When did obesity become a drug deficiency?

The 2026 American Diabetes Association Standards of Care therefore recommend continuing obesity pharmacotherapy beyond achievement of weight-loss goals when indicated for chronic therapy, noting that discontinuation often results in recurrent weight gain and reemergence of cardiometabolic risk factors.[16] The World Health Organization likewise now states that GLP-1 therapies may be used as long-term treatment for adults living with obesity. However, its recommendation is conditional and recognizes the need for comprehensive behavioral and lifestyle intervention.[17]

Yet, obesity differs from many chronic diseases in one important respect: its prevalence changed dramatically within a remarkably short historical period. That should make us cautious about letting "chronic disease" end the discussion. If the environment continually pushes human metabolism toward excess adiposity, and a drug successfully counteracts that pressure only while it is administered, lifelong pharmacotherapy may be entirely appropriate for some patients. But it should simultaneously intensify our interest in the pressure itself. Otherwise, we risk defining successful medicine as the indefinite pharmacological adaptation of human beings to an unhealthy environment.

Losing weight is not the same as losing fat

Another part of this conversation deserves more attention, particularly as these medications expand into older populations. Large reductions in body weight do not consist exclusively of adipose tissue. During weight loss, some lean tissue is generally lost as well, regardless of whether weight reduction occurs through caloric restriction, surgery, or pharmacotherapy. The relevant question is not whether lean mass changes, but how much is lost, in whom, and what the functional consequences may be.

A DXA substudy of SURMOUNT-1 found that participants receiving tirzepatide experienced a 21.3 percent reduction in body weight, accompanied by a 33.9 percent reduction in fat mass and a 10.9 percent reduction in lean mass. Approximately three-quarters of the lost weight was fat, and one-quarter was lean mass.[18] That is a far more nuanced finding than the popular claim that GLP-1 drugs "destroy muscle."

They do not. Body composition generally improves because more fat than lean tissue is lost proportionally. Nevertheless, lean tissue is biologically important, and its loss should not be treated as irrelevant simply because the scale is moving in the desired direction.

This is especially important in older patients, in whom sarcopenia, frailty, falls, osteoporosis, and loss of functional independence already represent major clinical concerns. Skeletal muscle is not decorative tissue. It is central to glucose disposal, mobility, balance, strength, metabolic reserve, and resilience during acute illness.

A 35-year-old with severe obesity losing some lean mass during substantial fat reduction is not clinically equivalent to a frail 78-year-old doing the same. Responsible obesity medicine therefore cannot consist simply of prescribing an injection and celebrating weight loss. Nutrition, adequate protein intake, resistance exercise, physical function, and muscle preservation should become integral parts of treatment. The goal is not to make patients lighter. The goal is to make them healthier.

The economics of treating the consequence

This discussion has an uncomfortable economic dimension that does not require conspiracy theories or accusations of bad faith. Modern health care is exceptionally effective at creating financial structures around treatment. A pharmaceutical product can be researched, patented, manufactured, marketed, prescribed, reimbursed, monitored, and administered repeatedly. Hospitals can build programs around it. Insurers can establish coverage criteria for it. Physicians can prescribe it. Investors can calculate its market. Patients can measure its effects. The entire structure of modern medicine understands how to assign economic value to an intervention.

They did not have continuous glucose monitors, smartphone applications that counted calories and macronutrients, wearable devices reminding them to stand, boutique fitness studios, bariatric surgery centers, or medications capable of producing 15 or 20 percent reductions in body weight. They were not necessarily more virtuous than we are, and they certainly did not possess superior genes. They lived in a different metabolic environment.

The data backs up what we see in those old photos. In the early 1960s, about 13 percent of American adults were obese. By August 2023, that number had jumped to 40.3 percent, with another 31.7 percent considered overweight and nearly one in ten classified as severely obese.[1] This trend isn't just in the United States. A huge study of over 220 million people from 200 countries found a dramatic global rise in obesity between 1990 and 2022.[2] Our genes haven't changed much in that time. Something else has.

We're now at a turning point in medicine. Faced with one of the biggest and fastest changes in human health, we're treating the results as a condition that needs lifelong medication. The newest drugs are very effective, and that's important to recognize. Semaglutide and tirzepatide have led to weight loss that older nonsurgical treatments rarely matched.[3,4] Semaglutide has also reduced the risk of major heart problems in people with overweight or obesity and heart disease who didn't have diabetes.[5] Tirzepatide has greatly improved sleep apnea in people with obesity.[6] These results are significant, and these drugs are much more than cosmetic weight-loss aids.

That's why we need to look closely at what's happening now. The problem isn't that these drugs don't work; they clearly do. The real concern is that they might work so well that we stop asking why so many people need them in the first place. We could be seeing a major medical breakthrough, but at the same time, we might be accepting that the effects of an unhealthy environment should just be managed with medication. The real question isn't whether these "GLP-1" drugs are effective. It's whether their success is making us stop looking for the root causes of the obesity epidemic.