Metabolic health is having a moment.
You see it all over social media. There are startups marketing blood tests and full-body DEXA scans, influencers debating mitochondrial density, and celebrities wearing continuous glucose monitors while eating steak and tweeting about seed oils.
It feels like everyone is suddenly an expert.
But what is metabolic health, really?
Metabolic health is simultaneously incredibly important and incredibly poorly understood - often by the people who harp the most on its importance.
The goal of this post is to demystify metabolic health as a practical concept: Why does it matter? How do you measure it? Is your own personal metabolic health good or bad?
Metabolic syndrome is the concept you need to know to understand metabolic health
Most doctors are familiar with metabolic syndrome. It’s not new. In fact, the concept was first described in the 1980s by Gerald Reaven, who called it “Syndrome X.” It’s a constellation of risk factors that includes:
Elevated triglycerides
Low HDL cholesterol
High blood pressure
Abdominal obesity
Elevated fasting blood sugar
If you have three of the five, you meet criteria for metabolic syndrome.
Through this lens, the concept of metabolic health is simple - good metabolic health keeps you free of metabolic syndrome.
And the opposite holds, too. Bad metabolic health means you’re on the road to metabolic syndrome.
I often think of metabolic syndrome as the precursor to prediabetes. Just like prediabetes is a step away from having diabetes, metabolic syndrome is a step away from prediabetes.
My mental model: metabolic syndrome = pre-prediabetes.
But that’s not the entire story, because meeting criteria for metabolic syndrome doesn’t tell you anything about the underlying physiology, it’s just the result that you see on testing.
You can have poor metabolic health and not meet criteria for metabolic syndrome.1
And it’s partly because of that gap - the clinical syndrome versus the underlying biology - that the concept can feel so nebulous.
And keep in mind that poor metabolic health is a big deal - like high blood pressure or high cholesterol - for 2 major reasons:
Having poor metabolic health has a huge impact on your risk of heart attack, stroke, and probably Alzheimer’s disease
You don’t have any symptoms of it and you can’t tell without doing some medical testing.
The Clinical vs. Influencer Divide
Metabolic syndrome has been in the medical literature for decades. It’s not obscure. And it’s not something the traditional healthcare system missed. But it is something that often gets ignored in practice, which is a problem.
Why?
Because medicine tends to focus on things we can treat. We have meds to lower blood pressure. We have meds to lower blood sugar. We have injections that help you lose weight.2 We don’t have a pill that improves “metabolic health.”3
Doctors talk more about diabetes and hypertension than the subtle signs of poor metabolic health because it’s not clear whether treating metabolic health with prescription medications actually makes anyone feel better or live longer.
And a lot of things that help metabolic health - like exercise, diet, sleep - are things that a good doctor discusses, but then it’s up to each patient to take action in their own lives outside the clinic.
Remember, metabolic health exists on a continuum, and there are often signs apparent in your bloodwork long before you develop hypertension or diabetes.
The Popular Rebranding
In the wellness and DTC world, metabolic health has become a catchall term. It includes everything from insulin resistance and blood sugar control to inflammation, fatty liver, mitochondrial function, and visceral fat.
And while some of that is grounded in biology, a lot of it is just buzzwords.
Influencer “explanations”4 often sound like word salad: mitochondrial optimization, glucose spikes, metabolic flexibility, autophagy.
The truth is: there’s no single definition of metabolic health. We don’t have any agreed-upon diagnostic test. And there’s certainly no universal score.
There are metrics that can help:
Fasting glucose
Hemoglobin A1c
Triglycerides / HDL ratio5
Waist-to-hip ratio
Fasting insulin
ALT and AST (for fatty liver)
Uric acid
But even among those, there’s variation in interpretation and no unified threshold. Remember, metabolic health exists on a continuum.
And the lack of an easy definition of “good” metabolic health makes the topic ripe for confusion and misinformation.
Insulin Resistance: the Core Problem
The underlying problem in metabolic syndrome is insulin resistance.
Insulin is the major hormone that regulates blood sugar, and as we become resistant to insulin, it takes higher and higher amounts to keep our blood sugar in check.
Hyperinsulinemia is what drives the bad outcomes linked to poor metabolic health - heart disease, cancer, and cognitive decline.6
But you can be incredibly insulin resistant (meaning your metabolic health is very poor) and still not meet the diagnostic criteria for diabetes.
If your pancreas is capable of pumping out increasing amounts of insulin without burning out, you can have awful metabolic dysfunction but keep your sugars somewhat in check.
That’s because diabetes doesn’t happen from insulin resistance. It happens when the pancreas fails - when beta cells burn out and can’t keep up with the ever increasing insulin demands.7
What Ozempic Teaches Us About Metabolic Health
The incretin mimetics like Ozempic, Wegovy, and Zepbound have changed the metabolic health landscape.
They’re the first drugs to work at scale to treat metabolic dysfunction.
And seeing their success in improving biomarkers of metabolic syndrome has led me to update my mental model of metabolic health a bit.
I still think of metabolic syndrome as pre-prediabetes. But I now think of the insulin resistance that underlies it as energy toxicity.
These drugs reduce appetite and lead to weight loss through spontaneous reduction in calorie intake - they directly reduce energy toxicity.
That’s why these drugs can be such powerful tools in our arsenal against metabolic syndrome.
And when I’m thinking about how strongly to recommend these drugs for patients who are overweight or obese, but don’t have diabetes, I’m looking at biomarkers of metabolic dysfunction to help guide that discussion.
CGMs: The Popular Tool That Might Not Help
It was notable to see RFK point to wearable devices as key to the MAHA agenda, because that means a lot of money for people who sell CGMs, like the nominee for surgeon general.
Continuous glucose monitors (CGMs) have become wildly popular among the health-optimization crowd. The idea is simple: watch your blood sugar rise and fall after meals, and learn what’s “good” or “bad” for you.
But in non-diabetics, CGM data is mostly confusing and poorly validated.
I’ve worn one myself. What did I learn?
That high-carb meals cause glucose spikes? Sure.
That stress or poor sleep raises fasting glucose? Okay.
That blood sugar drops quickly after a spike? Yes… and?
But do those spikes matter?
Is the area under the curve for a post-meal spike meaningful? Is the number of spikes per day predictive of disease? What about time-of-day effects? Glycemic variability?
Or is it all just unimportant noise?
If a CGM helps you change your own behavior, great - but that assumes that the behavior changes it drives are actually helpful.
After all, bacon doesn’t cause a glucose spike but blueberries do. Are we sure we want to incentivize choices based on that?
None of that has been convincingly shown to affect hard outcomes in people without diabetes.
So what you’re left with is a device that produces a lot of data… and not much insight.
Worse, it gives the illusion of understanding.
And mechanistic plausibility isn’t the same as evidence.
Is It Really That Complicated?
Not really.
If you want a decent snapshot of metabolic health, you don’t need a CGM or a DEXA scan or a 100-lab panel from Function Health.
You can look at:
Waist-to-hip ratio
Fasting glucose and fasting insulin
Triglycerides and HDL
Blood pressure
Hemoglobin A1c
These are standard, accessible, and informative.
Do they tell the whole story? No. But they’re more than good enough for most people. And they’re the basis for what Gerald Reaven described 40 years ago.
That’s the irony: what I see on social media (and what my patients hear) makes metabolic health sound like a brand-new discovery.
Metabolic health isn’t some new frontier that traditional medicine ignored.
It’s something we’ve known about for decades. It just didn’t come with a subscription box or a viral podcast segment.
The Public Health Side
It’s easy to make this about personal responsibility. And behavior change does matter.
But metabolic dysfunction is also a structural problem.
We subsidize processed food. We build cities for cars, not walking. We prioritize short-term productivity over sleep and stress reduction. We don’t incentivize primary care, and we don’t incentivize lifestyle medicine.
The result is predictable: most people are metabolically unhealthy not because they’re lazy or ignorant, but because the default choices in their environment are unhealthy ones.
We need to acknowledge that when we talk about solutions.
What Actually Works
So what improves metabolic health?
Consistent physical activity
Building and preserving muscle mass
Not eating too much food
Managing stress and improving sleep
Targeted medications for those who need them
That’s not sexy. And talking about it isn’t going to grow your follower count.
But it works.
Final Thought
Metabolic health is real. But it’s not magic. And it’s not new.
The clinical concept has been around for decades. What’s new is the marketing.
There’s nothing wrong with being curious or with using tools that help you feel more in control.
But don’t confuse novelty with insight.
You don’t need a glucose monitor to know that cupcakes aren’t health food. You don’t need an oral glucose tolerance test to know you should move your body and sleep more.
Metabolic health doesn’t require a PhD in mitochondrial biogenesis. It just requires doing the basics consistently.
And maybe, not getting distracted by all the noise.
The reverse isn’t really true - it’s almost impossible to have metabolic syndrome and have good metabolic health.
And losing weight improves metabolic health. But good luck getting insurance coverage for Wegovy with “metabolic health improvement” in your prior authorization.
Unless you count drugs like Ozempic and Zepbound. I think it’s debatable whether metformin really does improve metabolic health (it might). And drugs like pioglitazone, which actually treat insulin resistance effectively, are drugs that we give to patients with diabetes, not people with metabolic syndrome.
You’ve probably noticed that I’m talking a lot about influencers in this newsletter. That’s for two reasons. First, I hear a lot from my patients about how they are influenced by what they see on social media. Every single buzzword that I’m writing is something that I’ve had a patient say to me. Second, the MAHA movement - currently, our mainstream public health ethos - gets a lot of their ideas from the same miasma of science-adjacent content that drives the influencer economy.
I wrote about the triglyceride to HDL ratio in this post:
But fasting insulin levels on their own don’t necessarily tell the whole story. You can have considerable insulin resistance before fasting insulin levels actually rise. And the mechanics of measuring the rise in insulin in response to an oral glucose tolerance test is impractical for almost everyone.
That’s why people with Type 2 diabetes often need insulin therapy down the line, even though their bodies produce insulin.