medical definition of obese
Obesity is an abnormal accumulation of body fat, usually 20% or more over an individual's ideal body weight. Obesity is associated with increased risk of illness, disability, and death. The branch of medicine that deals with the study and treatment of obesity is known as bariatrics. As obesity has become a major health problem in the United States, bariatrics has become a separate medical and surgical specialty.
The term 'obese' describes a person who's very overweight, with a lot of body fat. It's a common problem in the UK that's estimated to affect around one in every four adults and around one in every five children aged 10 to 11.