Obesity is a condition in which excess body fat has accumulated to such an extent that health may be negatively affected. It is commonly defined as a body mass index of 30 kg/m2 or higher. This distinguishes it from being overweight as defined by a BMI of 25 kg/m2 or higher.
Excessive bodyweight is associated with diseases such as cardiovascular disease, diabetes, obstructive sleep apnoea and certain types of cancer and osteoarthritis. It is associated with reduced life expectancy. In the US, obesity is the second-leading cause of preventable death after smoking
