There is no shortage of conversation surrounding weight, particularly when it comes to obesity, when a person’s body mass index (BMI) creeps above 30.

Authoritative scientists and health organizations like the Centers for Disease Control and Prevention (CDC) continuously warn of an ongoing obesity crisis that threatens to swallow our waistlines and end our lives prematurely, while gossip rags and television shows laud the individuals that rise to the top and complete drastic weight loss attempts. Indeed, the collective fascination with weight even extends to health and news sites such as Medical Daily, with a seemingly neverending supply of new studies and well-worn tips guaranteed to help us keep off the pounds for good.

But amid the blaring clarion calls to combat obesity, lose weight, and achieve bodily bliss, there has been a growing — if loosely knit — contingent of activists, researchers, and academics who openly question weight’s role in society and medicine.

The earliest of these critics often belonged to the still-active fat acceptance and body positivity movements, which sought to fight back prejudice against the overweight as early as the 1960s. Later advocates include law professor Paul Campos, who called for the complete dismantling of obesity as a legitimate health problem in his 2004 book, The Obesity Myth. And in more recent years, organizations like the Association for Size Diversity and Health have not only seen themselves as “obesity skeptics” but as messengers of their own public health narrative, one largely framed by the Health at Every Size (HAES) approach formally launched by Dr. Linda Bacon, a nutritionist with expertise in psychology and exercise metabolism, in 2010.

It’s obvious that HAES has continued to endure in the public sphere, and Bacon’s third book on the subject is due out later this year under the title Eat Well: For Your Self, For the World. So Medical Daily decided to take a close — and hopefully fair — look at some of the basic premises behind the arguments Bacon and other HAES proponents make, and to see where they lead us.

Health At Every Size

Like its forebearers, HAES has directly attacked commonly held ideas about obesity and weight. Some of these include:

  • Being fat is a significant health risk, and cuts life expectancy.

  • Losing weight noticeably prolongs our lives, with an effect similar to quitting smoking.

  • Anyone who is determined enough can sustain long-term weight loss through diet and exercise.

  • Weight loss is a positive public health and individual goal to shoot for.

"So much of the public perception — even among scientists — depends on an a priori belief that higher weight is bad," Dr. Deb Burgard, a California psychologist and longtime stalwart of the HAES movement, told Medical Daily. "But assigning a moral judgement to people's bodies is itself bad for people's health."

Ultimately, advocates feel the fixation on weight has had disastrous effects on the public, leading to an increased prevalence of weight discrimination, eating disorders, and internalized stigma.

But HAES practitioners also have their own strategy for health maintenance. “The idea is to separate issues of health from weight,” Harriet Brown, a journalist and HAES supporter who has herself argued against the popular perception of weight in her 2015 book Body of Truth, told Medical Daily. “Intentional weight loss for 90-plus percent of people is associated with worse health outcomes, so HAES looks at health-positive behaviors — for instance, developing a physical activity routine that’s sustainable and enjoyable.”

These behaviors might indeed lead to weight loss, but that’s irrelevant to the pursuit of health itself, she added. Equally important to the HAES approach is establishing a sense of acceptance and appreciation of one’s current body and fostering healthy eating patterns that rely less on calorie counts and more on internal hunger cues.

As for the claims listed above, the evidence for or against them is crystal clear in some cases and muddled elsewhere.

For example, while the exact figure varies, it’s absolutely true that the vast majority of people who attempt weight loss through nonsurgical means do not succeed long-term. Sure, some might lose a good amount of weight, but most regain it and often add more back on within a year. Bariatric surgery can offer more dramatic and sustained weight loss, but it comes with real health risks, is only recommended for people with severe obesity, and requires lifetime maintenance. Even there, people do regain some of their weight.

“Weight loss approaches that are marketed in the mainstream media and that most people are familiar with don’t work, and research scientists have known this for thirty years,” Dr. Charlotte Markey, the director of Health Sciences at Rutgers University and author of the 2014 book Smart People Don’t Diet, told Medical Daily. Markey’s book, while emphasizing that reality, attempts to guide the reader through some of the concrete weight loss tips we have learned, such as getting enough sleep, adjusting our diets slowly and indefinitely, and avoiding sugar whenever possible. “The public is happy to spend money on diet plans and pills and books that are not empirically based, because people want a quick fix; people want to lose weight fast and forever, and they don’t want to do any work associated with that.”

These failures can’t simply be chalked up to a weak-willed or lazy populace though. Losing weight isn’t really the hard part; it’s the fact that our bodies biochemically rebel against the act by lowering our metabolism and raising our appetite, sometimes permanently. And let’s not ignore the various environmental obstacles that coax and sustain excess weight. “It does not make sense to encourage people to eat less while marketing to them food engineered to make them eat more,” Dr. David Katz, founding director of the Prevention Research Center at Yale University, told Medical Daily. “ There is one word for that: hypocrisy.”

Likewise, it’s becoming apparent that the link between health and excess weight isn’t as strong as we might think. Some research has shown that factors like our level of sleep, sedentary behavior, and fitness are much more relevant predictors of health and chronic disease than being overweight or mildly obese: A fit person may have roughly the same buffer against an early grave regardless of their BMI. Similarly, not sleeping enough or sitting too much are problems common to everyone, regardless of how much they weigh, and weight loss won’t fix them. Other research has repeatedly shown that obesity has a protective effect for certain populations, such as the elderly and those with heart disease.

Long under scrutiny from activists, BMI has increasingly gotten the cold shoulder from scientists as well, with studies demonstrating it's relatively poor at assessing chronic disease risk in both directions: It can lead doctors to think that otherwise healthy overweight and obese people are unwell, and to give a clean bill of health to skinny individuals who actually need more follow-up. That kind of mix-up might result in as many as 20 percent of patients being placed at the wrong level of cardiovascular disease risk, cardiologist Dr. Brent Muhlestein has told Medical Daily.

A Divide

In reaching out to researchers and clinicians on obesity and nutrition unaffiliated with HAES like Katz, I found wide agreement for most of the HAES talking points. But there are aspects of the movement that they have concerns about.

“The HAES movement is, at its origins, about fairness and equity, and about not judging books by their covers, or people by their weight. I support all of that; scales do not measure human worth. I fully endorse the push back against obesity bias in our society,” Katz said. “But the simple fact is that excess body fat is a risk factor for most major chronic diseases — it just is. So if weight is an indicator of health risk, it must be treated as such.”

Those like Katz worry that HAES proponents sometimes smudge the distinction between weight not being the most important measure of health and weight not being relevant at all to health. It’s a criticism that’s not entirely off the mark.

One of Bacon’s arguments against tying excess weight to premature death is that both life expectancy and average BMI have risen over the past 30 years. While true, this ignores the role that reduced infant mortality, increased health care access, and just plain better health care play as primary drivers of longer lifespans. None of these factors exclude the possibility that excess weight can be harmful.

And while it’s certainly correct that the associations between excess weight and conditions like type 2 diabetes, arthritis, and sleep apnea do sharply lessen once you account for other factors like fitness, they don’t disappear entirely, and the connection becomes stronger the more obese someone is. In response to this point, Brown noted that relatively few people wind up in the most dangerous category of obesity: class III. As of 2010, 6.6 percent of Americans fell into this group, according to one study, but that number is likely rising. While obesity levels in general had previously been stable since the mid-2000s, the latest CDC data indicates that rates are once again ticking up, and they are the highest yet, with nearly 38 percent of all adults over the age of 20 obese as of 2014. There’s also some limited evidence that too much weight in our earliest years may be more damaging than becoming obese later on.

Burgard correctly notes that there are no health problems that only happen to higher-weight people, and there is no weight that will magically protect you from getting sick or dying; weight is only one of many considerations we should keep in mind when trying to stay well. Crucially, though, even if overweight and mild obesity weren’t risk factors at all for poorer health, it would still be a public health concern that Americans are getting fatter over time. That’s largely because, as the average BMI in a population increases, so does the number of people who end up at the more extreme levels of obesity, similar to how the higher a country’s average alcohol consumption is, the more citizens become problem drinkers.

While rightfully taking down our mistaken presumptions about weight, there’s the danger that some HAES proponents are also downplaying the few facts we do have a grasp on. “We should be careful not to minimize these health issues [related to obesity] — while at the same time not stigmatizing those affected by obesity,” Dr. Louisa Baur, a professor of pediatrics and child health at the University of Sydney in Australia, told Medical Daily.

The Way Forward

Not everyone makes such level criticisms of HAES. Commentator Cathy Young has argued that “the fat acceptance movement is hazardous to our health;” others claim that HAES is actively encouraging people to stay unhealthy.

There are studies showing the HAES approach and its concepts do just the opposite: allow people of all sizes to adopt lifestyle behaviors that subsequently improve both their physical and mental health. “Few if any of these conversations about health and weight consider psychological health,” Brown said. “Personally, I’d much rather live the way I do — eating well, exercising well, able to do pretty much everything I want, generally feeling good about myself, but still obese on the BMI chart — than devote huge amounts of mental real estate to being thin.”

As I’ve detailed in The Atlantic, there’s conflicting evidence that the experience of successful weight loss makes people any happier — even people who lose weight in a carefully controlled experiment tend to be happier because of their lifestyle changes and greater social support rather than the actual amount of weight they lost. Conversely, there’s plenty of evidence showing that weight discrimination is rampant, even by medical professionals, and actively harms people, oftentimes by leading them down a path of constant weight cycling that may only worsen their overall health.

And while Brown is willing to concede that obesity may be a public health issue despite her reservations about much of the research (a healthy skepticism, it seems), she has a strong rebuttal. “The big problem I have with all this — and the reason I remain an advocate of HAES — is that pretty much everything we have done in the last 50 years that’s aimed at making people thinner has made them fatter and less healthy and likely exacerbated the processes that have made us heavier in the first place,” she said. “So even if you truly believe that obesity is a problem, why would you keep approaching it in the very same destructive and ultimately counterproductive ways?”

A sparkling example of that destruction can be seen in the recent trend of schools sending so-called “BMI report cards” to the homes and parents of their students. While the practice, now prevalent in 10 states according to The New York Times, ostensibly allows families to head off the possibility of childhood obesity, there’s evidence indicating it’s done literally nothing to improve any health outcomes, and some say that it’s only contributed to the development of eating disorders in our youngest.

The idea that our current thinking about weight and obesity is drastically wrong received universal endorsement from everyone I spoke to. “This is not about lapses in individual willpower — it's about a species wrestling with modern challenges for which it has no native adaptations,” Katz said. “We are still figuring it out, and clearly have a ways to go.”

Answering these challenges will not only require sweeping changes to our environment, but to our collective psyche as well. Encouraging our society to stop using weight as an excuse to stigmatize and isolate people who fail to meet our misperceived ideals of health is surely one of those changes, one that the HAES movement appears prepared to fight for.

"Most people who want to change their weight are actually trying to change the way they are treated," Burgard told me. "Our bodies are not the source of how we are treated — other people are."