A Cardiologist’s Thoughts on the Ketogenic Diet, Heart Disease & Metabolic Health: Ep 126

Doug Reynolds welcomes listeners back to the LowCarbUSA® Podcast with a guest who works in one of the most specialized—and most misunderstood—corners of cardiovascular medicine: the heart’s electrical system. 

Dr. David Nabert is an electrophysiologist (“EP” doctor), focused on heart rhythm disorders, and he’s one of the featured speakers at the Boca Symposium for Metabolic Health (January 23–25)—including the event’s full day-plus dedicated to cardiovascular conditions.

What gives this episode its pull is the combination of clinical depth and lived experience. David isn’t just talking about rhythm problems from a textbook perspective—he’s explaining how his own curiosity about metabolic health evolved, what shifted when he started questioning conventional assumptions, and why those questions matter for real patients in the real world.

David describes how his entry point into metabolic health didn’t begin in a clinic—it began with a random Google search.

In 2021, while looking up a cardiology formula, he accidentally landed on a Nina Teicholz talk at the Cato Institute. “I started to watch it, and all of a sudden, an hour and a half passed,” he says—one of those moments where interest turns into momentum. He listened to Teicholz’s book, The Big Fat Surprise, then began searching for more voices in the low-carb space and quickly reconnected with familiar names, including Dr. Robert Cywes and Dr. Eric Westman (both will also be presenting in Boca), whom he calls mentors. That exploration ultimately led him to the Society of Metabolic Health Practitioners (The SMHP) and, importantly, a willingness to test ideas on himself.

David is candid about his own weight journey. He describes a time when a body mass index under 25 felt “skinny” to him, and he’s open about losing weight, regaining some after a series of hip surgeries, and continuing to work on it. What ultimately shifted, though, wasn’t just the number on the scale—it was how he began to rethink what “doing everything right” actually means.

For years, he approached weight loss the way many clinicians were trained to: low-fat, high willpower, endure the hunger. He describes his old strategy bluntly: “The only way I had lost weight… was by doing protein sparing modified fast… I was just eating almost no fat.” Predictably, it wasn’t sustainable. When he later shifted to a lower-carb, higher-fat approach—“bacon, eggs, hamburger”—he was “amazed at how quickly I started to lose weight,” and he began seeing changes in markers that traditional cardiology often de-emphasizes.

After stopping long-term statin therapy (which he had been on for 25 years), he saw his LDL return to roughly where it had been earlier in life, but other changes caught his attention: triglycerides dropped to the lowest he’d ever seen, HDL improved, and fasting insulin improved as well. Just as meaningful were the changes he felt: “Every 10 or 20 pounds I lost, my hips got better,” he says, attributing it not only to less load, but “also part of it was less inflammation.”

From there, the episode moves into the heart of why David is speaking during the cardiovascular-focused programming in Boca: rhythm, electricity, and the surprising overlap between conditions that seem unrelated—like seizures and arrhythmias.

David explains that early ketogenic diet research in the 1920s focused on refractory seizures, and he argues the connection matters because many antiarrhythmic drugs and antiseizure drugs overlap mechanistically. In his view, these aren’t separate worlds. “Treating seizures or treating cardiac arrhythmias is basically two faces of the same coin,” he says—and that opens a practical question: if ketosis can help reduce seizures, might it also influence certain rhythm symptoms?

He shares a striking clinical example that stuck with him: a former submariner with PTSD and episodes of fast heart rates who said, “I know when I’m… ketogenic… when I fall off the wagon… then I start having palpitations and fast heart rates.” David later learned the patient was experiencing atrial fibrillation, and while he’s careful not to overpromise, he describes a pattern he’s observed: in earlier stages of rhythm problems, being in a ketogenic state may reduce symptoms and potentially slow progression for some people. “It doesn’t cure atrial fibrillation,” he emphasizes, but he’s seen ketosis “improves symptoms,” not only in AFib, but in other rhythm issues like SVT and PVCs—especially early on.

From there, David widens the frame to what he’s seeing in younger patients—particularly young women—showing up with palpitations, rapid heart rate, anxiety, and signs of metabolic dysfunction even when they don’t “look” unhealthy by BMI alone. “Only 90% of them are metabolically unhealthy,” he says, describing a familiar cluster: A1C not quite normal, resting heart rates high, daytime heart rates that shouldn’t be running 100–120, and a nervous system dialed up in what he calls a “hyper adrenergic state.” The mainstream response is often medication—beta blockers, for example—but David argues metabolic context matters, and he’s exploring how nutritional strategies (including ketosis, sometimes even supplemental ketones) may reduce symptom burden in certain cases.

He also discusses POTS (Postural Orthostatic Tachycardia Syndrome), noting it can be associated with viral infections and has become more common since “the bad virus we had five years ago.” Again, he’s measured in his claims: ketosis isn’t a cure, but he’s seen it help reduce symptoms in select patients who have tried many other standard approaches first.

The second half of the conversation touches on medications and the tension between “lower the number” cardiology and whole-person outcomes. David brings up PCSK9 inhibitors and recalls being troubled by early data patterns: “You were less likely to die from that, but you’re more likely to die from cancer or infection… And… the overall mortality was the same.” That line of thinking captures what pushed him toward metabolic health: a concern that focusing on a single marker can obscure the bigger picture of risk, resilience, and long-term outcomes.

He also discusses SGLT2 inhibitors (like Jardiance and Farxiga) as potentially useful tools—especially in heart failure and diabetes—while stressing the importance of monitoring and hydration. In a moment that captures both his clinical caution and his enthusiasm for empowered patients, he tells people who go low carb on these meds to “get a Keto Mojo to check your ketone levels,” because the goal is to use tools intelligently, not blindly.

As the episode closes, Doug returns to the bigger mission behind the upcoming Boca program: helping attendees develop a confident, educated response to the most common fear tactic people face when they change their diet—LDL, heart attacks, and the assumption that low carb automatically means danger. Doug notes there are still “so few that really do get it and support it and talk about it,” which is exactly why the cardiovascular-focused day-plus at the Boca Symposium for Metabolic Health (January 23–25) matters.

David, for his part, is grateful to be part of it—and to be healthy enough to show up differently than last time. He reminds Doug that at previous events he was “either walking with one or two canes,” but now, “I’m actually not going to run up on the stage, but I’ll be moving pretty quickly.”

That moment captures the heart of the episode: metabolic health isn’t theoretical. It’s lived. And in Boca, that lived experience meets serious clinical discussion—especially for anyone trying to better understand cardiovascular risk, rhythm disorders, and the metabolic foundations that too often go unaddressed.

If this conversation sparks your curiosity, the next step is obvious: join the community in Boca January 23–25 and immerse yourself in a day and a half of cardiovascular-focused talks designed to help you think more clearly, speak more confidently, and act more effectively—whether you’re a clinician, a patient, or someone trying to help the people you love.

Learn more about the Boca Symposium and register here.