I've now written about metabolic health as the baseline, and obesity as its most visible expression. This post is about widening the lens. Obesity is one expression of metabolic dysfunction, not the whole condition — and I think that distinction matters more than it gets credit for.
The umbrella term, defined
Metabolic disease is the broader category that obesity sits inside. It refers to any breakdown in the systems that regulate how your body produces, stores, and uses energy — appetite signaling, insulin function, fat storage and distribution, and the inflammatory and hormonal processes that coordinate all of it. Obesity is one visible consequence of that breakdown. Type 2 diabetes is another. So is metabolic syndrome, which I'll cover specifically in an upcoming post, and so, in a more insidious way, is the fatty liver disease I'll also be writing about soon.
Here's the part I think gets missed most often: these aren't separate conditions that happen to occur together. They're different downstream expressions of the same upstream dysfunction. A patient can have significant metabolic disease with a completely normal body weight. I've seen this more times than I can count — a patient whose weight looks unremarkable on paper, but whose blood work tells a very different story: elevated fasting insulin, borderline glucose, inflammatory markers that shouldn't be where they are for someone their age. Weight and metabolic disease correlate strongly, but they are not the same thing, and treating them as interchangeable causes real diagnostic blind spots.
Why the same root cause shows up so differently
If metabolic disease is really one underlying phenomenon, why does it show up as obesity in one patient, diabetes in another, and normal-weight metabolic dysfunction in a third? A few things drive that variability, based on what I've seen across thousands of surgical patients and hundreds treated medically:
Genetics and individual physiology. Some people are predisposed to store excess energy as visceral fat. Others are predisposed toward insulin resistance without significant weight gain. The same underlying dysregulation can express itself through different pathways depending on a person's biology.
How long the dysfunction has been present. Metabolic disease is rarely sudden. It tends to build over years, sometimes decades, and which system shows visible strain first — fat storage, blood sugar regulation, the liver — varies from person to person.
What compensatory mechanisms are still working. The body has significant capacity to compensate for early dysfunction before anything shows up on standard testing. Two patients with similar underlying dysregulation can look very different clinically simply because one has more compensatory reserve left than the other.
Why this matters for how I evaluate a patient
This is a big part of why I don't treat a patient's weight, on its own, as the full clinical picture. A patient who is not "overweight" by conventional standards can still have significant metabolic disease that deserves treatment. And a patient who is significantly overweight might have relatively preserved metabolic function, which changes what I'd prioritize in their care.
The practical implication is that metabolic disease needs to be evaluated directly — through markers like fasting insulin, inflammatory markers, liver enzymes, and body composition, not inferred from weight or BMI alone. This is the same principle behind why I send patients for DEXA scans between visits, extended to the broader picture: the number that's easiest to measure is rarely the number that tells you the most.
Where this is headed
Over the next several posts, I'm going to work through the specific expressions of metabolic disease individually: metabolic syndrome as a formally diagnosable cluster, chronic inflammation as a connecting mechanism running underneath nearly all of it, visceral fat and fatty liver disease as concrete, visible consequences, and muscle loss and fitness decline as both causes and consequences of the same underlying dysfunction. Each of those posts will stand on its own, but I wanted this one to come first, so the connections between them are clear before we get into the specifics.
The throughline I'd want you to carry forward: metabolic disease is not a single symptom to chase down. It's a systems problem, and it deserves to be evaluated and treated like one.
Curious what your own metabolic markers actually look like, beyond weight? [Reach out / subscribe / etc. — placeholder for your CTA.]
Medical disclaimer: This content is provided for general educational and informational purposes only and does not constitute medical advice. It is not intended to diagnose, treat, cure, or prevent any condition, and it does not create a physician-patient relationship. Every patient's medical history, health status, and treatment needs are different. Always consult your own physician or qualified healthcare provider before starting, stopping, or changing any medication or treatment, and before making any decisions based on information found here. If you are experiencing a medical emergency, call 911 or go to your nearest emergency room.