Measuring Obesity
There is a standard measure of a person's degree of obesity based on height and weight; it is called the Body-Mass-Index (BMI).
You can determine your BMI using the calculator below.

BMI Calculator
Height
   ft in
Weight
   lbs


In general,

BMI 22-25  - ideal weight
BMI 25-29  - overweight
BMI 30-40  - obese
BMI  > 40  - morbidly obese
  As you can see, morbid obesity is defined as a BMI > 40.

The term "morbidly obese" emphasizes that being extremely overweight is associated with increased risk of disease, including high blood pressure, heart disease, and diabetes, as detailed under Health Risks of Morbid Obesity.

Studies have shown a direct correlation between BMI and the risk of death.