Should We End Obesity?

It’s unusual for a medication to become a household name; even more uncommon for its branding to become, like Advil, shorthand for an entire class of products; and rarest of all, for it to change not just U.S. medicine, but U.S. culture.

Ozempic has done all three.

Approved in 2017 as a type 2 diabetes medication, Ozempic has largely made its name—and a fortune for its manufacturer, Novo Nordisk—as a weight-loss aid. Novo Nordisk knew early on that diabetes patients often lost weight on the drug, but even company executives couldn’t have guessed how widely it would eventually take off as both an off-label anti-obesity treatment and a vanity-driven status symbol for those simply looking to shed a few pounds. Its runaway success mirrors that of similar medications, including Eli Lilly’s Mounjaro and Wegovy, another Novo Nordisk product and the only one in the trio technically approved for weight loss. Prescriptions for all of them are flying off the pad at an eye-popping rate.

Novo Nordisk sold around $14 billion of its various diabetes and obesity drugs in the first half of 2023, and Eli Lilly sold almost $1 billion worth of Mounjaro in a single quarter this year. Prescriptions for these weight-loss meds are up 300% since early 2020, with more than 9 million written in the U.S. in the last three months of 2022 alone, according to health care industry research firm Trilliant Health. Demand is so great that Ozempic, Wegovy, and Mounjaro have all recently gone into shortage, and patients with type 2 diabetes have in some cases struggled to fill their prescriptions as they compete for limited supplies with people looking to slim down; meanwhile, spas, internet suppliers, and compounding pharmacies are all fighting for their piece of the Ozempic pie.

No one can quite agree on whether this frenzy is a good thing. Plenty of physicians (and, of course, the pharmaceutical executives who stand to get very, very rich) say it is, given that roughly three-quarters of U.S. adults qualify as either overweight or obese and are thus, according to leading public-health authorities, at risk of a range of serious health complications. “Obesity is an epidemic, and we urgently need effective treatments,” says Dr. Sahar Takkouche, an obesity and bariatric medicine specialist at Vanderbilt Health.

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But some doctors, researchers, and activists are uneasy about living in the age of Ozempic—one that has felt like a kind of deja vu, a return to an era when thinness and weight loss were unquestioningly valued. Before the Ozempic tsunami, a growing number of doctors and researchers had begun advocating for Health at Every Size, a research-backed set of principles from the Association for Size Diversity and Health that hold body size is not a measure of health or worth, and that all people deserve high-quality, non-stigmatizing medical care. Their efforts contributed to a burgeoning field known as “weight-neutral” medicine, which sees “weight” and “health” as separate, and worked in tandem with the wider body-positivity movement to help loosen the diet industry’s vice-like grip on American psyches. As the 2000s progressed, women’s magazines stopped pushing diets quite so hard. Clothing brands bragged about hiring models larger than a size 0. Even Weight Watchers rebranded as a “wellness” company called WW.

Then Ozempic and its cohort came along, and it turned out lots of people still wanted to be skinny. Some industry watchers have even predicted that the rise of drugs like Ozempic—and an impending crop of new, potentially more effective, competitors including Eli Lilly's newly approved offering, Zepbound—could spell the end of obesity. But as these drugs transform both standard medical practice and cultural ideas about weight loss, a contentious debate is simmering beneath the surface: should we even be treating obesity?

The U.S. medical establishment is clear about its stance on obesity: it is a “common, serious, and costly chronic disease,” as the U.S. Centers for Disease Control and Prevention puts it. By CDC estimates, more than 40% of U.S. adults and almost 20% of children and adolescents are obese, putting them at risk of health problems including heart disease, type 2 diabetes, stroke, and certain types of cancer. An additional 30% of adults are considered overweight, meaning less than a third of U.S. adults meet the CDC’s standard for a healthy body weight.

If obesity is a disease, it follows logically that it should be treated. Historically, diet and exercise have been plan A for treating obesity. But in practice, lifestyle changes like these often aren’t enough. “Try as we might, a lot of exercise typically does not result in a significant amount of weight loss,” says Glenn Gaesser, a professor of exercise physiology at Arizona State University. That’s in part because people tend to get hungrier the more they move, offsetting whatever calories they burn at the gym, and in part because the body gets used to its size and works to stay at that set point, Gaesser explains. Lifestyle fixes can work for some people, studies show, but lots of people lose only modest amounts of weight or regain the pounds over time—a process known as “weight cycling” that is itself linked to cardiovascular and metabolic health problems.

For years, doctors had relatively few options to offer the many patients for whom diet and exercise didn’t work—things like the type 2 diabetes drug metformin, which can cause a modest amount of weight loss, and bariatric surgery, which works well but is unpopular among patients. And then came Ozempic and the rest.

Ozempic, Wegovy, and Mounjaro all work by simultaneously slowing digestion and mimicking the appetite-suppressing hormone GLP-1 through a weekly injection. (Mounjaro also targets a second type of hormone receptor.) This double whammy means people need to eat far less food than usual, leading to an average 15% to 20% reduction in body weight after about a year. They don’t work well for everyone, but compared to older meds, “the efficacy of these drugs is remarkable,” Takkouche says. “The weight loss is undeniable.” And this class of drugs doesn’t just lower the readings on a scale. According to data from Novo Nordisk, semaglutide (the generic name for both Ozempic and Wegovy) slashes the risk for major cardiovascular events like heart attack and stroke by 20% among overweight or obese adults with heart disease.

Justin, who asked to use only his first name to protect his privacy, saw “life-changing” results when he began taking Wegovy earlier this year. After struggling to lose weight through diet and exercise, the 29-year-old from North Carolina lost about 30 pounds in less than six months on the medication. As he followed instructions and scaled up his dosage over time, though, Justin started to experience side effects including acid reflux, nausea, diarrhea, and lethargy. (Research suggests intestinal blockage and an elevated risk of thyroid tumors are also potential side effects.) Eventually, Justin felt he had to choose between his health and his quality of life. As much as it pained him, quality of life won out.

Since quitting Wegovy in June, Justin has gained back about half the weight he lost, a common outcome for patients who stop using GLP-1 drugs—which many do, either because of side effects or cost, since many insurance plans don’t cover weight-loss drugs and out-of-pocket prices can exceed $1,000 a month. Despite his mixed experience, Justin would still recommend that someone trying to lose weight consider Wegovy, and may someday go back on it himself at a lower dose. “It made enough of a difference, and it’s something I’ve been wanting for so long” that it’s tempting to go back, he says.

Many obesity-medicine specialists share Justin’s feelings. “We have effective tools” for weight loss now, says Dr. Laura Davisson, director of medical weight management at West Virginia University Medicine. “Why not use them?”

There is one big reason, according to a passionate group of doctors, researchers, and activists who believe in the principles of Health at Every Size. They feel obesity never should have been labeled a disease in the first place—and thus may not need to be treated at all. “Manipulating weight is not a path to health,” says Ragen Chastain, a certified patient advocate who co-authored a library of Health at Every Size resources. “The belief that fewer fat people existing is good—that’s weight stigma.”

As Chastain and others like her see it, Ozempic and its sister drugs are not life-saving anti-obesity medications, but new tools for reinforcing old, damaging body standards rooted in stigma, not science—all while raking in gobs of money for pharmaceutical companies.

The idea that obesity is not a disease is still a controversial take in mainstream medicine. The CDC and American Medical Association (AMA) disagree with it, as do many physicians in the field.

“‘Healthy at any size’—I don’t even like the connotation,” says Dr. Caroline Apovian, co-director of the Center for Weight Management and Wellness at Boston’s Brigham and Women’s Hospital. “There is unhealthy body weight.”

And yet, the research on weight and health leaves room for questions. There are plenty of studies that show links between obesity and health problems ranging from fatty liver and sleep apnea to heart disease and cancer. But studies also suggest that up to half of people with obesity are metabolically healthy, that people in that camp are not at elevated risk for heart disease and death, and that people who are overweight may in fact have a lower risk of premature death than people at “normal” weight. Studies have also found that, even though obesity is considered a risk factor for developing heart disease, overweight patients tend to fare better than thinner patients when they’re treated for related conditions, a finding often called the “obesity paradox.” Research also suggests weight loss has less of an impact on health than physical fitness or the quality of one’s diet.

“We’ve got this entire body of research based on a hypothesis that if you make fat people look like thin people they’ll have the same health outcomes,” Chastain says. But she’s not convinced that’s the case at all.

For one thing, body mass index (BMI), the measure commonly used to diagnose overweight and obesity, is inherently flawed—a fact acknowledged by influential organizations including the AMA. When the AMA designated obesity a disease in 2013, its own Council on Science and Public Health urged against that decision. The council’s chief concern was the imprecision of BMI, which is a crude measure of total weight relative to height that, on its own, does not say much at all about someone’s health. It cannot, for example, distinguish between fat and muscle—which is why some athletes have BMIs that technically put them in the obese range.

BMI’s path to ubiquity is convoluted. The formula—weight in kilograms divided by height in meters, squared—was developed in the 1830s by Adolphe Quetelet, a Belgian mathematician interested not in diagnosing obesity, but in defining the “average man,” an effort that mostly glossed over people other than white men. The resulting formula, known as the Quetelet Index, fit neatly into the burgeoning field of “race science,” a pseudoscientific effort to draw distinctions between people of different races that fed into the eugenics movement, explains scholar Sabrina Strings, author of Fearing the Black Body: The Racial Origins of Fat Phobia.

By the early 1900s, prominent U.S. eugenicists had latched onto the idea that fatness was a marker of moral failing associated with people of color. “We think that fatness is linked to disease,” Strings says, but “the history of fat stigma actually transits through race science and eugenics.”

Later, in the 1960s, Black women were integral in starting fat-liberation movements that laid the groundwork for the modern body-positivity movement. These activists ran counter to the mainstream medical community, which was growing increasingly concerned about weight. In the 1970s, more than a century after the Quetelet Index was first developed, the prominent American physiologist Ancel Keys revived it. Keys felt insurance companies were using flawed methods of assessing weight-related health risks among people they covered. He proposed using the Quetelet Index (renamed as BMI) instead—even though, in a study he co-authored in 1972, Keys did not demonstrate that BMI consistently correlated with future heart disease risk.

Today, experts widely agree that BMI is imperfect. And yet, it’s still used in research, to diagnose obesity, and to determine who is eligible for drugs like Wegovy. “We’re knowingly saying, ‘We don’t even know how to measure [excess fat], but we’re going to use the measure we have anyway and define two-thirds of the population as diseased,’” says Dr. Lisa Erlanger, a Seattle-based family-medicine physician who supports Health at Every Size.

Erlanger believes that weight functions less as a measure of health than as a social determinant of health—in other words, a non-medical factor that nonetheless affects health through its impact on overall wellness. The weight stigma larger people encounter in doctor’s offices, the workplace, and social settings can all harm health, Erlanger says. And in the U.S., adults with obesity are likely to be non-white and non-college-educated, two socioeconomic factors also linked to poorer health outcomes due to structural inequality.

Erlanger feels so strongly that she has stripped weight from her medical practice wherever possible. Her office is designed to be comfortably navigated by people who are larger. The reading material in the waiting room doesn’t mention diets or weight loss. She doesn’t weigh patients at the beginning of their appointments. She never prescribes weight loss, and especially not weight-loss drugs.

“I support anyone’s efforts to reduce their marginalization in society,” she says. But, at the same time, “I believe I have an ethical obligation not to offer a treatment with false promises.”

It wasn’t weight loss that motivated Irene, who is 54 and lives in Washington State, to ask for a semaglutide prescription. Irene—who asked to use only her first name to preserve her privacy—has binge-eating disorder and often stayed up late into the night, snacking for hours after her husband and children had gone to bed. Irene read on social media that semaglutide had helped other people manage their binge-eating disorder, so it seemed worth a try. But it also felt something like self-betrayal.

For most of her life, Irene was locked in a cycle of losing and regaining weight, obsessing about food and calories and constantly wishing her body looked different. Then, a few years ago, she learned about Health at Every Size and threw herself into the community with gusto. She sought out doctors who shared her perspective and joined a fat-liberation group—which made her deeply hesitant about using semaglutide, a drug infamous for helping already-skinny Hollywood starlets slim down. “It has been tricky to lose some weight and not get caught up in that as an aspiration going forward,” Irene says. “I deeply, deeply believe in [Heath at Every Size] and would love for the rest of the world to come around to it as well.”

But now, she has to balance her support for the movement with the reality that, in an effort to manage her eating disorder, she has become one of the millions of people driving demand for anti-obesity medications to new heights.

Pharmaceutical companies seem perfectly happy to meet that demand. Some industry watchers have predicted that Mounjaro will become one of the highest-selling drugs of all time, sending maker Eli Lilly’s share prices soaring by about 25%. Meanwhile, Ozempic and Wegovy helped Novo Nordisk reach a nearly $442 billion market capitalization as of late October—higher than the gross domestic product of its entire home country, Denmark.

It’s no surprise, then, that an army of new weight-loss medications are receiving or marching toward regulatory approval, some with results even more impressive than their predecessors. Data from Eli Lilly suggest tirzepatide, the active ingredient in both Mounjaro and Zepbound, can help people lose about a quarter of their body weight in less than two years. The pharma giant is, along with other companies, also exploring oral GLP-1 drugs, which would have an even lower barrier to entry than their injectable formulas. (Novo Nordisk’s Rybelsus is already available as a pill.) With so many options currently or soon to be available, it’s not so far-fetched to imagine a world when all anyone needs to lose weight is a prescription.

Davisson, the obesity specialist from West Virginia, says about 80% of her patients are already on some form of weight-loss drug. She feels anyone who is overweight or obese should consider some form of treatment, since they may develop complications over time even if they’re healthy at the moment. “Everyone is metabolically healthy,” she says, “until they’re not.”

But other physicians are struggling with their place in this new world. When Dr. Mara Gordon, a family physician in New Jersey, finished her medical training almost a decade ago, she didn’t question the idea that weight loss was a good thing. But the longer she practiced—and saw how her patients shut down when she urged them to drop a few pounds—and the more studies she read, the more she began to doubt whether weight loss should be an assumed goal. “I found, increasingly, that it was all downside,” she says.

Gordon minimized weight’s role in her practice, focusing instead on other markers of health—things like insulin resistance (which can predict diabetes risk), blood pressure, chronic pain, mental health, and quality of life. Today, though, more and more patients come into her office asking for Ozempic and Wegovy by name. Often, she says, patients who want to drop pounds are technically overweight but have little medical reason for taking a GLP-1 drug: normal cholesterol, good blood pressure, no diabetes or warning signs for it. On a purely medical basis, Gordon feels there’s no need to take out her prescription pad.

But when she looks at the whole picture, the decision becomes more complex. Her patients’ test results may not signal a problem, but they’re still desperate to lose weight—maybe so they have the energy and mobility to play with their kids, or to improve their body image, or simply fit into a world that prizes thinness. In those moments, Gordon has to set aside her personal feelings about Ozempic, and about weight loss writ large.

“If you’re facing hatred and fatphobia on a daily basis, if you can’t do the things you need to do because the chair at your office isn’t the correct size,” Ozempic may truly help, Gordon says. “I wish we lived in a less superficial society. But my job is to take care of the patient right in front of me.”

She often writes the prescription in the end.

Update, November 8

This story has been updated to reflect the Nov. 8 FDA approval of Eli Lilly's Zepbound.