I am not a health professional.

I don't think BMI is a good basis for prosecuting an argument about obesity.

I do think there will be a lot of un- and under- diagnosed obese people. But this BBC piece isn't how I'd like to try and understand the story.

In my own economy (Australia) there's both an epidemic of weight related health problems and a massive rise in younger and older people's activity levels over the last 10 to 15 years. An explosion of gyms, far more women visibly exercising, doing significant cardiovascular and weight bearing exercise. And reductions in smoking.

It's a complicated story.