Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health. It is defined by body mass index (BMI) and further evaluated in terms of fat distribution via the waist?hip ratio and total cardiovascular risk factors. BMI is closely related to both percentage body fat and total body fat.Only 3.6 percent of Japanese have a body mass index (BMI) over 30, which is the international standard for obesity, whereas 32.0 percent of Americans do. A total of 66.5 percent of Americans have a BMI over 25, making them overweight, but only 24.7 percent of Japanese. With a suitable diet, anti-obesity drugs may be taken to reduce appetite or decrease fat absorption.
If diet, exercise, and medication are not effective, a gastric balloon may assist with weight loss, or surgery may be performed to reduce stomach volume and/or bowel length, leading to feeling full earlier and a reduced ability to absorb nutrients from food.Excess weight, especially obesity, is a major risk factor for cardiovascular disease, Type 2 diabetes, some musculoskeletal conditions and some cancers. As the level of excess weight increases, so does the risk of developing these conditions. In addition, being overweight can hamper the ability to control or manage chronic disorders.