Weight bias is not only insidious; it is often covert and/or dismissed. Prejudices about body weight are seldom recognized by the people who hold them, and so negative stereotypes persist, say researchers at the University of Connecticut Rudd Center for Food Policy and Health.
These stereotypes include assumptions that people with obesity are lazy and undisciplined, or that obesity is a choice and weight is something people can change, if they want to, by simply eating less and exercising more. Some people may even wrongly believe that stigmatizing a person for their weight may motivate them to lose it. This is hogwash.
As with any complex disease, however, the causes of obesity, and the challenges of living with it, are commonly misunderstood and misconstrued. Here are 10 pervasive myths and bias-busting truths about body weight to set the record straight.
1 of 10
Myth: Obesity is not a disease.
Truth: The World Health Organization (WHO) classifies obesity as a chronic, relapsing disease arising from complex interactions between genetics, neurobiology, eating behaviors, access to a healthy diet, market forces, and the broader environment. The WHO refers to obesity as a global public health crisis. It says more than 1 billion people are living with obesity and prevalence is rising in nearly every country.
Similarly, the American Medical Association (AMA) has officially classified obesity as a disease, defining it as chronic and complex, with multiple pathophysiological factors, and often assessed via body mass index (BMI) measurements with 30 kg/m² or more signaling an obesity diagnosis.
2 of 10
Myth: High body weight is always unhealthy.
Truth: Though research links obesity to type 2 diabetes, heart disease, sleep apnea, and certain kinds of cancer, weight is not an indicator of health, in and of itself. In fact, individuals with a high body weight can be metabolically healthy. They may have good nutritional and behavioral habits, while individuals with low body weight may have high blood pressure and cholesterol, and bad nutritional and behavioral habits (eating highly processed foods and avoiding exercise, for instance).
3 of 10
Myth: Obesity is a “lifestyle choice.”
Truth: Weight stereotypes assume that individuals with obesity have made bad decisions about food and exercise. But blaming this disease on a person’s lifestyle choices and character is not only misguided — it’s dangerous. Why? Because “how we define obesity matters,” say the authors of a 2025 Lancet Global Health report. “Definitions shape whether health systems track obesity prevalence, allocate funding to address it, and include prevention and care in essential benefit packages and primary care services.” The “lifestyle choice” narrative, the authors conclude, reinforces stigma and sustains policy inertia.
4 of 10
Myth: Weight stigma can motivate people with obesity to lose weight.
Truth: Body shaming makes people with obesity feel worse about themselves, but research shows it does not motivate them to lose weight. In fact, the opposite is often true. Studies show that the stress associated with weight bias may actually cause people to gain weight. That’s because stress can lead to unhealthy physical reactions and coping behaviors, such as binge eating. Sadly, people who experience weight bias are also at a higher risk of depression, anxiety, and even self-harm.
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Myth: Obesity rates are high only in the U.S.
Truth: The U.S. has the highest adult obesity rate in the world (more than 40%). However, obesity rates are climbing steadily across the globe, with adult obesity rates more than doubling and adolescent obesity quadrupling since 1990. It is projected that more than half the world’s population will soon be living with overweight or obesity.
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Myth: It’s possible to lose weight (and keep it off) through diet and exercise alone.
Truth: Human biology makes it easy to gain weight but much harder to lose it. One study by former National Institutes of Health (NIH) researcher Kevin D. Hall, PhD, shows that most individuals who lose weight through diet and exercise regain half of it within two years, and 80% of it within five years. The upshot? Significant weight loss maintenance is very challenging for many biological and well-established reasons.
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Myth: Doctors and nurses are immune to weight bias.
Truth: Weight bias is pervasive, even in health care settings. In fact, one systemic study found that weight bias toward people living with overweight and obesity existed not just among doctors and nurses, but also among dietitians, psychologists, physiotherapists, occupational therapists, speech pathologists, podiatrists, and exercise physiologists. According to the Obesity Action Coalition, doctors are a common source of stigma, with some reporting less desire to help patients with overweight.
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Myth: Weight bias doesn’t count as discrimination.
Truth: In the U.S., no federal laws prohibit weight discrimination in the workplace, which makes weight bias one of the last socially acceptable prejudices in our society. That means workers who are discriminated against by employers because of their weight have few options for legal recourse.
Michigan is the only state with a law explicitly prohibiting weight-based discrimination. Other states, like Massachusetts, are trying to put one in place. Some states, like Washington, offer disability protections to people with obesity under their anti-discrimination laws, but most do not. In Texas, for example, obesity is disqualified as a disability if it can be attributed to “lifestyle choices.”
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Myth: Fat jokes are harmless.
Truth: A fat joke is akin to a racist joke, say researchers at the University of Connecticut’s Rudd Center. Even making a comment “in good fun” may condone weight bias, they say, and perpetuate negative stereotypes that can lead to bad outcomes for people who suffer mental health harms after years of these insidious jokes.
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Myth: The food industry is not to blame for obesity.
Truth: The causes of our obesity epidemic are varied and complicated. But changes to our food environment and overall eating behaviors definitely play a part. “Disentangling the relative contributions of these environmental variables is a difficult problem,” Hall says, “but it seems clear that the food environment is likely the primary driver of the obesity epidemic.”
