Are there really?

If we ignore alcohol. We have few groups:

1) Coffee / tea (caffeinated so many cant sleep after them)

2) Yerba mate (isnt it the same group as caffeinated drinks? Also availability is low)

3) sugary drinks (cola, fanta, soda..) - basically liquid diabetes

4) juices (they are sugary again even if other type of sugar)

5) milk (nobody sells / buys milk?)

6) water with lemon

So if you want to sleep, dont want sugary drinks you are left with water with lemon.