There are two kinds of fast. There's a working fast, and the there's a spiritual fast that i read about in the book. A working fast is you wanted to actually show up to day. You don't want to be hypoglabicy. And if you're either still hungry or you are looking at doing a longer term citosis, you can add pre biatic fibre. This is a kind of fibre that your body cannot digest, but the good got bacteria, they eat thos so you maintain healthy got bacteria which can actual help with weight loss. If you have coffeinthe morning anyway, probably f erl like 70 % of people who drink it every morning