If one types BMI on one of the largest search engines for scientific articles pubmed, there are approx 42367 articles in the subject. Now, the fact that it is so highly used is very astonishing considering its flawed validity. Most scientists are trying to get away from the concept while still, many are stuck on the concept of BMI. For most part it is shown that high BMI (above 25) is correlated with ill-health. Now BMI measures body volume in relation to hight (weight/high x hight2).
In some cases a reverted BMI scale might appear. Imagine Bob, a sportsman. He weighs 90kg and is 180 cm long. His BMI is 27,5 (Overweight) However, he has 9% fat, which means he is not fat, his volume contains muscles. But when too many Bobs enter a study, they turn up the scale (particularly if exercise and lifestyle factors are not controlled for in statistics). They show healthy results (because they exercise and have a healthy lifestyle) but an overall higher than usual BMI. Which indicates; High BMI = Good Health. Example Subject 1.
BMI, as most know is not a reliable tool for health measurement for overweight, and a moderate one for underweight. A better way to estimate and measure a third variable (obesity and lifestyle) is to measure belly fat and not just belly fat in general but bellyhight. Everyone has a belly, some belly’s are healthier than others. To exclude variations (since there is proposed health variations between pear-shaped and apple shaped) new method called Bellyhight should be used in combination with BMI to get a clearer picture of subject A.
He should be layed down on a flat surface and perform the procedure as such.
Subject A has Bellyhight of 18, perfectly normal.
This is not the ultimate way, and not clearly sufficient in itself, but will definitely increase the validity in any study aiming to measure obesity, overweight and the link to genetic, social and behavioural factors where the information on the subjects are limited. There are flaws in all methodologies but to grow we have to evolve, until new and better ways arrive.