Yeah,
Only water 1hr before the ritual...but must fast with no food for at least 6hrs. I usually try to fast and drink tons of water for 24 hrs. I also drink lots of Guayusa/Honeybush/Rooibos/Cacao tea.
But yeah no food, and it is typically drank in the morning by indigenous peoples (I believe if I remember right). For those that don't like to fast especially the morning is best.
Blessings