Formulas to reflect body habitus or body makeup have in recent years defaulted to the calculation for body mass index (BMI). BMI has without question become the universal yardstick used by both clinical and research science to approximate percent body fat. The ultimate goal of any measure or calculation utilizing body weight or weight for height is to arrive at an estimate of the percent body fat. Inherent in the BMI classification system is a categorical assignment into one of the following based upon height and weight:
1. Underweight
2. Normal weight
3. Overweight
4. Obese.
The formula for BMI is simple and reflects mass per square meter:
Metric: BMI = weight in Kilograms / (height in meters)2
American: = weight in pounds x 703/ (height in inches)2
Lambert Adolphe Quetelet, a Belgian mathematician (1796-1874) developed concepts and definitions for determining the “average” man. In his quest to define the average man, he developed the Quetelet index which is the same formula for what we now call the BMI. The BMI has become one of the most utilized indices of “normal” weight for height. Other formulas, measures and scales of ideal body weight have been used by various organizations, but the BMI has yet to be replaced by a simpler measure reflecting the variation in weight for height.
Pierre Paul Broca, a French surgeon developed what was probably the first set of calculations to define ideal body weight in 1871. What his guidelines really amounted to was a rule of thumb:
Women: should weigh 100 lbs up to five feet in height, then five pounds for each additional inch.
Men: should weigh 110 lbs for five feet of stature and five additional pounds for each inch above five feet.”
Louis Dublin: The historical basis for ideal body weight in the United States began in 1942 when Louis Dublin, a statistician with the Metropolitan Life Insurance Company, categorized nearly 4 million subscribers according to frame size, height and weight. What he found was those who maintained an ideal body weight from the age of twenty-five into later years, had the best chance of survival. The Metropolitan Life Insurance Company revised those numbers in 1959 and again in 1983 allowing slightly higher average weights for respective heights to be categorized as normal. Planted in this line of thinking is what we call a “normal” weight individual or “weight appropriate” individual given their height.
Realize that this hypothetical normal weight range seems to be flexible as seen by the Metropolitan Life Insurance Company increasing the “normal” weight for height as the years progressed from the original 1942 study to the 1983 publication. Some argue the original ideal weight from the 1942 study should be considered the standard, while others are using the 1983 standards.
Absurd as it might seem, the concept of what constituted a healthy body was based upon what would earn Louis Dublin’s company the most money and keep people alive longer to pay more insurance premiums. Other factors that we now know affect life expectancy, like smoking and other lifestyle exposures, the quality of healthcare, the level of stress and other potential mitigating factors, weren’t factored in. As absurd as it might seem, in the initial studies by Dublin, smoking wasn’t considered a risk factor for early mortality—the association between smoking and lung cancer was not made until much later.
Many consider the Metropolitan Life Insurance Company’s appropriate weight for height given a frame size to be unusable, in part because the frame size was never really well defined by the company. However, the scale persists to this day and is still relied upon by a few organizations to risk-stratify individuals according to height, weight and frame size.
1. Underweight
2. Normal weight
3. Overweight
4. Obese.
The formula for BMI is simple and reflects mass per square meter:
Metric: BMI = weight in Kilograms / (height in meters)2
American: = weight in pounds x 703/ (height in inches)2
Lambert Adolphe Quetelet, a Belgian mathematician (1796-1874) developed concepts and definitions for determining the “average” man. In his quest to define the average man, he developed the Quetelet index which is the same formula for what we now call the BMI. The BMI has become one of the most utilized indices of “normal” weight for height. Other formulas, measures and scales of ideal body weight have been used by various organizations, but the BMI has yet to be replaced by a simpler measure reflecting the variation in weight for height.
Pierre Paul Broca, a French surgeon developed what was probably the first set of calculations to define ideal body weight in 1871. What his guidelines really amounted to was a rule of thumb:
Women: should weigh 100 lbs up to five feet in height, then five pounds for each additional inch.
Men: should weigh 110 lbs for five feet of stature and five additional pounds for each inch above five feet.”
Louis Dublin: The historical basis for ideal body weight in the United States began in 1942 when Louis Dublin, a statistician with the Metropolitan Life Insurance Company, categorized nearly 4 million subscribers according to frame size, height and weight. What he found was those who maintained an ideal body weight from the age of twenty-five into later years, had the best chance of survival. The Metropolitan Life Insurance Company revised those numbers in 1959 and again in 1983 allowing slightly higher average weights for respective heights to be categorized as normal. Planted in this line of thinking is what we call a “normal” weight individual or “weight appropriate” individual given their height.
Realize that this hypothetical normal weight range seems to be flexible as seen by the Metropolitan Life Insurance Company increasing the “normal” weight for height as the years progressed from the original 1942 study to the 1983 publication. Some argue the original ideal weight from the 1942 study should be considered the standard, while others are using the 1983 standards.
Absurd as it might seem, the concept of what constituted a healthy body was based upon what would earn Louis Dublin’s company the most money and keep people alive longer to pay more insurance premiums. Other factors that we now know affect life expectancy, like smoking and other lifestyle exposures, the quality of healthcare, the level of stress and other potential mitigating factors, weren’t factored in. As absurd as it might seem, in the initial studies by Dublin, smoking wasn’t considered a risk factor for early mortality—the association between smoking and lung cancer was not made until much later.
Many consider the Metropolitan Life Insurance Company’s appropriate weight for height given a frame size to be unusable, in part because the frame size was never really well defined by the company. However, the scale persists to this day and is still relied upon by a few organizations to risk-stratify individuals according to height, weight and frame size.
1 comment:
.. with no adjustment for body composition, of course.
I recently had a visit from a health worker for insurance purposes. She commented that I should note I am at the top range of the weight for my height. I nodded along. She then took my resting pulse and my blood pressure, and did not hide her surprise at them being surprisingly low. I then asked her if she was going to test my body fat in any way or take measurements to take the distribution into account. She said oh, that is un-necessary. Really?
In my research, surprising differences in the UK and the US insurance industry attitudes to obesity and weight issues were revealed.
Thanks, WG. very useful.
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