The Cambrian explosion of CGM-based personalized nutrition programs

You CGM, right, bro? How CGMs are becoming the next Fitbit — and how they change the metabolic fitness game.

Hi friends 👋

Welcome to Health & Wealth — your weekly source of the latest health research and biotech trends. Here's the full piece on CGM-based nutrition startups, as promised! Gentle reminder that I'm not a doctor — this is not medical advice. Just sharing what I learn.

As the holiday season approaches, know my publishing schedule may be a bit off, but I intend to keep writing. DM or reply if you want to see any specific biotech company analyses from me. If you are new, you can join here and share within your network — word-of-mouth is how I grow. Happy reading!

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Article Highlights

• Continuous glucose monitors, unlike traditional blood tests like HbA1c, tell you what your glucose levels are in real-time. This is useful because glucose levels fluctuate throughout the day depending on your diet and lifestyle choices.

• 1 in 3 American adults has prediabetes. Of those with prediabetes, more than 84% don't even know they have it. But even if you don't have diabetes, higher glucose variability negatively impacts health.

• There's a recent Cambrian explosion of startups trying to bring CGMs to the masses — to help athletes improve their fitness, laypeople to avoid afternoon energy slumps, and unaware pre-diabetics to prevent diabetes.

• Levels Health, NutriSense, January AI, ZOE, and Tastermonial are a few examples of players in the CGM-based personalized nutrition space.

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For some, nutrition is as sensitive as politics — people have strong opinions about what to eat. But the question I've always genuinely wondered is: how do you really know what foods are healthy for you?

Most of us have a hunch about what's "healthy" or not — educated guesses based on conventional nutrition advice, maybe a sprinkle of headline-based scientific research, and what our moms told us growing up.

xkcd

But what if that greek yogurt and fruit breakfast combo you think is "healthy" is actually spiking your blood sugar higher than processed white bread? Or what if your "guilty pleasure" foods aren't doing as much metabolic damage to you as you thought?

Enter: continuous glucose monitors (CGMs).

CGMs are sensors that tell you your glucose levels in real-time. This is useful because glucose levels fluctuate a lot during the day depending on what you eat, when you exercise, how well you sleep, etc.

Your blood glucose levels are far from static — it fluctuates a lot, hour by hour.

Historically, CGMs require a doctor's prescription and have been reserved for people with diabetes, Type 1 in particular.

But I've noticed something peculiar about CGMs lately. In the past two years alone, there has been a Cambrian explosion of startups trying to bring CGMs to the masses — to help athletes improve their fitness, laypeople to avoid afternoon energy slumps, and unaware pre-diabetics to prevent diabetes.

These startups believe that CGMs should be as ubiquitous as wearing a Fitbit or Apple Watch. Why? Because tracking glucose is key to understanding how our bodies uniquely respond to food and lifestyle choices. The adage — one person's poison is another's medicine — rings true for nutrition. There's no one-size-fits-all.

To understand this growing trend and why CGMs are a huge untapped market that most people don't realize, we'll work our way up:

• How CGMs are different from standard glucose blood tests

• What can I learn by using a CGM?

• A quick tour of a few CGM-based personalized nutrition startups:

  • Levels — the Equinox of CGMs

  • Nutrisense — a data scientist's best friend

  • January AI — if AlphaGo were a nutrition program

  • ZOE — a holistic platform beyond just glucose

  • Tastermonial — A/B testing foods with a CGM

• The big picture

How CGMs are different from standard glucose blood tests

So why would you want a CGM in the first place?

The main reason is to help you maintain consistent blood glucose levels. Quantitatively, this is known as time-in-range (TIR). The name of the game here is to avoid wild swings of blood sugar levels that are too high or too low.

How is this different from standard glucose blood tests?

Blood tests done in doctor's visits — like HbA1c — only show you averages. It's a snapshot in time, not a continuous data stream. Another standard test is fasting glucose — your morning glucose levels after an overnight fast. You might remember having done this before if you've grumpily driven to get your blood drawn on an empty stomach.

While tests like HbA1c and fasting glucose are standard-of-care tests to screen for diabetes, they can't show you the time you've spent out of range. Here are three different blood glucose profiles that all have the same HbA1c value:

Same HbA1c. Three completely different glucose level profiles. Image credit

Measuring HbA1c is like only seeing a stock price's 3-month average. No insight into what price it's at now, what the past trends look like — nothing. The price could be fluctuating wildly or be a static flatline, but you would never know.

With a CGM, you get to get instant feedback on your glucose response.

How current CGMs work

Current CGM models can read glucose levels using a flexible metal filament around 5mm long and 0.4mm wide. This filament pokes into the body fluid around cells (interstitial fluid) just below the skin.

Glucose is found in interstitial fluid because it continuously seeps from your blood vessels and capillaries. It's not the same as what's actually in the bloodstream, but it's a decent proxy.

The sensor filament stays in place for ~2 weeks. A transmitter wirelessly sends the information to a monitor (either a separate reader device or smartphone app).

Image credit

Abbott, Dexcom, and Medtronic are companies leading the way in the CGM market. It's worth noting that these sensors can deviate a bit from one another. Certain systems can report lower (or higher) numbers than others — and that's probably a function of both differing technologies and where on your body the sensor's placed.

For my OG readers, this section may look familiar 😉  I've written about needle-free CGMs before — if you want to check out what the future of CGMs can look like, you can read that piece here.

What can I learn by using a CGM?

You might be wondering, Okay — streaming vs. static data. But how does glucose variability impact my health?

Higher glucose variability (huge spikes and drastic drops) is associated with an increased risk of cardiovascular disease, Alzheimer's disease, cancer mortality, and all-cause mortality compared to lower glucose variability — even in people without diabetes. When there's too much glucose in your bloodstream, it can cause vascular damage, oxidative stress, inflammation, coagulation.

This is all to say — your glucose levels matter, a lot.

Scared of what a CGM will tell you yet? 😂

When using a CGM, there are 3 factors to optimize for:

1. Peak height — Minimize the height of glucose peaks. It's ideal to have no glucose excursions above 140 mg/dL.

2. Glucose variability — This is the "delta value" between your highs and lows. I see different proposed optimal ranges, but sounds like for the standard deviation in glucose readings — below 20 mg/dL is decent, below 15 mg/dL is ideal.

3. Time to baseline — The time taken to lower glucose levels back to average after eating. Usually within 2-3 hours post-meal.

The medical community has yet to reach a consensus about whether it's worthwhile for people without diabetes to use a CGM. But I'm assuming if you're here, you're curious to learn what's at the forefront of health optimization.

So, what specific insights can you learn from using a CGM? That's up for you to decide — what do you want to know about your body? You can design N-of-1 experiments accordingly.

Some questions you could try isolating and answering include:

• Do my go-to "healthy foods" — coffee, yogurt, chicken and rice, etc. — keep my glucose levels steady?

• Vice versa: do my go-to "guilty pleasure foods" — dark chocolate, red wine, ice cream, fries, etc. — spike my glucose hard and quick?

• Do the same foods eaten at different times of the day (morning, mid-day, evening) impact my glucose response differently?

• How much does walking post-meal blunt my glucose spike?

• Does sauna or cold showers impact my blood glucose?

• Does sleep quality impact my glucose levels the following day?

• For ladies: how does my blood glucose change over different phases of my menstrual cycle?

• etc. — choose your own adventure 😄

If you're not already familiar with "biohacking" — this gives you a sense of the biohacker's spirit. You can get really intense about these things real fast.

Greater visibility into nuanced, individualized glucose responses makes it easy to understand why CGMs have become a hot frontier in personalized health. Personally, I find it fascinating to understand how my body responds to my daily life choices.

A quick tour of a few CGM-based personalized nutrition startups

This section is for you if you're interested in trying out a CGM and want to know what your options are.

A while back, I posted a question on r/biohackers about where to get a CGM for people without diabetes. As the CGM trend blooms, so have companies offering CGMs to health optimizers.

These services ship you a CGM (a doctor from their team prescribes you one). Their app helps track and make sense of your CGM data while you use it.

I will keep my introductions to a few of these players short, but you can check out blog reviews that compare and contrast the user experience more in detail here and here. I hesitate to endorse these review pieces fully because they seem to always sneak in an affiliated promo code to one of the mentioned companies.

Okay — here we go:

Levels — the Equinox of CGMs

Levels is as exclusive as Equinox is in fitness. They've developed somewhat of a cult following and have increased exclusivity by putting all new users on a beta waitlist. Like Equinox, high-profile influencers are seen using Levels — often raving about it on social media:

Patrick OShaughnessy @patrick_oshag

.@Levels is one of the most interesting products I’ve used - reveals how nuts it is that we know more about what’s happening in our cars or computers than our bodies - great example of “static to streaming” - only thing that’s ever made me willing to log food (logging > insight)

September 10th 2021

19 Retweets322 Likes

Levels is stellar at marketing and defining the metabolic fitness market. They have a compelling founding story and I've heard anecdotally they raised their $12m seed round largely based on Silicon Valley VCs wearing CGMs, making their fellow VC friends ask about it. Talk about a high net promoter score.

Cost: $398 ($199 for annual membership, $199 for one CGM kit)

What you get:

• One year of Levels Membership

• 28-day supply of CGMs (two 14 day CGM sensors)

• Nutritionist coaching

Nutrisense — a data scientist's best friend

If you love geeking out about and analyzing your own data, NutriSense is your boy/gal. Their app is polished and well-integrated with the FreeStyle Libre CGM. You can also speak with a registered dietitian to get the most out of their program.

I've heard that the app has a lot of information, including food macros, which can be great for some but potentially overwhelming for others. Nick Urban wrote up a review on NutriSense, detailing his experience.

Cost: $350 per month (lower price for a longer time commitment)

What you get:

• 28-day supply of CGMs (two 14 day CGM sensors)

• Access to NutriSense app

• One month of dietitian support

January AI — if AlphaGo were a nutrition program

Can you tell I've been watching the AlphaGo documentary recently? 🙃

If AlphaGo were a personalized nutrition program, January AI would be it. Their "Seasons of Me" metabolic program combines your food logs, physical activity, heart rate variability, CGM and other data sources to produce hyper-personalized recommendations.

Once trained, January AI can accurately predict how different foods and activities will impact your blood glucose — up to 33 hours in the future. This algorithm is based on a 1,000 person study on how people's glucose responses vary.

Machine-Learned prediction of glucose response for 1000 subjects. Image credit

January AI is co-founded by Dr. Michael Snyder — Stanford's Chair of Genetics and Director of the Center of Genomics and Personalized Medicine. I remember being blown away the first time I sat in one of his lectures. His talk about the importance of glucose monitoring has stuck with me ever since (clearly).

I have high hopes and really want to try this one out.

Cost: $288 (early access offer, regularly $488)

What you get:

• 28-day supply of CGMs (two 14 day CGM sensors)

• 90-day guided program with access to January AI app

Note: you will need an existing heart rate monitor.

ZOE — a holistic platform beyond just glucose

ZOE is not just a CGM tracking startup — they go beyond glucose measurements to also test your gut microbiome and blood fat responses, too.

You might be wondering, wait a minute. Blood fat? What's that?

It turns out certain foods release fats that circulate in your blood for longer than others. Controlling blood fat levels helps reduce inflammation. You can see when fat is present in your blood:

Blood fat isn't typically measured because there's no good CGM equivalent for it yet. But ZOE incorporates finger blood pricks to get this data for you. The gut microbiome is also a fascinating health lever, which deserves an entirely separate post someday.

ZOE views personalized nutrition as a triad of the foods you eat, your metabolic health, and your gut microbiome. I happen to think this is the right approach, though communicating what the product does to people is likely much harder.

Cost: $294 +$29/month membership — note: ZOE is still an ongoing R&D company

What you get:

• CGM (14-day supply?)

• Finger prick tests for blood fats

• Gut microbiome test

• Controlled experiments via muffins (it's a long story...)

• Access to ZOE app and health coaching

On being a ZOE study participant (aka guinea pig)

I was a study participant of the Predict 2 study — run in collaboration with ZOE, Mass General, and Stanford. At the end of it, I received a 92-page report of my results. I can do a more in-depth writeup of my experience and what I learned, but here are some screenshots:

Each food was given a score out of 100, based on what I logged and the corresponding blood glucose and fat responses.

Vegetables and healthy fats (avocados, eggs) seem to be just fine with my body. Rice was a bit borderline, which I was sad about because I love rice.

My worst offender — potato chips... 🥔 🥲

Tastermonial — A/B testing foods with a CGM

Lastly, I include Tastermonial because it's a different business model than other CGM startups (Levels, NutriSense, etc.)

Their idea is to A/B test specific food products with a CGM. Tastermonial sends you a Taster Box and a prescription for a CGM sensor. Note that, unlike other companies, they don't send you CGMs. Instead, you need to go to a pharmacy to pick up a CGM yourself.

You then get to run your own glucose experiments using the foods they send you. For example, you may find that two similar nut bars produce different glucose responses for you:

This is a fascinating idea, though I've heard little about this company thus far. The price almost makes it too good to be true and I feel like there's a catch I'm missing. Maybe their app isn't as polished or it actually costs much more to buy the CGMs at a pharmacy than they are quoting? 🤷🏻‍♀️

Cost: ~$150 ($60 for TasterBox, ~$90 for two 14-day CGM sensors)

What you get:

• Curated box of packaged foods

• Prescription for 28-day supply of CGMs

• Access to Tastermonial app

Note: You need to provide the prescription to get CGMs from your local pharmacy.

The big picture

Overall, I believe that the future ecosystem of proactive wellness tracking — with continuous glucose monitoring in the epicenter — is a huge untapped market that most people don't realize. If done right, CGMs can be as commonplace as the Fitbit or Apple Watch.

I wrote this piece lightheartedly, but let's not forget the dire metabolic crisis we're in, especially in the United States. 1 in 3 American adults have prediabetes. Of those with prediabetes, more than 84% don't even know they have it. Plus, insulin consumption in the US is through the roof:

Image credit

If we continue to only focus on medication management for diabetes, this trend will only continue. Normalizing CGM use helps people learn how to make actionable dietary and lifestyle changes to bring Type 2 diabetes numbers down.

All right, I'm off my soapbox. May your glucose numbers be low and level — live long and prosper 🖖

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Thanks for reading!

Christina