I find not eating throughout the day helps me to maintain stable energy levels and focus. Also, on even on the vlc days I'm not any hungrier because I had a full meal the day before. No hunger pains or cravings at all.
One of the strangest sensations is still pooping 2-3x the next day even though I haven't eaten anything. You quickly realize that all the food you ate takes longer to fully process than you thought.
I usually eat after work and going to the gym. In order to make sure I can still exercise; I just make sure to have some electrolytes in the water I take to my gym and I'm usually fine. Sometimes it gets sketchy on intense days, but if I know it's going to be a hard day in the gym, all I need is about 30-50g of carbs and I'm fine.
My diet still isn't very good. Typical American diet. However, I find it easy to eat high octane foods that used to put me on my ass literally or mentally if I've been "fasting".
Fasting is my favorite way to maintain and lose weight. It's very braindead, time efficient, and cheap once you get used to it. After you become more aware of your bodies hunger sensations and all the habits you have wrapped around food, the biggest thing with "fasting" is making sure you get enough electrolytes.
I've done a few pure water fasts up to a week in duration and a few 2-3 day dry fasts with one four day one. Pure water fasting I tend to be fine for about 4 days and then my energy/focus will start to drop. Dry fasting it happens in about two days.
Technically it's not fasting with the electrolytes. But for weight loss, it doesn't really make a difference.
It's interesting watching science tease out the benefits of very low calories versus very low calories and a restricted eating window. In a weight loss context, I don't think it matters that much really in terms of additional weight loss.