[rhinoceraptor]

It gets easier as your body gets used to it, and you shouldn't start with a 7 day fast without experience doing 24 and 48 hour fasts.

The first time I tried a 7 day fast it was like you described, I made it to about day 5 and I couldn't take it anymore. I've done about six or seven 7+ days fasts and now it's not a big deal, I feel totally fine the whole time. If I haven't kept up on electrolytes, I might get a little light headed when I stand up, but that's about it.

I use an electrolyte mix that has sodium, potassium, magnesium, calcium, phosphorus and iron. It's a bit hard to find mixes that have phosphorus, and that's the main electrolyte that is depleted in refeeding syndrome.