Since awareness of the dangers of obesity became widespread, many strategies have emerged to counteract the condition including measuring the body mass index of an individual. However, there was no concrete basis that determines if a person is in fact obese or not. People back then assumed that extreme fatness is obesity.

This changed in 1996 when a Belgian statistician and anthropometrist Adolphe Quetelet developed the Body Mass Index (BMI). The BMI estimates the amount of body fat in order to determine obesity and its severity much like a thermometer measuring the degree of temperature.

To calculate BMI, a subject's weight (in Kilograms) is divided by the square of the subject's height (in meters) as shown in the equation: BMI=kg/m2. the resulting value is then compared to an index of numbers that defines being underweight with a BMI of less than 18.5, normal at a BMI range of 18.8 to 24.9, overweight at a BMI range of 25.0 to 29.8, obese at a BMI range of 30 to 39.9 and morbidly obese at BMI of 40.0 or higher. These definitions were agreed upon and published in the year 2000. Since its release, it has been relied on to determine a specific status of obesity and related risks.

Although BMI and obesity were meant to go hand in hand, BMI cannot be a sole factor in determining obesity and in prediction a person's cardiovascular health. In the calculation, we assume that the BMI results is body fat neglecting the type of body mass a person has. The type of body mass would be different for a muscular person and in an aging person who have lost body mass. BMI is, in fact, only one of the clinical assessments used to determine heart risks. Also, BMI does not consider the ratio between fat and muscle tissue nor does it recognize the forms of fat and waist circumference.

BMI, it seems have been quite a assistance to obesity. Despite the inaccuracy of the number, many continue to rely on this that it is used to identify persons with a certain BMI count a corresponding risk to another disease. Or even as an indicator of weight loss instead of measuring weight.

Naturally BMI cannot answer all questions regarding obesity and its health risks. It has limited coverage, obviously. Therefore it can only be a determining factor of obesity in general. It is as reliable as weighing yourself but in obvious cases of being overweight.