Person stepping on bathroom and scale and wondering what obesity is

What is obesity?

Written on April 14, 2023 by Gillian (Gigi) Singer, MPH. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

What is obesity?

Obesity is defined by the World Health Organization as “abnormal or excessive fat accumulation that presents a risk to health”.[1]

Obesity is often thought of as solely a result of poor diet or lack of exercise, but there are many other contributing factors to weight that, more often than not, individuals cannot control. The Preventative Cardiovascular Nurses Association says, “Understanding how [social determinants of health] interact with genetic and biological factors is essential to positively impact health outcomes. We simply cannot treat individuals within a vacuum without consideration to the environments where they are born, live, learn, work, play, and worship.” [2]

Factors, or social determinants, that influence a person’s weight include but are not limited to “economic stability, education access and quality, food, neighborhood and built environment, social and community context, and healthcare system access and quality” [2] in addition to genetics (and epigenetics), community support, mental health, chronic health conditions, physical ability/disability, and more. Read on if you have been wondering, “What is obesity . . . am I obese?”

How obesity is measured

Most articles about obesity and weight measurement will discuss body mass index, also known as BMI. However, most writers and even a large amount of healthcare providers (HCPs) don’t realize they are relying on a deeply flawed, inaccurate, racist, and fatphobic standard of measurement that deeply stigmatizes fatness.

Traditionally, your HCP will determine whether or not you are “obese” by calculating BMI (weight in kilograms divided by height in meters squared) and then comparing the result to a table. However, “BMI is just an estimate of the amount of adipose tissue we have; it does not differentiate fat from muscle and can be particularly inaccurate in certain populations such as athletes or those who are very tall or very short.”[3] Side note: adipose tissue (body fat) is necessary for human functioning.[4]

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Other BMI blunders

Here are a few other BMI blunders that are made.

Sex assigned at birth

It was developed by a Belgian mathematician named Lambert Adolphe Jacques Quetelet, “who sought to measure the height and weight of the ‘average’ man based on a sample of White, European men,” as he saw this combination as the “ideal.”[5] The female body stores 6 to 11% more body fat due to hormonal differences, and the distribution of body fat varies greatly.[6]

Corporate influence

The cut-off points for the classifications of underweight, healthy weight, overweight, or obese “have their roots in the Metropolitan Life Insurance Company’s attempt to establish ‘how weight might play a role in someone’s likelihood of dying’ in the 1940s,” according to Fatima Cody Stanford who is an obesity medicine physician scientist at Massachusetts General Hospital and Harvard Medical School.[5]

Racial and ethnic background

“Research has shown that Black and White people tend to have different body compositions,” and regarding people of Asian descent, “the WHO released adjusted cut points for people of Asian descent, who have a higher risk of certain metabolic diseases at lower BMI.” No specific metrics have been adopted for Latino and/or Black people.[5]

Using waist size as a health indicator

One measurement that is a much better indicator of health/health risk is waist circumference (or the measurement around one’s waist). Regardless of BMI, “long-term follow-up studies showed that so-called ‘abdominal obesity’ was strongly associated with an increased risk of type 2 diabetes, cardiovascular disease and death.”[7]

That said, it is important to remember that your BMI, waist size, weight, or any other measurement is not a reflection of your worth, nor is it always a reflection of your health. People with fat bodies can be totally healthy, and people with thin bodies can be very unhealthy—and health itself is inherently ableist. Health will look different for every person.

Concerns about your own weight

If you have concerns about your weight or health, the best thing to do is to speak with an HCP that will not be judgemental, will be body neutral, and uses a Health at Every Size (HAES) ideology, meaning they “Accept and respect the inherent diversity of body shapes and sizes and reject the idealizing or pathologizing of specific weights.”[8] HAES ideology proposes that “health exists on a continuum that varies with time and circumstance for each individual. Health should be conceived as a resource or capacity available to all regardless of health condition or ability level, and not as an outcome or objective of living.”[8]

If you're interested in weight loss and would like to learn more by talking with a healthcare expert, consider weight care online via Everlywell's telehealth offering.

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  1. Obesity. World Health Organization. URL. Accessed April 18, 2023.
  2. PCNA. Social Determinants of Health and Obesity. PCNA. URL. Published March 9, 2022. Accessed April 18, 2023.
  3. Adolphe Quetelet and the evolution of body mass index (BMI). Psychology Today. URL. Accessed April 18, 2023.
  4. Adipose tissue (body fat): Anatomy & function. Cleveland Clinic. URL. Accessed April 18, 2023.
  5. Why BMI is a flawed health standard, especially for people of color. The Washington Post. URL. Published May 8, 2021. Accessed April 18, 2023.
  6. Why do women store fat differently from men? ScienceDaily. URL. Published March 4, 2009. Accessed April 18, 2023.
  7. Obesity definition. Obesity Prevention Source. URL. Published April 14, 2016. Accessed April 18, 2023.
  8. The health at every size® (HAES®) principles. ASDAH. URL. Published April 22, 2022. Accessed April 18, 2023.
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