The /r/fasting FAQ and “Fasting in a Nutshell” will give you some knowledge to help prepare you!
I’d definitely recommend IF. It is fantastic to help ease you into extended fasts. Since you’ve already been keto for some time, this transition shouldn’t be too difficult (won’t get carb flu, etc).
For me, I really like extended fasting because it takes the guesswork out of everything. I’m not stressed about “is this keto? has it been 16 hours since i’ve eaten?” etc. I just don’t think about food at all. It’s a great mental break and give you some freedom away from food.
Best of luck! Keep us updated :)
Hey, welcome! My HW was 250 and my “usual” adult weight is the 220s. I hit 235 last summer and then decided to start losing. I’m down 45-50lbs and loose skin hasn’t been an issue so far - but I realize it likely will (I’ve also had quite a few kiddos!). My husband is completely on board with a tummy tuck if I want to go that route and it’s not as expensive as I thought, so that’s always on the table as an option.
I have heard that with extended fasts the skin doesn’t have issues due the autophagy playing “clean up”. Dr. Fung has this claim on his videos and in his books too. He’s not really a diet doctor as much as a kidney doc out to fix diabetes. I’ve also heard autophagy only really kicks in after 3 days.. so.. it means doing typical IF likely won’t offer the same benefits. I’ve also read somewhere that the first 24 hours are stressful on your body and you stay in a catabolic mode, which is what made me rethink my 23:1 approach.
Longer fasts are easier. I’m on my second one and today I just felt relief that I was resuming. It sounds nuts, but it really does take all of the food stuff away. I still am very busy - walk 5-8 miles daily, get approx 6 hrs of broken sleep at night! - and fasting didn’t interfere with that. There are folks on /r/fasting training for triathalons while doing extended fasts.. so I think (at least for me) the “I’m exercising lots I need to eat” is just my way of trying to justify food intake that isn’t necessary.