels test

Due to the high price tag of this new technology, I decided to try it for just one month. I paid $400 upfront ($200 for the hardware, $200 for the app subscription), but was able to cancel the subscription after and get a $200 refund. In my opinion, $200 to get a month’s worth of unique, personalized biodata was worth it.

However, a month isn't a long time if you’re not being intentional about data collection and testing. I conduct a lot of research at work, so I decided to treat my one month of Levels as a mini research study, with goals, hypotheses, key metrics, and a readout on the learnings.

Test details

Timeframe: Friday, Feb. 24 - Friday, Mar. 24
Goal: Validate whether my “healthy” eating efforts are actually keeping my blood glucose stable & understand how bad my various indulgences are for my blood glucose
Metrics:

Primary: Glucose stability / levels score (higher = better)

My research questions & hypotheses:

Question: Do my most common “healthy” meals actually keep my blood glucose stable?

Hypothesis: Yes, for the most part, as long as I pair protein, fat, and carbs.

Question: How badly do my most common indulgences affect my blood glucose?

Hypothesis: Some are worse than others; baked goods will be the worst, ice cream in the middle, and alcohol relatively low

What does “glucose stability” mean to Levels?

As soon as Levels detects a steady rise in your glucose levels, usually post-meal, it starts to track whether or not it rises over 30 mg/dl. If it goes over this amount in a short time frame, you get a notification that your blood sugar is “spiking.” The higher and longer the spike, the lower of a score Levels gives you on that particular meal. As part of this experiment, I was seeking high scores on my meals.

Did you test any common hacks for managing blood sugar?

During this test, I ended up picking up Tim Ferriss’s book “The Four Hour Body,” which contained a number of hacks for stable blood sugar. I decided to incorporate a few into my test.

This is where Levels recommends you apply your CGM while using their product.

My Levels test results

Overall, I was edging up against most of Levels’ conservative benchmarks for metabolic health. I was spiking 2x more often than recommended, leading to much more overall spike time than Levels would want to see. Despite that, my average glucose came in right under their recommended threshold…but by just 1 mg/dl. Factoring in some margin of error, and I think, at best, Levels would call me moderately on target, if not a bit concerning. Yikes.

Levels Health’s guidance on optimal metabolic health ranges

Lessons learned from my Levels test

Surprisingly, the majority of my “healthy” lunches & dinners cause high blood sugar spikes. Quinoa or rice bowls, takeout salads, Amy’s frozen meals, chickpea pasta, legume-based soups, and Thai or Indian food with rice cause significant spikes to my blood sugar. It did not matter that I always paired the carbs in these meals with fats and proteins. I learned that, almost without fail, if I eat quinoa, rice, sugary dressings, fruit, and/or refined legumes, I’m likely to have a high spike.

The majority of my “healthy” breakfasts & snacks are good for glucose. Choosing either eggs, bacon and beans or a smoothie for breakfast keeps my blood sugar very stable. Having fruit, like oranges or pears, with my eggs does not. Oatmeal sends my blood sugar soaring and avocado toast is borderline. Snacks like fruit with nut butter and popcorn cause a moderate response, but cottage cheese and low-carb protein bars cause almost none.
As expected, the majority of my indulgent meals lead to high blood sugar spikes. The only exception is dry wine and cheese/charcuterie, which produce very stable responses in me. Dumplings, baked goods, pasta, and sandwiches all lead to meaningful spikes. Ice cream produces a moderate effect, likely due to the balance of fat and sugar.
I could meaningfully mitigate my blood sugar spikes in a few ways. I found that, 20-30 minutes before a high-carb meal, if I did a strenuous workout, had a high-fat snack like charcuterie or a tbsp of apple cider vinegar or lemon in water, I could sometimes reduce a blood sugar spike from high-carb meals. The most reliable way to reduce a spike was through strenuous exercise or high fat consumption. The least was using acids, though I didn’t rigorously test using two vs. one tbsp pre-meal.
I’m likely more “gluco-sensitive” than the average person. I was disappointed to find out that foods like oatmeal, quinoa, oranges, sweet potatoes, chickpea pasta and certain soups and salads had a significant effect on my blood sugar (and not in a good way). These foods would regularly produce not just a 30 mg/dl spike (Levels’ threshold for “high”), but >60 mg/dl. Despite their high nutrient content, they could produce the same glucose response as a croissant, slice of cake, or bowl of pasta.

How I felt about the learnings

If I’m being honest, I spiraled a little after my one-month Levels test. I was so confused and bummed to learn that things like oranges, oatmeal, and sweet potatoes - foods I’d been led to believe my whole life were near-perfect nutritional specimens - were dramatically spiking my blood sugar in ways Levels said was unhealthy. It’s tough to know what to make of this, because Levels argues for much lower “safe” ranges than the CDC.

Over the course of 2023, I discussed my results with two primary care doctors (PCPs) and three registered dietitians (RDs), trying to arrive at the “so what?” I tried consulting my doctor about it (Dr. Tom and I, we go down rabbit holes like this), but rather than solving the complexity, he added to it by having me read books on opposing viewpoints in the medical literature on the topics of diet and longevity (peep “How Not to Diet” by Michael Gregor, if interested).

The second PCP sent me to an RD, who said I was doing all of the right things and that I must have a system relatively sensitive to glucose. Another RD asked if I ever feel crappy after these so-called “spikes” in my glucose, and truth be told, I don't. Not from sweet potatoes or quinoa. She advised me to listen to my body over the CGM. The final RD cautioned me against cutting out nutritious foods like oranges and oatmeal, just because they produced a spike. She worried aloud that companies like Levels have started to demonize nutrient-dense and generally-advisable healthy foods, like whole grains, fruits, and legumes.

Notably, not one doctor advised that I cut out the nutritious foods that were causing me to “spike.” There was a general consensus here that the CGM data is so new, and the best science we have tells us that the benefit of eating oranges and sweet potatoes outweighs the risk they pose to gluco-sensitive individuals.

Levels Health review: pros & cons

Phew. Ok, getting back to the tech itself. Below are my top pro’s and con’s for Levels Health:

Pros

Data. I, like most modern humans, am a sucker for personalized data. I do appreciate knowing what foods and/or behaviors I’m more sensitive to.
Education. Levels helped me become much more aware and informed about metabolic health as a key pillar of longevity.

Cons

Application. I hated punching that CGM into my skin; if you get it wrong, you can be in a lot of discomfort and even bleed through your clothes.
Interpretation. It’s definitely a little dangerous to try to interpret Levels data by yourself. I had to speak with five health care professionals before feeling confident in my interpretation.
Stress. Continuous monitoring can make you obsessive about checking your data and what you’re eating. An article by Fast Co dubbed it the “pathological stress of glucose readings.”

That one time I put the sensor on slightly wrong & bled through my white shirt.

Why did I cancel after one month?

Despite getting some fascinating results from my Levels test, the experience doesn't quite justify the recurring $200/month hardware cost. Here’s why:

Invasive monitor: I’m looking forward to the day when this is a topical skin monitor vs. something you have to punch into your skin, as I had one very poor insertion experience. Eagerly waiting for Apple to come out with their non-invasive CGM!
Expensive: Obviously, it’s extremely costly. I might try this 1x/year for the cost until prices and invasiveness come down.
Limited/beta UX: The user experience still feels pretty beta (which was fine, because in this case, I was an early adopter).
Weak analytics: I feel that the Levels analytics are a bit hard to parse and draw strong conclusions from. For example, I strongly believe that after entering a few meals, the app should start to draw correlations and inferences about which foods help or hurt your blood sugar.
Lack of integrations: I also believe there should be integrations with popular food logging apps like Noom or MyFitnessPal, so that people who track their food intake don’t have to do it more than 1x/meal.

In conclusion

I’ve studied health and wellness since I was in high school, always seeking some sort of understanding that will allow me to finally master my body and mind. I came to this product for the same reason, but left feeling more confused than confident about nutrition.

Truth be told, I’ve never looked at food the same since trying Levels. I’m constantly conscious of what high-carb or sugary foods are doing to my body. It makes me think twice about every cookie, cracker, dinner roll and piece of candy. But I’m not sure it’s actually resulted in behavior change…just more hand-wringing. It’s not yet clear to me how much I need to be worrying about these blood sugar spikes, and therefore, I’m not motivated enough to avoid them completely. And yet, I have a nagging feeling that Levels is the one on the cutting edge of health science, and my doctors are not. I fret more about what I’m eating than ever.

If you’re someone who has metabolic syndrome or diabetes in the family, a one-month test can arm you with a lot more awareness on the topic. But for someone without diabetes or prediabetes, the benefits of Levels do not yet outweigh the costs (for me).

If you like content like this, subscribe to Blue Sky Mind’s email newsletter. Or, if you’d like to build a more personal relationship, follow Blue Sky Mind on Instagram.

Up Next: