Sadly, the BMI indices are wildly inaccurate
wiki
//Because the BMI depends upon weight and the square of height, it ignores basic scaling laws whereby mass increases to the 3rd power of linear dimensions. Hence, larger individuals, even if they had exactly the same body shape and relative composition, always have a larger BMI. Also, its assumptions about the distribution between lean mass and adipose tissue are inexact//
They have of course served the slimming industry well in recent years, but most people who try it soon realise they would need to be 'skeletal' to achieve a 'normal' bmi.
I think it does more harm than good.
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