Re: Impacts of a 3-day fast
I noticed sleep was actually a little easier when fasting. But I had no trouble shoveling snow or taking a walk or whatever physical activity was called for during the day. Obviously, YMMV. After a couple days, you do definitely need electrolytes. The classic way (Gandhi, IRA prisoners, etc.) is salted lemon juice, which has virtually no calories. Without electrolytes, you will be risking some cardiac problems. The tunnel vision sounds like there might have been a drop in blood pressure, but it could also be that not eating triggered a mild migraine....you can get migraine precursors and not have it turn into a full-blown headache. We're all in the realm of anecdote here, of course, but that can lead us towards some interesting hypotheses.
My spouse does all her eating between 9AM and around 4PM, and her body is completely adapted now to the microfast. She didn't even really set out to do this, she seems to be someone with really good blood sugar regulation and this practice fit her schedule. But staying at her high school weight has been a positive reinforcer, I'm sure. What I envy is that she seems able to eat absolutely anything she wants during her daytime window of eating opportunity. Quite remarkable to see this slender girlish lady putting away the sweets, whole milk, fatty foods, rich cheeses, nuts, etc. But it sort of makes sense - if you're not going to eat for 17 hours, you want calorie-dense food when you do. And fatty foods that digest slowly, release energy slowly and avoid that carbohydrate seesaw effect that's so hard on the body.