I was actually surprised as well. I also expected Greece to be higher on the list, but maybe bad economics has an adverse effect.
I am from Spain and I can speak with knowledge of the cause. I suppose, that this will be publicity of the current progressive government. Spain can not be the healthiest country, because it is the nº1 country in Europe in cocaine consumption. Almost 25% of the population is a smoker. 1 in 6 adults suffer from obesity. If my country is the healthiest in the world, I do not want to imagine how the rest are.