Unpacking What You Know About Fat People
Author and podcast host Aubrey Gordon debunks stereotypes and discusses anti-fat bias in healthcare.
The following is an excerpt from “You Just Need To Lose Weight” And 19 Other Myths About Fat People by Aubrey Gordon.
Disclaimer: When you purchase products through the Bookshop.org link on this page, Science Friday may earn a small commission which helps support our journalism.
"You Just Need To Lose Weight" And 19 Other Myths About Fat People
“Have you ever tried losing weight? It’s not that hard.”
I was nineteen, attending my first college party. I was acutely aware of my fatness, my queerness, my then-profound social anxiety, differences that felt like they stuck out like a sore thumb among my peers. I hadn’t wanted to go to the party (I’ve never loved parties), but it felt like an important experience. I spoke sternly to myself, insisting that the party was important to some nebulous college experience, that I’d thank myself later. So I went. My first conversation was with this stranger, a man whose opening salvo was to ask me to account for my body. How had I gotten so fat, he wondered aloud, and why wasn’t I thin?
“You should try—it’s really not that complicated. It’s not like diets are rocket science. It’s just calories in, calories out.”
I assured him that I’d lost weight in the past but had ultimately regained more weight after my diet. He responded with a lengthy lecture about calories, fat, and carbohydrates. “Just look at the science. It’s pretty clear.”
I stumbled through more clumsy responses, reaching for an acceptable explanation for why I was so inexcusably fat. He wanted me to account for my size, and it had never occurred to me that I didn’t owe a detailed history of my body to anyone who asked. Friends, family, acquaintances, and strangers alike expected answers about why I was so fat. I learned that being fat meant providing explanations of my size to thin people who would then explain to me why I was wrong and how I could look more like them. This stranger at the party was no different. Like so many before him, no explanation of my body satisfied him. He only relented when I reassured him, three times, that I was still trying to lose weight. When his interrogation ended, he left to find a cigarette and another beer. I left the party.
Even at such a young age, I had become accustomed to cold, incurious responses like his, nearly always delivered by people thinner than me. All of them presumed that my body was a failure, universally undesired because it was inherently undesirable. They assumed that my body was inferior to theirs, and they inferred that was because my character and work ethic were inferior too. And they insisted that, as thin people, they were experts on weight loss—even if they’d always been thin. Even if they’d never lost as much weight as the one, two, or three hundred pounds they expected fatter people to shed as soon as possible. If they were some of the rare few that had sustained major weight loss, they were more likely to be relentless, insistent, inescapable. I did it. Why can’t you?
Most of us have been told that weight loss is a direct reflection of our effort: if we try hard enough, we’ll lose weight. But the science of weight loss paints a much more complicated picture.
One of the most important components of any weight-loss attempt, we’re told, is willpower. Yet the science around diet and willpower doesn’t bear that out. Much of what we think of as insufficient willpower in dieting is a biological response to food restriction. Hormones like ghrelin and leptin are powerful regulators of our health and satiety. Ghrelin, the so-called hunger hormone, creates a powerful drive to consume the nutrients our bodies need to survive. A 2011 study of fat adults found that those who lost weight had higher levels of ghrelin for at least one year after weight loss. Rather than a lack of willpower, dieters had gone through a physiological change that increased their biological drive to eat.
Leptin, nicknamed the “satiety hormone,” tells us when to stop eating. Higher body weights have been linked to leptin resistance, a condition in which patients have high levels of leptin circulating, but their bodies don’t respond to it. It seems that leptin plays a role in weight regulation and that leptin is produced by fat cells, but researchers do not know precisely how leptin works, nor why some patients are leptin resistant and others aren’t. Ghrelin and leptin are just two of fifteen hormones that are believed to help shape our appetites. Dopamine, serotonin, and insulin have all been shown to influence hunger, satiety, and desire for food. Research indicates that our endocrine systems, not our will- power, are significant mechanisms that determine, in part, when and whether we feel the drive to eat. Our bodies have also been shown to drop their energy usage by about two hundred calories per day when we restrict calorie intake. According to researchers, our body weights are “tightly regulated by hormonal, metabolic, and neural factors,” factors that “appear to defend an individual’s highest sustained body weight.” That is, regardless of our willpower, when we lose weight, our bodies seem geared toward returning us to our highest weight.
Exercise is frequently pointed to as a key factor in weight loss. But research has long since debunked the myth that exercise is a primary driver of weight loss. A 2001 research review on exercise studies found that in the short term (sixteen weeks or less), exercise led to three times more weight loss than in the long term (twenty-six weeks or more). While that may sound like a ringing endorsement of short-term exercise programs for weight loss, the raw numbers are significantly less impressive. Intensive short-term exercise programs of under four months yielded a loss of 0.18 kilograms, or 0.4 pounds. Longer term programs led to a weight loss of one-third that—0.06 kilograms, or 0.14 pounds. That echoed a 1999 research review, which found similarly underwhelming results.8 A later review in the Cochrane Database of Systemic Reviews looked at 43 studies in which 3,476 participants with “overweight” and “obese” BMIs participated in exercise programs lasting between three and twelve months. The review’s narrative trumpeted the success of exercise as an intervention for weight loss, but even fat participants who took on high intensity workouts for up to a year found only modest weight loss (1.5 kilo- grams, or 3.3 pounds). For me, as a 340-pound person, those 3.3 pounds would represent a less than 1 percent reduction in my body weight—a far cry from making me thin. Exercise can, however, reduce risk factors for heart disease, support cognition, and provide a wide range of other health benefits. Physical movement can offer a lot—it just doesn’t lead to significant weight loss. And exercise isn’t accessible to everyone: Many are too busy working multiple jobs or raising children to fit in an exercise regime. Others may live in inaccessible neighborhoods that make outdoor activity difficult, with a lack of sidewalks, parks, and disability accessible infrastructure. For still others, exercise may bring with it painful memories of being bullied or feeling judged in gym class or by loved ones who pushed them into weight loss. Exercise is fraught territory for many of us, and promoting exercise without accounting for whom it might be inaccessible is simply exclusionary.
Some say that weight loss is a simple matter of finding the right diet for you—the one that works, that you can sustain. But time and time again, research shows that diets and “lifestyle changes” don’t result in lasting weight loss. As Harvard University’s Robert H. Shmerling put it, “You can’t pick the right diet if none of them work.” Shmerling was referencing a 2020 research review published in the British Medical Journal, which represents one of the largest research reviews yet of popular weight-loss diets, digging into 121 randomized trials that included 21,942 participants with “over- weight” or “obese” BMIs. Researchers looked into fourteen popular diets: Atkins, South Beach, the Zone, the Biggest Loser, DASH, Jenny Craig, the Mediterranean diet, Portfolio, Slimming World, Volumetrics, Weight Watchers, the Ornish diet, and the Rosemary Conley diet. Low-carbohydrate and low-fat diets had similar results, each leading to a weight loss of about 10 pounds (or 4.5 kilograms) in fat people—and that weight loss diminished after a year in every diet studied. Essentially, multiple diets provided short-term weight loss, but all stopped working by the twelve-month mark. Additionally, “the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared.” Thirteen years earlier, UCLA researchers published similar results in a thirty- one-study research review in American Psychologist, finding that “you can initially lose 5 to 10 percent of your weight on any number of diets, but then the weight comes back.” Indeed, research has shown short-term weight loss leads to long-term weight gain. A clinical trial with 854 subjects found that, after weight loss, only a sliver of study participants maintained a lower weight. “More than half (53.7%) of the participants in the study gained weight within the first twelve months, only one in four (24.5%) successfully avoided weight gain over three years, and less than one in twenty (4.6%) lost and maintained weight successfully.” And longitudinal studies of twins have found that a greater number of attempts at intentional weight loss “predicted accelerated weight gain” and that frequent attempts “render dieters prone to future weight gain.” Whether we call it a diet, a detox, a cleanse, or a lifestyle change, intentional weight loss frequently produces long-term weight gain.
Popular weight-loss interventions largely fall into three camps: low-carbohydrate, low-fat, and low-calorie diets. A closer look at all three provides similarly lackluster results. Not only do low- carbohydrate and low-fat diets both produce underwhelming weight loss, each also presents unique possible health risks. Low-carbohydrate diets like Atkins, keto, paleo, and South Beach have seen a surge in popularity over the last twenty years. But a 2019 study linked carb-restricted diets to significant increases in mortality, including a 51 percent increase in mortality from coronary heart disease. While mortality rates can be difficult to determine definitively, this study had some advantages. First, it combined its research with a meta-analysis of existing studies. Second, it used a large, existing, nationally representative data set of 24,825 participants. And third, instead of attempting to predict mortality, researchers looked at actual mortality. The results seemed to indicate that low- carbohydrate diets were far from risk-free. As one of the study’s authors told one reporter:
Low-carbohydrate diets might be useful in the short-term to lose weight, lower blood pressure and improve blood glucose control, but our study suggests that in the long-term they are linked with an increased risk of death from any cause, and deaths due to cardiovascular disease, cerebrovascular disease, and cancer. [ . . . ] The findings suggest that low-carbohydrate diets are unsafe and should not be recommended.
Low-fat diets, like Weight Watchers and Ornish, saw their peak of popularity in the 1980s and 1990s. Those diets can be mislead- ing, says researcher Dierdre Tobias, “because a food’s fat content doesn’t do a lot to determine if it’s healthy or not.” As with any diet, hyperfocus on restriction of calories and macronutrients can lead us away from a wider range of foods with a wider range of nutrients. The most extensive studies into low-fat diets find only minor weight loss, and no impact on other health risks, like colon cancer, breast cancer, or cardiovascular disease. Fat and carbohydrates are themselves nutrients, and each is essential—carbohydrates are key for brain function, and fat is essential for metabolic processes. For those without specific health conditions and disabilities to manage, neither of these diets leads to significant, sustained weight loss, and neither is free of health risks.
But perhaps the most deceptive diet approach is a low-calorie diet focused on “calories in, calories out.” It sounds so simple: Take in less than you burn. Eat less, exercise more. But countless people count calories every day, and only a sliver of us lose weight in the long term. So why do we keep repeating it?
“Calories in, calories out” dates back to a 1959 paper published in the American Journal of Clinical Nutrition.
Its author, Max Wishnofsky, laid out an analysis of existing literature on weight loss and concluded that each pound lost or gained had a “caloric equivalent” of 3,500 calories. Years later, an influential medical textbook, Modern Nutrition in Health and Disease, echoed Wishnofsky’s work, writing that losing one pound would require “an energy deficit of approximately 3,500 kcal.” That concept—that each pound lost was a matter of simple arithmetic, cutting 3,500 calories from one’s diet— was repeated widely in medical literature and popular media alike. Researchers’ understanding of metabolism and the human body’s composition has progressed significantly since 1958, and many of the assumptions that led to Wishnofsky’s rule have since been disproven. He also drew from the evidence available at the time—short-term studies with small sample sizes. But the body of evidence surrounding weight and weight loss has grown by leaps and bounds since then.
By today’s standards, Wishnofsky’s evidence wouldn’t be considered strong. Plus, researchers have since found a wide range of influences on our ability to lose weight, from hormonal influences to genetic markers—none of which are captured in such a simple equation. In 2015, a paper in the Journal of the Academy of Nutrition and Dietetics compiled all of the ways in which Wishnofsky’s work fell short, became outdated, or was inaccurate. Its authors concluded that his rule is easy to use but “lacks a contemporary scientific foundation and leads to a large error in weight-loss prediction, even over the short term.” They further argued that newer models of weight-loss prediction couldn’t yet be established as definitive, and that even the best population-level models won’t capture individual biological differences. Models like these, then, cannot be used to predict any individual’s weight loss or gain.
Over sixty years of new evidence shows that, at the population or individual levels, we certainly cannot claim that weight loss is as simple as “calories in, calories out.” Despite clear, consistent evidence that our body weights are a result of much more complex processes than just calorie-counting, we continue to center calorie restriction in weight loss and public health. We mandate calorie labeling on menus, despite evidence that they increase awareness of calorie counts, but don’t change the number of calories we order in restaurants. We rely on nutrition labels on packaged food as guidance, presuming that 2,000 calories per day is the correct amount for our health and for maintaining weight. Most of us don’t know that the US Food and Drug Administration (FDA) designed nutrition labels primarily as popular education tools. Their 2,000-calorie recommended daily allowance didn’t come from nutritional or medical best practices. It didn’t have any scientific basis at all. Instead, the FDA based its recommendation on Americans’ self-reported calorie intakes, which ranged primarily between 1,600 and 3,000 calories per day.26 They initially proposed a recommendation of 2,350 calories per day but, amid fears that it would encourage overeating, rounded down to an easier-to-use number of 2,000 calories per day.
Calorie counts and labels, it seems, have always been shaped by social anxieties about fatness. And while those labels do reflect the number of calories in a particular food, they don’t reflect their caloric availability: the number of calories our bodies can actually metabolize from those foods. University of Cambridge researcher Giles Yeo asserts that understanding caloric availability is central to understanding the science of weight and metabolism. “Caloric availability is the amount of calories that can actually be extracted during the process of digestion and metabolism, as opposed to the number of calories that are locked up in the food.” That is, while a food may have one hundred calories in it, our bodies may be able to digest only a portion of those.
Accordingly, Yeo argues, every calorie count on every nutrition label and restaurant menu is, at worst, false and, at best, misleading.
Ultimately, there’s a lot we don’t yet know for certain. We don’t know precisely why some people are fat and others are thin. We don’t know why weight loss is so limited in the short term, or why the vast majority of those who lose weight cannot maintain that weight loss for more than a year or two. The worlds of nutrition and weight loss are full of unanswered questions. Nearly all avail- able weight-loss interventions are ineffective for most people, most of the time. But each drives toward a proudly exclusionary vision of a world without fat people. And each presumes that fat bodies are broken and must be fixed.
Often, that impulse to “fix” fat bodies is referred to using a particularly pernicious euphemism: “getting healthy.” “Losing weight” conjures the uphill battle and low success rates of outdated diets. For those of us with mothers who dieted, “losing weight” calls up their endless, futile struggles at once to change their bodies and make peace with them. “Getting healthy” is aspirational, optimistic, laudable. It seems to eschew size, instead prioritizing health, but quietly, implicitly links the two. Referring to weight loss as “getting healthy” reveals so much about our assumptions and values around health, size, chronic illness, and disability.
For years, “getting healthy” has paved the way for conflating fatness with ill health, assuming that anything that delivers thinness is healthy and anything healthy will lead to thinness. But paradoxically, many of us pursue weight-loss methods that put our health at risk.
Crash diets and low-calorie diets of less than 1,200 calories per day can cause loss of muscle mass. Popular appetite-suppressant lollipops and teas have a laxative effect that can lead to dehydration and, if used for more than two weeks, can cause dependence on laxatives. Immensely popular low-carbohydrate diets like Atkins and keto can lead to weight loss in the short term but may lead to an increase in all-cause mortality when followed in the long term. Even when we make seemingly less risky decisions to pursue weight loss, some health indicators may worsen. Weight loss brings a greater risk of gallstones, loss of muscle mass, liver dysfunction, digestive issues, and hair loss. Weight loss is also associated with weight cycling, or repeated loss and gain of weight. Those fluctuations can be caused by repeated attempts to lose weight, sometimes described as “yo- yo dieting.” Whatever its cause, a research review of twenty-three studies with over 440,000 participants linked weight cycling to an increased risk of cardiovascular disease, hypertension, and mortality from all causes. Some research indicates that dramatic weight loss may permanently suppress one’s metabolism. And according to Australia’s National Eating Disorders Collaboration, attempting intentional weight loss by restricting one’s diet “is one of the strongest predictors for the development of an eating disorder.”
But, of course, none of that eases the cultural pressure for fat people to lose weight because that pressure was never born of sup- port for fat people or our health. Too often, the stigma fat people face is thinly veiled by a purported “concern for our health,” a kind of well-intended bullying that ends up compounding the harms we face. But that “concern for our health” isn’t rooted in any hard- and-fast knowledge of our health. Overwhelmingly, those who offer unsolicited weight loss and health advice haven’t read our medical charts, participated in our health care, or learned the intimate details of our health history. They do not know the state of our health markers, nor will they ask after our blood pressure or mental health. Their concern is prompted solely by our appearance. To be fat, they believe, means to be unhealthy. And to be unhealthy shirks some perceived moral responsibility to deliver the appearance of health to those around us.
Excerpted from “You Just Need to Lose Weight”: And 19 Other Myths About Fat People by Aubrey Gordon (Beacon Press, 2023). Reprinted with permission from Beacon Press.