I used to do it on and off for a year or more 15 years ago. I did it just for fun but noticed significantly improved productivity during the week. I too would

I used to do it on and off for a year or more 15 years ago. I did it just for fun but noticed significantly improved productivity during the week. I too would drink juice in the morning and possibly juice or 2 sugarcubes at lunch but not always and no calories otherwise. To ease into fasting I would start by skipping dinner. Skipping breakfast was then easy (for me at least) and the rest of the week was no problem. Then during a boring week in the military I decided to test what I had heard that we have 80% left when we feel completely exhausted. So after a couple of days of my "normal" fasting (IIRC) I skipped even my breakfast juice and continued without. Later that day I went to the gym and started lifting weights. 15 minutes into that I was completely drained and I was shaking for hours afterwards (again IIRC). That was my last time. :-/ I want to try again, but with a family it is way harder (and that experience kind of scared me.)