Oh this - months ago, saw someone on FB whining about some in company wellbeing day telling her that she had the metabolic age of a 40 year old and were overweight. Lots of fee fee assuaging and asspats "BMI doesn't matter if you weight train", etc. Then me, being able to comment but having no regard for this individual: "Height and waist. If waist in cm exceeds height in cm * 0.5 you're carrying excess bodyfat with potential health implications" Thread implosion ensues.