You adapt to it just like anything else. If you can, read The Warrior Diet by Ori Hofmekler or just find him online. The other resource that I find amazing is The Fat Burning Man podcast by Abel James. I found Abel and the podcast while searching out stuff on Ori (he is featured for one ep), but Abel really taught me how to live the fasting lifestyle, and he goes into depth about it in the episodes. Abel fasts for most of the day as well. I dont know, it might be a trend, but like I said, I really really like it. The worst part about dieting for me was eating but not feeling like I ate enough. Turns out its easier to just not eat, and then stuff my face like a child at night..
btw, I recommend working out while fasting to get the maximum benefit. If you have more questions or whatever, I can give you my email, just let me know.