Class III Obesity (Formerly Known as Morbid Obesity)

What is morbid obesity (now known as class III obesity)?

Class III obesity, formerly known as morbid obesity, is a complex chronic disease in which you have a body mass index (BMI) of 40 or higher. The BMI scale isn’t always accurate. So, healthcare providers may use other tests and tools to assess obesity.

Class III obesity can lead to several serious health conditions, like Type 2 diabetes and heart disease. The good news is that it’s treatable. There’s no quick fix. But together, you and your healthcare team can create a tailored plan to reach a weight that’s healthy for you.

What are the symptoms of class III obesity?

There are no specific symptoms of class III obesity. The main feature of class III obesity is having a body mass index (BMI) of 40 or higher.

Class III obesity can cause side effects and complications in many parts of your body.

What are the complications of class III obesity?

Class III obesity can contribute to the development of several health conditions, including:

• Atherosclerosis (plaque buildup inside your arteries)
• Breathing issues, like obesity hypoventilation syndrome (OHS)
• Certain cancers, like pancreatic, colorectal, breast and liver cancers
• Depression or other mental health conditions
• Heart disease
• High blood pressure (hypertension)
• Kidney disease
• Liver disease
• Osteoarthritis
• Metabolic syndrome
• Sleep disorders, like obstructive sleep apnea
• Type 2 diabetes

Class III obesity can also cause fertility issues.

What causes class III obesity?

Class III obesity is a complex disease that has several contributing factors. The main reason your body stores adipose tissue (body fat) is an imbalance between the number of calories you consume and the amount your body uses. A lack of physical activity can play into this, as well.

But several other factors contribute to how much food you eat, the type of food you eat and how your body uses that energy. Every person’s body is unique and metabolizes energy differently. Some people are at a greater risk of weight gain than others.

Class III obesity rarely results from a lack of willpower to lose weight or a lack of “control” over the amount of food you eat.

Contributing factors to obesity include:

• Genetics. There are at least 15 obesity-related genes. Certain genetic syndromes can cause obesity, as well, like Cohen syndrome, Down syndrome and Prader-Willi syndrome.
• Hormonal imbalances. Hormone-related conditions that can lead to weight gain include Cushing syndrome, hypothyroidism and polycystic ovary syndrome (PCOS).
• Certain medications. Antidepressants, antipsychotic medications, antiseizure medications, corticosteroids and other medications can lead to weight gain.
• Cultural factors. Prevalent advertising for calorie-dense foods and increased portion sizes can contribute to developing obesity.
• Environmental factors. Exposure to chemicals known as obesogens can change your hormones and increase adipose tissue in your body.
• Financial factors. Easier financial and/or geographical access to fast foods compared to more nutritious, whole foods can lead to weight gain.
• Geographical factors. Having limited access to parks or other places to exercise can lead to obesity. Having few safe or easy ways to walk in your neighborhood can, as well.

What are the risk factors for class III obesity?

Risk factors for developing class III obesity include:

• Lack of sleep. Many studies show a link between high BMI and people who don’t get enough sleep (typically less than seven hours a night).
• Chronic stress. Long-term stress triggers the production of hormones (like cortisol) that control your energy balances and hunger cues.
• Your age. The risk of weight gain increases as you age.
• Your sex. Females have more adipose tissue than males from puberty onward. Pregnancy and menopause can also contribute to excess adipose tissue.
• Your race. In the United States, rates of obesity are highest in non-Hispanic Black people, followed by Hispanic people, then white people.

You can’t change some of these risk factors. But healthy lifestyle changes may decrease your risk of developing obesity.

How is class III obesity diagnosed?

Healthcare providers diagnose class III obesity in part by measuring your body mass index (BMI). BMI is the ratio of your height to your weight. Optimum BMI ranges from 20 to 25. You may have class III obesity if you have a BMI of 40 or more.

The BMI scale isn’t always accurate for certain populations. Providers use a different scale to assess obesity in children.

Providers also use waist circumference measurements to help diagnose obesity. In adults who aren’t pregnant, obesity may mean:

• A waist circumference over 35 inches for females
• A waist circumference over 40 inches for males

If you’re of South Asian or Central and South American descent, your provider may use smaller waist circumference values. People from these backgrounds may have unhealthy amounts of adipose tissue deep in their abdomens.

Providers can also estimate obesity by measuring skin thickness in different areas of your body.

It can be difficult to go through these assessments. It may feel like you’re being reduced to a series of numbers. Talk to your provider if you’re uncomfortable at any point.

What tests are used to diagnose class III obesity?

Your provider may recommend lab tests to check for health conditions that could be causing weight gain. They may also check for conditions that are highly associated with class III obesity. These tests include:

• Basic metabolic panel
• C-reactive protein (CRP) test
• Complete blood count
• Hemoglobin A1C (HbA1C)
• Kidney (renal) function tests
• Lipid panel
• Liver function tests
• Thyroid-stimulating hormone (TSH) test
• Urinalysis
• Vitamin D test

Your provider may also recommend other tests like an electrocardiogram (EKG) and sleep studies.

What is the treatment for class III obesity?

Treatment for class III obesity is very individualized. Every person is unique. So, you’ll need a treatment plan that’s specific to your situation and goals. Together, you and your healthcare provider can come up with a plan that treats the underlying causes of obesity. You’ll make plans to manage any other health conditions.

Management for class III obesity may include:

• Healthy lifestyle changes
• Behavioral and psychological therapy
• Medications
• Weight loss procedures

Healthy lifestyle changes

Certain lifestyle changes can help you manage obesity, improve your overall health and/or lose weight, including:

• Eating changes. A registered dietitian can help you learn about which foods are part of a healthy eating pattern. They commonly recommend the DASH eating plan for obesity.
• Physical activity. Moving your body has many health benefits — not just weight loss. Before starting any exercise program, ask your provider about what amount and type of physical activity is right for you.
• Healthy sleep. It’s essential to get healthy sleep and/or receive treatment for sleep disorders to manage obesity. Aim for over seven hours of sleep.
• Stress management. Chronic stress can contribute to weight gain. It’s important to learn to cope with stress in a healthy way, such as with meditation or breathing exercises.

Behavioral therapy and psychotherapy

Your provider may recommend doing an individual or group behavioral weight-loss program. A specially trained healthcare provider will customize a weight-loss plan for you.

Mental health conditions like depression and anxiety occur at high rates among people with obesity. Because of this, your provider may also recommend psychotherapy (talk therapy), like:

• Cognitive behavioral therapy (CBT)
• Dialectical behavior therapy (DBT)
• Interpersonal psychotherapy (IPT)

Medications

When healthy lifestyle changes aren’t enough, your provider may recommend FDA-approved medications. Anti-obesity medications can be a powerful tool in managing obesity, especially when combined with lifestyle modifications such as eating changes and exercise.

Anti-obesity medications are designed to assist with weight loss by affecting various aspects of appetite and metabolism. Providers typically prescribe these medications for people with a BMI of 30 or higher. Or they may prescribe them or people with a BMI of 27 or higher who have obesity-related health conditions, like Type 2 diabetes or hypertension.

Most of these medications mainly work by controlling your appetite rather than increasing your metabolic rate. They affect neurotransmitters and hormones that regulate hunger and satiety, helping you feel fuller sooner and reducing food intake.

Commonly prescribed anti-obesity medications include:

• Orlistat
• Phentermine
• Phentermine-Topiramate
• Naltrexone-Bupropion
• Liraglutide
• Semaglutide
• Tirzepatide

These medications each have different side effects. Together, you and your provider will decide if weight loss medication is right for you.

Weight loss procedures

Lifestyle changes and weight loss medications may not be enough. If this is the case, you may be eligible for endoscopic weight loss procedures or bariatric surgeries.

Endoscopic weight loss procedures include:

• Endoscopic sleeve gastroplasty (ESG). A provider attaches a suturing device to the endoscope to close off a portion of your stomach with stitches.
• Intragastric balloon. A provider places a medical implant (balloon) in your stomach to help you feel full and reduce the amount of food you can take in.

Bariatric surgeries include:

• Gastric bypass surgery. A surgeon connects a small part of your stomach to the middle part of your intestine, bypassing the first part of your intestine.
• Sleeve gastrectomy. A surgeon removes a big portion of your stomach, which makes you feel full with less food.
• Gastric band surgery. A surgeon places a hollow band around the upper part of your stomach, which creates a smaller stomach.

Weight loss procedures have certain risks and benefits. Talk to your healthcare provider about possible side effects and complications.

When should I see my healthcare provider?

If you’re having a difficult time managing your weight, contact your provider. You may need to adjust your health plan or try something new.

What questions should I ask my doctor?

If you have class III obesity, it may be helpful to ask your healthcare provider:

• Do I have any health conditions that are causing weight gain?
• Do any of my medications cause weight gain?
• What lifestyle habits may be contributing to my health risks and obesity?
• What can I do about the challenges I face in managing my weight?
• Do I have any health conditions that obesity is causing?
• What are the treatment options for obesity?
• Should I see a dietitian or nutritionist?
• Should I see a mental health professional with expertise in weight management?
• Is weight-loss medication or surgery an option for me?

What is the prognosis for class III obesity?

Without treatment, class III obesity can lead to:

• Several physical and mental health conditions
• Reduced economic and social opportunities
• Reduced quality of life

It’s possible to treat class III obesity and improve health outcomes. Research shows:

• Some people who take prescription weight management medications lose 10% or more of their starting weight
• People who undergo bariatric surgery may lose 30% to 50% of their excess weight in the first six months. They may lose 77% of excess weight 12 months or more after surgery
• People who had bariatric surgery could maintain a 50% to 60% loss of excess weight for 10 to 14 years after surgery

It can be daunting and overwhelming to try to lose weight and change lifestyle habits. Know that even a 5% to 10% weight loss can significantly improve your health by lowering blood sugar, blood pressure and triglyceride levels. It may also improve your quality of life.

What is the life expectancy of someone with class III obesity?

If untreated, class III obesity may shorten your life expectancy by up to 14 years. Cardiovascular disease and cancer are the greatest health risks associated with obesity that can lead to death.

Why was class III obesity called morbid obesity?

Two healthcare providers coined the term “morbid obesity” in 1963. They did so to justify insurance reimbursement for the cost of intestinal bypass surgery for weight loss in people with a BMI over 40.

In a medical setting, “morbidity” means illness or disease. The medical meaning of “morbid” is appropriate in describing this type of obesity since class III obesity is considered a disease.

The problem is that, like many words, “morbid” has another meaning. Outside of the medical setting, “morbid” means disturbing or unpleasant. Since most people aren’t familiar with the medical definition, they connected morbid (class III) obesity and people with obesity to those negative words.

Now, healthcare providers, researchers and health organizations use the term “class III obesity” in place of “morbid obesity.”