I think, theoretically, insulin should be lower and growth hormone higher on a 3 day fast.
Maybe the best option is to mix the two? One week of 3x/week; one week off; one week with 3 days straight.
I found that I could do too many 36 hour fasts, and it got so that I was freezing when I tried to fast any time at all. I had to take time to recover. So, I’m not a big believer (anymore) of doing a lot of fasting, without “enough” feasting. The trick is to determine how much is enough feasting.
Right now, I’m just trying to get back to one 36 hour fast per week. That might be all I do, until I do a long-term fast, probably 4.5 days. That’s one I can fit into a week, so eat Sunday evening, then again Friday morning sometime.

Not sure how long, but thinking a longer one might fit nicely.
I eat little sodium anyway while many people drink salty water even for 16/8 and need 3 times as much sodium, apparently. And there are people who are fine without ever supplementing it (they probably don’t do very long fasts and there are other special circumstances when we lose electrolytes, of course). Our sodium intake may affect many things and both too little and too much is a problem. Maybe some people can’t eat too much and some can’t eat too little under normal circumstances…
But it starts to get better now I think. My more satiating woe helps not to think about food so often. My original keto never could do it. I am too obsessed with food and eating in general, I love reading and writing and thinking about it and experimenting… And it’s a nice hobby to some extent, I suppose but I need more creative ones. But changing and finetuning my woe helps with these mental problems too.

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