Devised between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing "social physics",[2] it is defined as the individual's body mass divided by the square of their height - with the value universally being given in units of kg/m2.
†
† The factor for UK/US units is more precisely 703.06957964, but that level of precision is not meaningful for this calculation.
BMI can also be determined using a table[3] or from a chart which displays BMI as a function of mass and height using contour lines, or colors for different BMI categories. Such charts can easily allow two different sets of units of measurement to be used, which is often useful.[4]
The BMI is used in a wide variety of contexts as a simple method to assess how much an individual's body weight departs from what is normal or desirable for a person of his or her height.There is however often vigorous debate, particularly regarding at which value of the BMI scale the threshold for overweight and obese should be set, but also about a range of perceived limitations and problems with the BMI.
Despite a wide range of other, differently calculated, ratios having been proposed,[5] none have yet been as widely adopted.
UsageEdit
While the formula previously called the Quetelet Index for BMI dates to the 19th century, the new term "body mass index" for the ratio and its popularity date to a paper published in the July edition of 1972 in the Journal of Chronic Diseases by Ancel Keys, which found the BMI to be the best proxy for body fat percentage among ratios of weight and height;[6][7] the interest in measuring body fat being due to obesity becoming a discernible issue in prosperous Western societies. BMI was explicitly cited by Keys as being appropriate for population studies, and inappropriate for individual diagnosis. Nevertheless,