Learn from the mistakes of others

We have adopted the US 'experts' culture to a large degree. [Says the 'expert' :D]

Clothing sizes, for example, are based upon a survey of average body sizes by the US Army during WWII when they decided to mass produce uniforms to reduce costs. The average fit soldier is no reflection of the average non-soldier.

We have become a risk-averse culture, following the lead of the US. Being 'normal' or 'average' build means somehtign different now than it did 50 years ago.

And we live a much less active, more sedentary life now. With loads more junk food options, just to make it interesting.

I agree with your point about the 'standard' charts - though more recent versions have revised the age, height, weight relationships. I'm not sure how the Body Mass Index thingy works either.

The politics of healthcare are complex and laden with 'values' and 'interests'.