We do have public health campaigns. Perhaps the problem would be ok if there had been signs at all major ports saying "please do not feed the British people fibre-free food, it is not good for them" around the time when McDonalds imported itself here.

I guess that's fair enough. I guess I anthropomorphise them too much, but I always think "let 'em choose" or "live and let live". I guess I should think a bit more that the ducks don't actually choose, and are more automatic than that.