Most people (especially those who have built up some "reserves") can survive for a long time without food and would safely last months on just liquid. (treated water or herbal tea + some vitamins & minerals).
The mental benefits in terms of ability to concentrate are hard to put into words. It's different than with micro-dosing which gives you a false sense of your abilities. The long fast showed me what kind of energy gets unlocked when we feel like we're close to snuffing it. It's like the body gets ready for a final push so that you can hunt and find food. I stopped doing these crazy type of diets after discovering IF.
IF gives me a similar result (the highs and lows on the graph are less extreme but at least it's sustainable) without landing myself in hospital (in retrospect the kidney stones were most likely legacy/cruft that needed to be refactored anyway, and who knows what kind of cancers or other long term illnesses my body "ate" while I pushed him that hard). I understand this is all pretty mental to read but back in 2013 there was no IF and all I had was the theory that dogs and rats that were kept on an IF survived longer.
!!!
Disclaimer: this is the most extreme one I ever done so please don't start out with this if you want to try... try 7 days or 2 weeks are enough time to do some extreme diet. But don't go overboard - which is way too easy after 2 weeks because you'll be so high on your own achievement and you won't feel hunger. It'll feel like you're able to continue for 2 or 3 months. (you won't). the key is in recognizing this and to quit regardless! Also knowing your own body is key. E.g. if you do sports and have a 20 year history of pushing yourself to extremes probably yes. But I understand why doctors bail and give the "blanket advise" that this is irresponsible.
I did a water only fast which is documented here: https://news.ycombinator.com/item?id=16533514
The mental benefits in terms of ability to concentrate are hard to put into words. It's different than with micro-dosing which gives you a false sense of your abilities. The long fast showed me what kind of energy gets unlocked when we feel like we're close to snuffing it. It's like the body gets ready for a final push so that you can hunt and find food. I stopped doing these crazy type of diets after discovering IF.
IF gives me a similar result (the highs and lows on the graph are less extreme but at least it's sustainable) without landing myself in hospital (in retrospect the kidney stones were most likely legacy/cruft that needed to be refactored anyway, and who knows what kind of cancers or other long term illnesses my body "ate" while I pushed him that hard). I understand this is all pretty mental to read but back in 2013 there was no IF and all I had was the theory that dogs and rats that were kept on an IF survived longer.
!!!
Disclaimer: this is the most extreme one I ever done so please don't start out with this if you want to try... try 7 days or 2 weeks are enough time to do some extreme diet. But don't go overboard - which is way too easy after 2 weeks because you'll be so high on your own achievement and you won't feel hunger. It'll feel like you're able to continue for 2 or 3 months. (you won't). the key is in recognizing this and to quit regardless! Also knowing your own body is key. E.g. if you do sports and have a 20 year history of pushing yourself to extremes probably yes. But I understand why doctors bail and give the "blanket advise" that this is irresponsible.
!!!