Water, salt, potassium and magnesium.
If you feel tired, eat some salt.
My first fast lasted 6 days, i interrupted it just because i was bored not for hunger nor tiredness.
Care about how you will interrupt it.
It is my 2nd day of water fasting and I can not stop thinking about the drawer of Oreos downstairs! So tempting isn’t it?! I am as well trying to fix my relationship with food! “We eat to live, not live to eat!”. Fainting should not be concerned as long as you receive the salt, potassium, and magnesium like shinysho said. If you are still concerned about fainting, Dr. Fung actually recommends water faster to perform exercise. I find that bordem is making me crave food opposing to if I was busy, it can keep my mind off food. However, while fasting you’re drinking tons of water is synonymous to running to the toilet daily! So you are better off fasting on the weekend!