Fat children ‘should be taken into care’

... and psycho-social issues eg. self-image, conformism, consumerism, role models, non-information rich diet...

+1

Added to this being the videogame generation, and Thatcher allowing schools to sell their playing fields to supermarket chains, poorer people buying cheaper and more fatty foods, parents not allowing their kids outside to play as much anymore, etc etc etc.

Mikec is right, insofar that young children shouldn't be unhealthy, since they should be out playing alot. But social factors, as alluded to by BMMF, are probably the most important factor in obesity. Genetics can create big people, and social conditions can make them unhealthy.