What Is Morbid Obesity?

Morbid obesity is a condition in which you have a body mass index (BMI) higher than 35. BMI is used to estimate body fat and can help determine if you are at a healthy body weight for your size. BMI is not a perfect measurement but it does help give a general idea of ideal weight ranges for height.

When you eat, your body uses the calories you consume to run your body. Even at rest, the body needs calories to pump your heart or digest food. If those calories are not used, the body stores them as fat. Your body will build up fat stores if you continue to eat more calories than your body can use during daily activities and exercise. Obesity and morbid obesity are the result of too much fat being stored in your body.

Certain medications, such as antidepressants, can cause weight gain. Medical conditions such as hypothyroidism can also lead to weight gain, but can usually be managed so that they do not lead to obesity.

Anyone can gain weight and develop obesity if they eat more calories than their bodies can use.

Some studies have shown that genetic factors can play a role in how your body stores energy. More research is being done to further explore the relationship between genes and weight.

Many behavioral factors play a role in obesity as well, including your eating habits and daily activity level. Many people develop their eating habits as children and have trouble refining them to maintain proper body weight as they age. As an adult, you may be inactive at your job and have less time for exercise, meal planning, and physical activity.

Other factors, such as stress, anxiety, and lack of sleep, can lead to weight gain. People who quit smoking often experience temporary weight gain. Women may also have trouble losing the weight they gain during pregnancy, or may gain additional weight during menopause. These factors do not necessarily lead to morbid obesity but can certainly contribute to its onset.

Your doctor will perform a physical exam and ask you about the history of your weight and your weight-loss efforts. They will ask you about your eating and exercise habits, and your medical history.

Calculating BMI

BMI is calculated when your weight in kilograms is divided by your height in meters squared. You can calculate your BMI by using a calculator provided by the Centers for Disease Control and Prevention.

Here are BMI ranges and their corresponding categories of obesity:

  • underweight: under 18.5 percent
  • normal: 18.5 to 24.9 percent
  • overweight: 25.0 to 29.9
  • obese (class 1): 30.0 and 34.9
  • morbid obesity (class 2): 35-39.9

Using BMI as a diagnosis tool for obesity has limitations. Your BMI is only an estimate of your body fat. For example, athletes may have a high weight because of their higher muscle mass. They could fall into the BMI range of obesity or morbid obesity, but actually have a small amount of body fat. Because of this, your doctor might use other tests to get an exact reading of your body fat percentage.

Calculating Body Fat Percentage

A skinfold test may also be done to check your body fat percentage. In this test, a doctor measures the thickness of a fold of skin from the arm, abdomen, or thigh with a caliper. Another way to test body fat percentage includes bioelectrical impedance, which is often done using a special type of scale. Finally, body fat can be more accurately measured using special equipment to calculate water or air displacement.

Other Tests

Your doctor may order additional blood tests to look for hormonal or other medical problems that could be causing your weight gain.

Obesity is a health concern. Without proper treatment, obesity can lead to other serious health problems, such as:

  • osteoarthritis
  • heart disease and blood lipid abnormalities
  • stroke
  • type 2 diabetes
  • sleep apnea (when you periodically stop breathing during sleep)
  • reproductive problems
  • gallstones
  • certain cancers
  • obesity hypoventilation syndrome
  • metabolic syndrome

There are several different treatment options for morbid obesity.

Diet and Exercise

There is no data on the most effective way to induce long-term weight loss, but a healthy diet and regular exercise are the keys to overall health.

It is also important to learn stress management tools that can be used in place of overeating or snacking during stressful times.

You should work with your doctor and a dietitian to set realistic goals that will help you lose weight slowly through diet and exercise. It may be helpful to find support from friends, family, or your community in order to make lifestyle changes that will lead to long-term weight loss.

Weight Loss Drugs

In some cases weight loss drugs may be prescribed. These medications may cause weight loss, but most people regain the weight once they stop taking the medication. There are many herbal and over-the-counter supplements that claim to help you lose weight, but many of these claims have not been verified.


Surgery may also be an option to treat obesity if you have tried other methods for losing weight but have not been successful in maintaining long-term weight loss. It can often help reduce the risk of other diseases (e.g., diabetes, heart disease, and sleep apnea) that are associated with severe obesity.

Surgery may cause complications, and you should talk with your doctor to determine if this is an option for you. There are two common types of weight-loss surgeries:

Gastric Banding Surgery

In this procedure, the surgeon will place a band around the upper part of your stomach. This limits the amount of food you can eat at one time by making you feel full after eating small amounts of food.

Gastric Bypass Surgery

This surgery will change how the food you eat travels through your digestive tract by bypassing a portion of your stomach and small bowel. It will make you feel full when you’ve eaten less food.

Obesity and morbid obesity are serious and potentially life-threatening conditions. A healthy lifestyle that includes a healthy diet and regular exercise are important for preventing obesity.

Diet and Exercise

People who have morbid obesity should avoid “fad” diets and focus instead on changing eating behaviors. Recommendations include:

  • adding more fruits and vegetables to your diet
  • eating smaller meals
  • count calories
  • eating mindfully
  • limiting saturated fats, trans fats, and refined sugars

Physical activity is good for overall health and is especially important if you’re trying to lose weight. To begin losing weight, you will need to do moderate to vigorous exercise for more than three hours per week. Vigorous activity raises your heart rate significantly. Be sure to check with your doctor before you begin any vigorous exercise programs. Examples of beneficial physical activity include:

  • running or jogging
  • swimming
  • jumping rope
  • brisk walking
  • biking

Moderate exercise can also include everyday activities like shoveling snow or yard work.