Obesity is the condition in which the weight and accumulated fat of a person has reached a level that significantly affects their health, longevity, circulatory system, respiratory system, skeletal system and sleep in addition to other parts of their life and body.
Many public health officials, doctors and even First Lady Michelle Obama have called attention to obesity in recent years due to the alarming pace at which it seems to be rising. The World Health Organization estimated that as of 2008 approximately 1.5 billion adults (age 20 and above) were overweight and of these more than 200 million men and nearly 300 million women were obese.
The organization went on to project that by 2015 approximately 2.3 billion adults will be overweight and more than 700 million will be obese.
Medical professionals often define obesity as a measurement of the Body Mass Index, which is a ratio of height and weight. Someone with a Body Mass Index, or BMI, of greater than 30 kg/m2 is considered obese. People with a BMI between 25 kg/m2 and 30 kg/m2 are considered overweight or pre-obese.
According to the World Health Organization, the fundamental causes of obesity are lifestyle-related: the intake of excessive calories on one hand and the lack of physical activity to burn those calories on the other.
In addition to lifestyle issues, a few cases of obesity have been known to be caused by genetic predisposition, endocrine problems, pharmaceutical drugs and mental illness.