Shifting from “Morbid Obesity” to “Class III Obesity”

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Language around Obesity is ever-evolving, and out of respect for patients with Obesity, the term “Class III Obesity” is now preferred over “Morbid Obesity.” Using person-first language with patients with Obesity is crucial in fighting against the stigma of Obesity.

What is the Definition of Morbid Obesity?

If the Oxford English Dictionary defines “morbid” as “an abnormal and unhealthy interest in disturbing and unpleasant subjects,” making the diagnosis of Morbid Obesity sound rather ghoulish and scary, what exactly does the medical provider mean when they tell a patient that they have Morbid Obesity? Should they be offended?

The actual medical definition of Morbid Obesity is:

“A serious health condition that results from an abnormally high body mass that is diagnosed by having a body mass index (BMI) greater than 40 kg/m², a BMI of greater than 35 kg/m² with at least one serious Obesity-related condition, or being more than 100 pounds over ideal body weight (IBW).”

Because medical providers and their patients understand the word “morbid” differently (medical providers do not find their patients ghoulish), the preferred term is no longer “Morbid Obesity” but is using either “Class III Obesity” or “Severe Obesity.” This allows medical providers to communicate that this excess weight is a serious health problem without sounding judgmental. This evolving language in the treatment of obesity is important in dispelling the stigma surrounding obesity.

Obesity Levels Based on BMI

The diseases of Overweight and Obesity are classified into increasing BMI levels that typically have increasingly higher levels of health consequences. The following are levels of Obesity based on BMI:

Overweight: BMI 25.0-29.9 kg/m²
Class I Obesity: BMI 30.0-34.9 kg/m²
Class II Obesity: BMI 35.0-39.9 kg/m²
Class III Obesity: BMI ≥ 40.0 kg/m²*

Using the BMI or Body Mass Index, while simple to calculate, is problematic as it doesn’t assess for Obesity because BMI cannot tell if a person’s weight is due to muscle or excess fat. A very lean person with a lot of muscle may be labeled as having Class III Obesity!

There are more accurate tools, such as Body Composition analyzers, but these are not widely available. There is a valid argument that using a waist measurement at the level of the umbilicus or navel is a better way of determining the level of unhealthy fat.

Why Do the Definition and Degree of Obesity Matter?

Making a specific diagnosis allows medical providers to prioritize their patients’ health risk levels. The higher the level of excess weight, the higher the risk of severe health problems, disability, and early death for that patient. It also helps identify eligibility for treatment options such as weight loss surgery, program participation, or medications.

The list of potential weight-related health problems for Overweight and Obesity is long, especially for Class III Obesity. We have discovered that numerous health conditions are caused by or associated with excess weight. Reducing body weight and maintaining that loss can help to improve or reverse many of these problems.

Class III Obesity Health Risks

Problems with Obesity come from the strain of carrying excess weight, such as high blood pressure, congestive heart failure, sleep apnea, shortness of breath, nerve pain, arthritis, back pain, heartburn, leg swelling, varicose veins, and physical disability.

Other problems result from disturbances in metabolic function from having dysfunctional fat cells, such as Type 2 Diabetes, high cholesterol, heart disease, Fatty liver disease, dementia, Increased risk of several cancers, kidney disease, stroke, gout, asthma, erectile dysfunction, infertility, polycystic ovary syndrome, pregnancy complications, and blood clots.

Patients with Class III Obesity also suffer from discrimination, social bias, depression, anxiety, and low self-esteem.

Unfortunately, this is only a partial list of issues related to Class III Obesity, and the problems of Obesity are growing worldwide.

Treatments for Class III Obesity

Comprehensive treatment for Class III Obesity includes:

Dietary modification: based on medical evidence
Physical activity: adjusted to the person’s needs and abilities
Behavioral modification: to help overcome unhealthy habits
Medication: if appropriate, as a tool to help with the urge to eat
Weight loss surgery: if appropriate, for those with Class III Obesity or Class II Obesity with severe weight-related conditions. Obesity Medicine specialists can help people decide if weight loss surgery is appropriate for them, help them to successfully prepare for weight loss surgery, and help people to have the best results with lasting success afterward.
Prevention of weight regain: help with maintaining healthy habits
Understanding, compassion, and respect

As Obesity Medicine specialists, we have studied the causes, prevention, and treatment of Overweight and Obesity. By building on the four pillars of Obesity medicine treatment, we can provide education, support, and a plan to help patients overcome the disease of Obesity.

Looking for more resources to help address Overweight and Obesity with your patients? Consider OMA’s patient infographics in the following topics:

Learn more about diversity and inclusion in treating obesity or enroll in our Fundamentals of Obesity Treatment course.