Obesity

Obesity refers to an excess of body fat. In the broadest sense, obesity is caused by a long-term imbalance between energy intake and energy expenditure resulting in the storage of non-essential lipids in adipose cells. There is no clear distinction between normal and abnormal levels of body fat, and obesity is most commonly estimated by various proxies. Currently, body mass index (BMI), which is a ratio of weight to height that is calculated by weight in kilograms divided by height in meters squared, is used most commonly to define obesity operationally.