Indeed, weight. — they all use b.m.i. as an indicator, rather than the far more reliable b.f.p., because they are hampered by the fact that the latter, correctly, indicates that most body builders are very unhealthy, and the former, as one of it's many problems, fails to correctly indicate that, or even indicates that they are overweight, when they are severely underweight.

And correct science is a politician's greatest enemy, for it demonstrates that his ideals and morality are arbitrary, and that the explanations he proffers to substantiate his moral control are purely ad hoc.

The very reason they choose b.m.i. is because it was never about healthy, as they proffered, but about subjective æsthetics standards, so they needed a scale that indicated that, rather than health, all the while masking as one that was reflective of health.

That's just red tape.

That is, if you're a model, you just have to get a doctor to "certify you healthy", which I'm sure isn't at all difficult as they can pick any doctor. Note that the modelling agency will probably "help" with this, as it's very much in their interest to do so. And note the quote from BBC: "But the final version, backed by MPs 2015, allows doctors to decide whether a model is too thin by taking into account their weight, age, and body shape." (so the decision is arbitrary).