Throughout the past year, inquiries have been flooding in from all directions—patients, family, peers, and even strangers on flights have all asked: Is Ozempic suitable for me? Or any of the other weight loss and diabetes medications that have recently captured global attention? As I embarked on creating my latest documentary about these drugs, it became evident that many individuals have contemplated using GLP-1 drugs, enticed by the prospect of more stable blood sugar levels, improved cardiovascular health, and notably, weight reduction.

Despite obesity now being one of the most prevalent conditions in developed nations, there remains significant debate surrounding its diagnosis and the precise causes. Some experts even question if it should be classified as a disease at all. These subjects formed the crux of a compelling conversation I had in Copenhagen this spring with Dr. Jens Juul Holst, a Danish scientist instrumental in uncovering the molecules revolutionizing the diabetes and weight loss industries.

You've likely heard of Wegovy, Mounjaro, Zepbound, and Ozempic. Some speculate that Holst may be a future Nobel laureate for his contributions, while others argue he has inadvertently fueled an exorbitantly costly industry to address an issue better tackled with diet and exercise. Holst, a vibrant, energetic, and fit 79-year-old, still cycles to work daily. He shared that the initial aim of an international research team was to identify a molecule that could potentially treat peptic ulcer disease, not diabetes or obesity.

Although it didn't pan out for ulcers, a series of fortunate discoveries revealed that targeting GLP-1 could significantly reduce blood sugar and body weight. Crucially, for many grappling with obesity, these molecules appeared effective when all else had failed. He realized he had stumbled upon something that could be a game-changer. When the initial versions of these drugs were approved two decades ago, it might surprise you to learn that there was little fanfare. Hardly anyone was aware of them during those early years. Part of the reason was the internal debate among pharmaceutical executives who were uncertain if people would be willing to inject themselves to lose weight—and yes, among scientists like Holst, there was uncertainty about what they were actually treating. Obesity: A standalone disease?

Undoubtedly, obesity is associated with a myriad of other health conditions, such as type 2 diabetes, certain cancers, cardiovascular diseases, and stroke, among others. However, this does not imply that the link is universal or that obesity is the sole cause. After all, there are numerous individuals with obesity who show no signs of heart disease or diabetes. Their blood pressure is within the normal range, they require no medication, and their blood tests and physical functions show no abnormalities.

Their only 'disease' is an elevated BMI—excess weight relative to their height. When I inquired with Karin Conde-Knape, the head of drug development at Novo Nordisk, the manufacturer of Ozempic and Wegovy, about this, she responded with a smile, "Yes, we refer to them as the 'happy obese.'" She expressed concern that "these patients are on a path to developing these other diseases." Conde-Knape suggested that obesity should still be considered a disease because it could inevitably lead to complications—even if it hasn't yet.

Currently, many leading medical organizations, including the American Medical Association and the World Health Organization, concur with her perspective, but it remains a highly divisive issue that has become increasingly critical with the advent of these drugs. A study published in The Lancet this week projects that by 2050, 43.1 million children and adolescents in the United States and 213 million adults will be overweight or obese.

Yet, at a time when we can measure the particle size of minuscule lipid molecules and genotype tumors, it's striking that we still rely on an antiquated method known as BMI to diagnose obesity. BMI, or body mass index, is calculated using a formula first employed nearly two centuries ago when mathematicians—not physicians—were attempting to determine the ideal weight for humans; more specifically, "the quantifiable characteristics of the average man." Only European men were included in the original calculations—excluding women and children. It wasn't until over a century later, in the 1950s, that insurance companies noticed an increase in claims from individuals who were obese. Prior to that, there was no recognized correlation between BMI and overall health. BMI does not differentiate between muscle and fat mass. That's why even the most fit, sculpted, and health-conscious person you know might still be classified as obese. Holst, along with others, proposed that a better measure of obesity might be the simple use of a tape measure to assess your waist-to-hip ratio, which can evaluate visceral fat, in addition to body mass index.

The debate over whether obesity should be deemed a disease, especially as measured by BMI, will likely persist. However, there is a consensus I found among nearly everyone I discussed the topic with: Much like depression and addiction are now described as diseases of the brain, scientists are increasingly suggesting the same about obesity—that for many individuals, being obese is not a matter of choice or a reflection of lack of willpower. And, interestingly, it may be this new class of medications that has truly reinforced this point. Here's why. The GLP-1 molecules are characterized as post-nutrient hormones, substances the human body releases after consuming food. Collectively, they stimulate your pancreas to produce more insulin, slow down the rate at which food moves into your intestines, and activate areas in the brain that induce feelings of fullness or satiety.

As a neuroscientist, I find this last aspect particularly intriguing. It turns out that some individuals never truly feel full, no matter how many calories they've consumed. Instead, they experience a constant, tormenting food chatter in their minds. Even as they're eating one meal, they're already contemplating the next one, never experiencing genuine satiety. This is part of the reason they continue to consume far more calories than necessary. For them, GLP-1 medications can literally silence those voices in their heads.

Holst is also very focused on this particular mechanism of the GLP-1 drugs but is concerned that it can go too far. Over a meal of coffee and delectable pastries, he shared that these drugs seem to diminish the pleasure of food for some individuals. It is perhaps his most significant concern. People stop socializing as frequently, knowing they won't be hungry for dinner. They may also become too thin too quickly, leading to associated sagging skin and fatigue.

For others, it's the loss of lean muscle mass that accompanies their weight loss and increases their risk of falls. Since the medications work by slowing digestion, severe constipation becomes a side effect that is too much for some to endure. Consider this: More than half of the people who start these medications end up discontinuing them within just 12 weeks. For some, the medications are too costly and eventually become financially unattainable. Others develop a tolerance to the drugs, and over time, they may cease to be effective. But for many, it is these side effects—including the loss of joy—that drive their dissatisfaction with the medications. And again, it was that loss of joy that was particularly concerning to Holst.

"It is a heavy price to pay," he told me. For now, the question keeps arising: Who should consider taking these drugs? Should I try these drugs? There is little doubt that for most individuals, regular exercise and a balanced diet remain the best strategy for weight loss and overall health. High-fiber diets, for instance, tend to release more natural GLP-1. Among those who took GLP-1 medications and discontinued them, those most likely to maintain their weight loss had integrated lifestyle changes in a meaningful way. Most people do regain weight after stopping the medications, but importantly, not all individuals and not all the weight.

For those able to keep the weight off, these medications weren't a lifelong solution, but rather a catalyst to help reverse their obesity trajectory. Yes, we have a lot of work to do in better defining and assessing obesity. That's what Holst really wanted me to understand after his decades of work on the subject. In the meantime, however, these medications might finally offer a lifeline for those who have truly struggled for far too long.