When did obesity become a drug deficiency?

Second, a civilization in which enormous numbers of people may require lifelong pharmacological manipulation of appetite and metabolism to maintain health should be intensely curious about how that situation arose. Calling obesity a chronic disease does not relieve us of that responsibility. If anything, the scale of the disease makes the responsibility greater.

We should therefore reject the false choice between treating obesity and preventing it. Physicians must treat the patient standing in front of them with the best tools available today. Scientists and public health institutions must also investigate why so many patients present with the same problem.

Government should evaluate whether policies affecting food, cities, schools, physical activity, sleep, and environmental exposures promote metabolic health or undermine it. Medicine should study not merely how efficiently we can produce weight loss, but whether we can preserve muscle, metabolic health, function, and independence while doing so.

The question our grandchildren may ask

Medical history is filled with treatments that became so familiar that physicians stopped asking the questions that originally justified them. Sometimes the treatments were eventually shown to be wrong. Sometimes they were useful but applied too broadly. And sometimes the treatment worked exactly as intended while distracting medicine from a more fundamental cause of disease. The GLP-1 revolution may ultimately belong to an entirely different category: therapies that are genuinely transformative and beneficial, but whose very effectiveness risks concealing the magnitude of the societal failure that made them necessary.

Imagine medicine 20 or 30 years from now. The drugs will almost certainly be better. Oral formulations, combinations of incretin and other metabolic pathways, agents that better preserve lean mass, and therapies we cannot yet imagine may make obesity increasingly controllable. Perhaps cardiovascular disease and diabetes will decline dramatically as a result. That would be a genuine triumph of medical science.

But imagine another possibility as well. Suppose half of the adult population requires continuous pharmacological intervention to maintain metabolic health while children continue entering the same environment that produced the epidemic.

Suppose we become extraordinarily proficient at altering the individual's biology while leaving the biology-disrupting environment essentially untouched. Would we call that prevention? Would we call it health? Or would we have become very good at treating the consequences of something we never dared to confront?

Those are not reasons to take an effective drug away from a patient who needs it. They are reasons to refuse the complacency that can accompany therapeutic success. The physician's responsibility is to treat disease. Medicine's responsibility is larger. It must also remain curious about why disease occurs, particularly when its prevalence changes before our eyes.

The great irony of the GLP-1 era may therefore be that the medications are not the problem at all. They may be among the best tools we have ever developed for treating obesity. The real problem will arise if their success convinces us that the epidemic itself has been solved. A weekly injection can change appetite, body weight, glucose metabolism, cardiovascular risk, and perhaps the trajectory of an individual patient's life. What it cannot do is explain why a condition that affected a relatively small minority of Americans 60 years ago now affects roughly four in ten adults.

We should use these medications when they improve our patients' lives. We should study them rigorously, monitor their long-term consequences, make access rational and equitable, and resist both their demonization and their indiscriminate use. But every prescription should coexist with a much larger scientific question, one that medicine should have been asking with far greater urgency for decades: what did we change that made so many people sick?

The tragedy of the GLP-1 era will not be that these drugs failed. The tragedy will be if they succeed so spectacularly that an entire generation of physicians stops asking why we needed them in the first place.