Heidi, I've personally tried to go back to my old ways of skipping breakfast & lunch and then only eat after 5pm.. but dropped the idea after just 2 days as my body just literally FROZE!
Then dabbled with 2 meals a day = breakfast @ 10am and dinner at 10pm for over a month, nah, maintenance dropped on it: added fruit which helped immensely.
But the actual diet that pleases me most of all and has sped up fat loss once again was
10am: breakfast 1-2hrs after rising
4 or 5-6pm: egg-based meal @ 4pm when I train, otherwise a protein-rich salad
6-8pm: a slowcarb drink when training, sometimes some extra carbs when I feel really tired upon returning home.
10-11pm : a heavier meal , with extra carbs the night before training (switched from eating more after training as this gives better performance)
So, there's 2 distinct non-eating windows. One at night that's nearly 12 hrs and another one that's somewhere between 6 and 10 hrs, depending on whether I'm rising early or not. I'm self-employed and mostly work at whatever time pleases me. Sometimes I wake up early, other times extremely late, like today since I've slept 11hrs (am ill).
My figuring is that most will benefit from lowered blood sugar levels and hence somewhat better body recomposition during the fasting period. And indeed, so do I. But the fact that you're fasting for 16-20 hours or longer makes you run more on adrenalin and less on food as fuel . I've been diagnosed as slightly hypothyroid and this explains most of the puzzle.
And this also seems to make me especially vulnerable to LBM loss. Despite high body fat levels, I lose excessive amounts of LBM once things don't go like they should go (overtraining, undereating by more than 15% etc.). This shouldn't happen, but it DOES.
So.. how about a sensible 3 meals a day, but just take out the energy-sapping lunch. Fasting DOES make me feel more alert, which I love.. and clearly is the reason why I used to do it all the time. But if all it does is lower your metabolism and you end up losing LBM instead of fat.. then it's not for YOU!
Contrarian and anti-KISS!
diet: back to 3 square meals but skipping lunch = 2 short fasts.