I’ve been doing this long enough to have believed in technologies that failed, and doubted technologies that succeeded. That is a humbling education, and it is the one I trust most.

I watched the Prostatron arrive, microwave thermotherapy that was going to spare men the operating room for their prostates. It had its moment, and then the moment passed. I watched Computer Motion’s ZEUS, a surgical robot of real elegance (the machine behind Michel Gagner’s transatlantic gallbladder operation), lose its race and get absorbed into history. I was not a bystander to any of this. I introduced laparoscopic radical prostatectomy to this country (performed the first case, wrote the technical manual) before the robots did. So I say the following with affection for the whole enterprise, not contempt: Medicine falls in love with the dazzling number, and the dazzling number is often the wrong one.

Here is the pattern I’ve come to recognize. A new technology or metric appears. It is easy to grasp, easy to measure, easy to sell. It promises more: more precision, more speed, more of whatever we were already chasing. And in the rush toward more, we forget to ask the harder, quieter question: More of what, and is it the thing that actually matters to our patients?

I learned the value of that quieter question the hard way. Years ago, as a co-investigator and co-author, I helped Larry Clark conduct the first human trial ever to show that a dietary supplement could prevent cancer, an unglamorous question in an era enamored of treatment. Prevention is not a dazzling number. It is slow, it is undramatic, it does not photograph well. But it was the right question, and asking the right question is worth more than a decade of chasing the wrong one impressively.

I see the same drama playing out now in the field everyone is watching: obesity and metabolic medicine. And I see us, once again, mesmerized by quantity.

The number we chase is how much. How many pounds, what percent of body weight, how much fat is gone. It is the easiest thing to measure and the easiest thing to celebrate, and in an era when we can move that number almost at will, we celebrate it constantly. But a career spent distrusting the dazzling metric makes me want to ask the other question: not how much fat, but what kind, and where.

Because fat is not one thing. The fat stored under the skin of the hips and thighs is, metabolically, nearly inert. The fat that collects inside the abdomen and infiltrates the organs, the so-called viscera (the liver, the heart, the pancreas), is something else entirely: metabolically active, inflammatory, spilling free fatty acids and signaling molecules into the portal circulation, driving insulin resistance and cardiovascular risk. Fat even infiltrates skeletal muscle itself (myosteatosis), which is not a cosmetic detail but a marker of insulin resistance, poor metabolic health, and poor clinical outcomes across a striking range of conditions. Two people can carry the identical quantity of fat and face entirely different futures depending on its quality: its location, its behavior, its inflammatory temperament. This is not fringe science; it is decades of adipose physiology that our obsession with the scale keeps burying.

Which raises a possibility our quantity-fixation makes us slow to see: that where fat sits may matter as much as whether it leaves. That shifting fat out of the dangerous depots (improving its distribution and its quality) could be as consequential as gross loss, and sometimes more. A patient can lose a great deal of weight and remain metabolically imperiled if the wrong fat stays. A patient can lose relatively little and improve profoundly if the right fat moves. The scale cannot tell those two stories apart. It only counts.

I am not romanticizing difficulty for its own sake. Quantity is worth measuring, and the powerful new tools that produce fat loss are among the most important advances of my career; I am glad patients have them. But quantity is the seductive metric (easy, legible, marketable), and quality is the true one, harder to measure and harder to sell. Every technology I watched rise and fall taught me the same lesson: The thing that dazzles is not always the thing that lasts, and the number everyone chases is not always the number that matters.

So when I look at the metabolic revolution unfolding around us, I find myself asking the quiet question again. Not how much fat we can make disappear (we are getting very good at that), but what kind of fat, in what places, doing what to the body. Quality, not quantity. It is the less glamorous question. In my experience, it is usually the right one.

Arnon Krongrad is a surgeon-scientist in South Florida. In 1999, he became the first surgeon to perform laparoscopic radical prostatectomy in the United States, and he coauthored Laparoscopic Radical Prostatectomy: A Technical Monograph, which standardized the operation now performed robotically worldwide. A board-certified urologist, he founded the Krongrad Institute, America’s longest-running program devoted to the procedure.

His basic and clinical research has appeared in JAMA and Cancer Research, and he was a coauthor on Larry Clark’s landmark selenium trials, among the first to show that a dietary supplement could reduce cancer incidence. His current research centers on metabolic health, including early-stage clinical trials of the peptide Pep19 in adults with obesity, with results published in Diabetes/Metabolism Research and Reviews and forthcoming in iScience.

He earned his BA in chemistry at Columbia College and his MD at the College of Physicians & Surgeons, completed a surgical internship at the University of Hawaii and a urology residency at Mount Sinai Medical Center, and completed a fellowship in endocrinology and metabolism at UT Southwestern Medical Center.

He is a cofounder and chief medical officer of Proteimax Biotechnology, a peptide discovery company focused on metabolic health, and founder of Ezz, a knowledge club devoted to maximum health. He shares updates on LinkedIn and X.