Obesity is a term used to describe somebody who is very overweight with a high degree of body fat.

There are a number of ways a person's weight can be assessed. The most widely used method is body mass index.

Being obese increases your risk of developing a number of serious and potentially life-threatening diseases, such as:

  • type 2 diabetes 
  • heart disease 
  • some types of cancer, such as breast cancer and colon cancer
  • stroke

In addition, obesity can damage your quality of life and can often trigger depression.

Source: NHS choices