Re: 40 day water fast
I'm just beginning Day 4 of one, now.
Typically, I do a four-day, each month (Sunday night being last meal, breaking it on either Thursday night, or, sometime Friday - usually it's been the morning, but, sometimes, I've been able to wait until later in the day), plus 2 days per week.
I do use unsweetened/un-anything tea (I use high-end loose leaf greens, oolongs, and blacks, along with - usually once during a four-day, coca leaf) and a few
ounces of (preferably) cold-brew coffee.
I've not noted any particular problems other than the thought that I'd enjoy eating!
However, I have young children, while I am not as young as the typical parent, so am doing this for life extension (planning to make it past 100), cognitive enhancement (I'm in law school), and neurodegenerative protection (my mother died with Parkinson's Disease), and so I deem it not to great a sacrifice, especially since it makes me feel stronger, overall, to accomplish even a four-day run.
I'm guessing you're Jewish, then?
I'm Christian, but fasting is certainly part of the prescription for Christians, as well, since we come from the same tradition, so, to the degree that it fulfills my purpose to dedicate myself to God, I'm glad for that, too, though I admit (to you and to God) that it's been the ancillary consideration.
I started fasting five years ago, doing 1, 2, or 3 days, but, added in the 4 day, after reading about work at UCLA, which suggested that neuro-protective benefits were derived from a 4-Day calorie reduction (few hundred, per), but, being an all-or-nothing type person,I figured that, from a willpower standpoint, it'd simply be easier for me to go cold turkey.
I've remained interested in longer fasts, but, by the weekend, I typically need to eat with my family.