I remember a spell in hospital, post surgery. The nurses talking about BMI and for amusement they measured mine and I was also in the obese category according to the figures. It was quite laughable as I hardly had an inch of fat on my body, as the nurses pointed-out (I used to hit the gym a lot back then). They agreed it was complete rubbish too. One sincerely hopes that the MoD's quacks regard BMI in much the same way!