Another point of the medical recommendations, in my opinion, is that drinking enough water is important rather than only drinking sugary soft drinks or juice, or tea, coffee, beer, wine, cider etc.

I watched an Oz TV show which shows Police officers pulling over drivers to test them for alcohol or drugs. One memorable scene showed an old man who looked - excuse the expression - totally whacked out on drugs, like a lifelong user. He looked extremely unhealthy and talked fast and loose, very over the top. He tested negative for drugs and alcohol but told the officers that he drinks about 20 litre bottles of Coca Cola every day. I assume that is all he drinks and good old healthy plain water would be an anathema to him. I don't have anything to base this assumption on, but if he thinks Coke is the only essential drink then I also assume that he thinks Macca's (aka McDonald's) is the only essential food. Scary!