About

Headwaters is an independent publication about the emerging future of metabolic medicine—what the science is teaching us, how new therapies are changing what is possible, and how we build systems of care capable of translating that progress into better health.

I’m David Brennan, MD, a physician and clinical leader whose work sits at the intersection of obesity and metabolic disease, clinical care, population health, research, health-system strategy, technology, and innovation.

Much of my professional work involves a question that has become increasingly difficult to ignore: What happens when our ability to treat metabolic disease advances faster than the systems we have built to deliver that care?

The incretin era has made that question especially urgent. Treatments developed for diabetes and obesity are now affecting cardiovascular disease, heart failure, sleep apnea, liver disease, kidney disease, and other conditions across multiple organ systems. At the same time, our understanding of metabolic health is expanding beyond body weight alone to include function, fitness, disease prevention, quality of life, and longer-term health outcomes.

That creates both scientific opportunity and practical complexity.

Through Headwaters, I plan to explore that intersection.

What I write about

My interests span three broad areas:

Science — What does the evidence actually show? Which findings are mature enough to change practice, and which remain preliminary, observational, or mechanistic?

Systems — What happens when promising science meets real patients, clinical workflows, benefit design, affordability constraints, workforce limitations, and the realities of healthcare delivery?

Strategy — If metabolic medicine is becoming a broader and more consequential field, what should clinicians, health systems, employers, payers, researchers, and innovators begin doing differently?

I am particularly interested in questions that do not fit neatly inside a single specialty: how we define meaningful outcomes beyond weight; how metabolic therapies affect diseases across organ systems; how fitness and function should fit into treatment goals; how we use increasingly powerful therapies responsibly; how technology can support longitudinal care; and what an integrated model of metabolic medicine might ultimately look like.

The goal is not to chase every new study or headline.

It is to identify developments that matter, examine the evidence with appropriate skepticism, and connect scientific progress to the decisions that clinicians and healthcare leaders actually have to make.

Why Headwaters?

I live and work in Minnesota, home to the headwaters of the Mississippi River.

Near its beginning, the Mississippi looks remarkably different from the immense river it eventually becomes. Yet what begins upstream can profoundly shape what happens far downstream.

That idea resonates with how I increasingly think about metabolic health.

Many of the diseases medicine encounters downstream—cardiovascular disease, diabetes, liver disease, sleep apnea, kidney disease, and others—are influenced by metabolic processes that begin much earlier and cross traditional specialty boundaries.

The metaphor is imperfect. Human biology has no single headwater, and chronic disease is shaped by genetics, biology, behavior, environment, social conditions, and many other forces.

But the central question is useful:

What becomes possible if we get better at understanding—and treating—what is happening upstream?

That is the territory I hope to explore here.

About me

I am a physician at Mayo Clinic, where my work includes clinical leadership in weight management and metabolic health. I also work at the intersection of clinical care and healthcare innovation, including with Mayo Clinic business venture Metriana.

Those experiences inevitably influence the questions I ask, but Headwaters is my independent professional publication. It is not an official Mayo Clinic or Metriana publication, and the views expressed here are my own.

I intend to be transparent about relevant professional relationships and conflicts of interest when they intersect with subjects I write about. Additional information is available on the Disclosures page.

If you are interested in the science, systems, and strategy shaping the future of metabolic medicine, I hope you’ll follow along.