According to the Centers for Disease Control and Prevention (CDC), 42.4% of adults in the U.S. have obesity. On a global scale, the World Health Organization (WHO) estimates that roughly 650 million adults are living with obesity.
While awareness about the health risks linked to obesity is growing, persistent myths continue to spread despite public health efforts. Many of these misconceptions fuel stigma, which can harm the mental well-being of those affected.
For example, a 2020 meta-analysis found that the link between weight stigma and poor mental health grows stronger as body mass index (BMI) increases.
Debunking obesity myths is crucial, so this article will address five of the most common misunderstandings.
1. “Just eat less and move more” is all it takes to tackle obesity
In many cases, long-term calorie surplus is the direct cause of obesity, and most weight-loss strategies focus on cutting calories, boosting physical activity, or both.
However, while diet and exercise matter, other overlooked factors can also play a big role. These include poor sleep, stress, chronic pain, hormone disruptors, and certain medications. Sometimes, overeating is a symptom—not the root cause.
These factors can also interact, making obesity harder to manage. For instance, stress raises obesity risk, but obesity itself can be stressful due to stigma, creating a vicious cycle. Stress also disrupts sleep, and poor sleep is another obesity trigger. Research even shows that stress hormones rise when sleep declines.
Sleep apnea—pauses in breathing during sleep—is more common in people with obesity. Weight gain can worsen sleep apnea, leading to sleep loss, which may then drive further weight gain.
Chronic pain is another factor tied to obesity, likely due to a mix of chemical, emotional, and lifestyle influences. Pain can heighten stress and disrupt sleep, adding to the cycle.
Stress, sleep, and pain are just a few interconnected factors. While “eat less, move more” is part of the solution, it’s rarely the whole story.
2. Obesity directly causes diabetes
Obesity doesn’t directly cause diabetes, but it raises the risk of type 2 diabetes. Not everyone with obesity develops it, and not all type 2 diabetics have obesity.
Obesity is also a risk factor for gestational diabetes (during pregnancy) but not for type 1 diabetes.
3. People with obesity are lazy
Inactivity can contribute to obesity, and exercise helps with weight loss—but there’s more to it. A 2011 study tracked 2,832 adults’ activity levels and found that while step counts dropped as weight increased, the difference wasn’t as dramatic as expected, especially for women:
- Healthy weight: 8,819 steps/day
- Overweight: 8,506 steps/day
- Obesity: 7,546 steps/day
Since heavier people burn more energy per step, the actual calorie expenditure gap might be even smaller.
This doesn’t downplay exercise’s importance, but the reality is nuanced. Some people can’t be active due to physical disabilities or mental health struggles like depression, which is also linked to obesity. Others may avoid leaving home due to poor body image.
4. If your family has obesity, you’re destined to have it too
Genetics and obesity are complicated, but having obese relatives doesn’t guarantee you’ll develop it—though the odds are higher.
Separating genes from environment is tricky since families often share both. A landmark 1990 study compared twins raised together and apart, concluding that genetics heavily influence BMI, while childhood environment has little effect.
A 1986 study found that adopted children’s weights aligned with their biological parents’, not their adoptive parents’. Later research suggests environment plays a bigger role, but genes still matter.
Scientists have identified over 50 genes tied to obesity, most with small effects. One variant of the FTO gene raises obesity risk by 20–30%. However, a 2011 study showed that physical activity reduced this genetic influence by 27%. Another analysis found that lifestyle changes can partly counteract genetic risk.
Still, for some, generic advice like “exercise more” isn’t enough.
5. Obesity doesn’t harm health
This is false. Obesity raises the risk of diabetes, high blood pressure, heart disease, arthritis, sleep apnea, and mental health issues.
Even modest weight loss (5–10% of body weight) can improve blood pressure, cholesterol, and blood sugar. A BMJ review also found that weight-loss efforts may lower early death risk in adults with obesity.
Obesity is widespread, and the stigma around it is harmful. Challenging these myths is essential.