Earlier this year I became aware of a European ruling which, from what I understand, basically means businesses should not market bottled water was a way to stay hydrated. The problem I feel is using words which have a medical meaning and then the words start to be used by marketers. A good sounding official word lends credibility to the claim which helps sell the product. This leads to misinformation and people making poor decisions with regards to their health. The above sign is displayed at Hungry Jack's in Eltham.
I'm not expert in this area, but I have watched one person who was advised by a doctor to drink plenty of liquids (a well known sports drink) which resulted in them being severely dehydrated (having depleted salts from their body) and ended up in hospital for quite some time in a very dire medical situation.
What I found interesting is it appears Dr Andreas Hahn and Dr Moritz Hagenmeyer of the Institute for Food Science and Human Nutrition at Hanover Leibniz University mounted a test case and the outcome doesn't appear to what they necessarily wanted.
From this article in the Daily Mail, it appears to me they were looking for a way to market products, whereas the test case worked against that outcome. Here is a link to the EFSA (European Food Safety Authority) Scientific Opinion.
On the one hand I'm disappointed, although it should be expected, that scientists would use their skills for advertising, what is good, is the scientific opinion seems to have produced the appropriate outcome. Dehydration is a medical condition and marketers shouldn't use words which may mislead people for the sake of business profits.
Creator of the preferred Australian English spelling dictionary.