I have tried intermittent 24hr fasting a few times. It is very difficult for me and I find myself getting even more irritable than I normally am lol. So it doesn't seem to work for me.
What does seem to work for me, however, is shorter term, on-going fasting. Most of the time I do my workouts in the early afternoon. About a half hour before I get in the weigh room I eat several teaspoons full of a banana mush I make: 1 very ripe banana smushed up with 2 scoops of protein isolate, a tablespoon of BCAAs and 1 Tbs of a nut butter (either peanut or raw almond). Immediately after my workout I eat the remaining banana smush and once I'm showered and dressed I down a recovery protein shake. An hour or so later, usually around 2pm I have my first meal, a salad with lots of protein.
Later, usually around 6 or 7, I'll have another full meal. The size and type of meal will depend on whether it was a workout day. On workout days there will be more starchy carbs (rice or potatoes, etc., no wheat). An hour or so after that I'll either have a protein bar or a protein shake.
Right now though I'm attending a workout class that requires I be at the gym at 8am two days a week. I do the same routine as above only earlier and stop eating around 6 or so. Since I sometimes do double workouts on these days (morning and afternoon with aerobics after that), my last meal of the day tends to be quite large. If it was a particularly heavy lifting day, I'll have a casein protein shake about an hour before I go to bed.
By doing this kind of thing I've trained my body to eat less overall. Most Americans consume WAY more calories than they need and the result is fat gain. I'd gotten up to 250lbs. Currently I'm at a solid 190 with approximately 10 to 20 lbs of fat yet to loose. I'd gotten down to 177 but over the past several months I've had a muscle growth spurt which is at least part of why the weight has gone up. Haven't gained much fat and I know this because my waist size has remained the same, actually decreased a bit. My extremities are now where I want them to be. What's left is visceral and subcutaneous fat deposits around my abdomen. I'm beginning to see the top tier of my abs but I still have a protruding belly due to the visceral fat content.
Chucky has suggested this eating style ought to be limiting my energy level but it hasn't. I'm very active for someone my age. As well as my three to four day a week workouts and twice a week aerobics, I walk 2 to 5 miles every day and I walk briskly. My body is shaping up nicely, despite having never concentrated on working out ever before, and actually looks 10 to 15 years younger than it is. (Can't say the same for the face, lol!) I feel good, happy, focused, motivated and am getting results. Slower than I'd get if I were 40 years younger but results nevertheless.
SO... What works for one doesn't necessarily work for another. Anabolism and catabolism are complex cycles. There's also the question of how long it takes to digest foods taken into the system. On one hand we need to push our bodies to demand anabolic adaptation through maximum overload while also allowing enough rest and nutrition for full recovery, at least intermittently. I take breaks from iron lifting and aerobics three times a year, anywhere from two weeks to a month off. During this time I only walk, do limbering/stretching exercises and reduce my calories accordingly. This "time off" is the hardest for me, actually, because I miss the endorphin rush.