Use this BMI formula in calculating your body mass index. The mathematical formula is a tool in an overall assessment and has an inherent flaw.
Mathematics is a tool we humans use to solve problems. We use the figures as a representation of something real in order to get answers. When you then say these numbers are real, by golly, do you get yourself into trouble with your results. The numbers themselves are not real even though we suppose so to employ mathematics.
This is particularly true when the formula you are using requires a corrective function to be used to get a correct answer. In this case, you must multiply by 703 in the body mass index formula. If you do not, you will not get a number that makes any sense. This is trying to correct the math, which does not work out without some fix. It also means that there are indeed some unknown factors involved that must be accommodated within the calculations.
You will find that this is true for all formulas that have a corrective action needed to get a correct answer. You can know for certain that in such a case that there are some unknown influence(s) that must be accommodated for when translating the problem into mathematics.
Let me give you an example: The sizes assigned to clothes are not going to mean the dress will fit you. Perhaps our own vanity is here being played upon as the solution to why sometimes it is a fit and sometimes not.
On the other hand, in the case of the BMI formula, your results do not necessarily translate to an accurate reflection of the real thing it is trying to represent―that is your body size as compared to height and weight. For one thing, your weight may be composed of more or less muscle tissue. Muscles are denser than fat tissues and so weigh more.
Other factors are bone density and skeletal structure. Larger bones would therefore result in a heavier weight. Careful here though, it is too easy to shrug it all off with “I am big boned.” With 50% of Americans overweight, certainly that does not mean they are all big boned. If you check the size of your wrist, you can get a pretty good indication of your bone structure.
As for bone density, this refers to the porousness of bones. Low bone density is found in osteoporosis. If bones lose their mass, they also loss their strength and ability to sustain a workload. Thus making you prone to broken bones. This is yet another limitation of the BMI formula because when using numbers and formulas to represent life you can fail to look at what is in front of you―life.
Therefore, yes the BMI formula is a tool used in an overall assessment of health and fitness. How to get fit and healthy is not the result of a mathematical calculation; it is an actionable target.