Water

Drink only water, and lots of it!

And, if you want to, a few cups of unsweetened coffee or tea a day are fine too (with a splash of milk if you like or have a sensitive stomach).

Everything else is to be considered an ideally very occasional treat which I recommend diluting with water or plenty of ice if you really absolutely want it. Same for the often as healthy considered juices and smoothies by the way. As also expressed in other blog posts: I'm team "chew your food, don't drink it"!