I might start with a shorter fast first honestly. I’ve done a 3.5 day fast, then 4, then 4.5, then 6.5 (meal timing thing).

The first two fasts, I was sooo ready to at at the end and could NOT stop thinking about food. My last two fasts were comparatively a breeze and I felt like I could have kept going but I had plans that revolved around food/alcohol and wanted to make sure I broke my fasts with enough time before those events.

I honestly never prep for fasts. It tends to be a decision I make a couple days ahead of time, though I’m doing it for health reasons not weight loss. But I’d suggest seeing if you can fit in a 4 day fast before your week long one and see how it goes. It seems like the body starts to realize what is going on after a couple extended fasts and they get much easier.

I also find it easier to have a flexible approach to duration of a fast. I usually end up extending fasts rather than breaking early, but I think it takes some of the mental burden away from fasting.

I actually really enjoy fasting but that could be a byproduct of my messed up digestion. No cooking, no dishes, no grocery shopping! Plus mentally I feel absolutely great! And surprisingly good workouts. You will start to feel weaker towards day 6 however IME.