So.. you want to trip balls whilst water fasting?
In general, if you are at the right state of mind and have had experience with it before, I would say go for it.
Keep in mind that LSD is not a ‘feel good’ drug. Its a psychedelic, which means it exaggerates your psycological state of mind and anything that you might be feeling.
If you have any anxiety, stomach hunger, healing crisis going on that day, I’d suggest to skip it. It will exaggerate this. Unless you are extremely head strong and understand how to focus on other things you might have some luck.
In general though it will suppress the appetite. So if you were thinking about food that day. You might find that it will disappear over the next 24-72 hours.
Make sure to hydrate before hand, and have some water available next to you.
Fasting can boost your mental focus on inner peace. Thoughts are already clear and you are in harmony more with yourself. LSD will likely take this to another level – so I envy your trip, and wish you psyconaughts a great time.