obesity
Last updatedDefinition
The Centers for Disease Control and Prevention defines obesity as “a common, serious, and costly chronic disease of adults and children” characterized by the presence of excess weight, as defined by the body mass index standard and the presence of excess fat. But it also operates as a cultural term full of stigma, which complicates addressing it as a purely scientific or medical question.
Clinically, obesity today is divided into Class 1 (BMI of 30 to < 35); Class 2 (BMI of 35 to < 40) and Class 3 (BMI of 40 or higher). Class 3, or “severe” obesity, was long known as “morbid” obesity, coined to justify insurance reimbursement for internal bypass surgery in people over a BMI of 40, according to the Cleveland Clinic. The term was formally changed, according to the CDC, though it remains in wide use, including in medical journals, despite the pejorative connotations.
According to the Cleveland Clinic, 42.5 percent of American adults were obese in 2017-2018, up from 30.5 percent in 1999-2000. Politically, obesity is most often referred to in context of the so-called obesity epidemic, the sharp rise in weight among Americans since the 1970s. With the rise in pounds — and with the majority of American adults now having a higher than “normal” weight — a movement has arisen to rebuke the medical, cultural, and aesthetic shaming of those in the “overweight” and “obese” categories and to question, in particular, the use of BMI scoring as an assessment tool.
BMI was first developed around 200 years ago by Belgian mathematician Lambert Adolphe Jacques Quetelet, who sought to determine what was “average” based on a white European male sample; in the 1940s, the Metropolitan Life Insurance Company developed the overweight and obese cutoff definitions as part of attempting to determine who had a higher likelihood of death for insurance purposes. The phrase “body mass index” itself was an 1972 invention of physiologist Ancel Keys, according to the Washington Post.
But body composition differs based on various characteristics. In 2018, a group of clinicians sought to update the standards to account for sex and race; the World Health Organization updated its obesity cut-points for people of Asian descent, but similar adjustments have not been made for other racial groups. The CDC recently revised its BMI charts for children to account for “severe obesity,” raising the top threshold from 37 to 60. Some scientists have suggested doing away with BMI as a measure of health altogether.
People who carry extra weight experience pervasive stigmatization and discrimination in the US, and negative bias toward people with obesity has only increased as their numbers have, according to public health researchers. The blame and shame acts to undermine the health care and workforce opportunities of people with obesity, and further compounds negative health effects. Discussions of body size and weight may focus overly on individual choices rather than systemic factors such as the US’s industrialized food system, heavy advertising of junk food, and unequal access to fresh produce, which often corresponds with other racial disparities in access to resources and quality health care.
Individuals of a variety of ethnic and racial groups have sought to popularize terms such as “curvy,” “thick,” “plus-size,” and sometimes “fat,” though these efforts are often focused on and directed at women.
If necessary to discuss body size or weight in coverage, it’s important to be clear about how obesity is being defined, and to recognize the differing societal expectations and implications of body size based on factors like race, gender, and socioeconomic status.
Additional resources
- Defining Adult Overweight and Obesity (CDC)
- Obesity Stigma: Important Considerations for Public Health (American Journal of Public Health)
Summary
The Centers for Disease Control and Prevention defines obesity as “a common, serious, and costly chronic disease of adults and children” characterized by the presence of excess weight, as defined by the body mass index standard and the presence of excess fat. The BMI dates to nearly 200-year-old investigations into the height and weight of “average” European men, and groups of scientists have sought in recent years to revise its cut-points for health risks to account for racial and sex variations. Some researchers have suggested moving away from using BMI as a measurement altogether. People who carry extra weight experience pervasive stigmatization and discrimination, and negative bias toward obese people has only increased as their numbers have. The blame and shame directed at those with obesity acts to undermine their health care and workforce opportunities, and further compounds the negative health effects of the weight itself. If necessary to discuss body size or weight in coverage, it’s important to be clear about how obesity is being defined, and to recognize the differing societal expectations and implications of body size based on factors like race, gender, and socioeconomic status.