Once you have transitioned into "fat-burning mode", you might widen your fasting window until you are fasting 16 hours a day and eating in an eight-hour window - This is known as Intermittent Fasting 16:8.
You can (gradually) widen your fasting window to 18:6 or 20:4. I have been fasting 20:4 for over fourteen months (and I do not count anything): I started by not eating after 19:30, and I gradually narrowed the window until I was only eating between 10:00 and 14:00. It works for me – but you might eat with family in the evening? Dr Berg suggested missing breakfast on 20:4.
One Meal A Day (OMAD) is IF eating one meal a day
I use this occasionally when I know I am going to have a big “party” meal, and even before Christmas, when I had big meals four days running, it let me get down to my target weight. Years ago, when I was not used to fasting, if I ate a small lunch knowing that I was going to have a large dinner, when I got to eat in the evening, I was so hungry I wolfed the food down without really appreciating it: your body has to get into “fat-burning mode”.
Some people do 24-hour fasts or you can (occasionally) not eat for two nights and a day, making a 36 to 44 hour fast.
5:2 fasting is "Intermittent Calorie Restriction" and not, I consider, IF. I do not recommend it. It is eating 500 or 600 calories two days a week - and some members here use it.
Here is a short video about a study comparing Alternate Day Fasting (ADF) to caloric restriction dieting:
Here is a long video about ADF... He is not qualified, but he talks a lot of sense. He “feasted” (ate as much as he wanted) on feast days, but, I think, he could have lost more by eating less or LCHF on “feast days”.
70lb lost in 6 months:
A lady's experience of ADF:
I think and advise that ADF or any other form of IF works so much better in combination with LCHF - without counting anything.
She is 23% body fat which (for a young lady) is in the same (athletic) band as my 14%, being a 70-year-old male.
She "sussed it out" and started off with ADF and used 4:3 later. You can, of course, use "proper IF" 5:2 - eating nothing two days a week ¿in combination with e.g. IF 16:8 on other days?
The first 6½ minutes of this video are mostly about the "spiritual benefits" of fasting (and she wonders why some people think it is a fad)... but there is some good information:
Dr Mindy Pelz advocates regularly changing between different fasting strategies:
Dr Mindy Pelz Seven types of fasting:
Why do they rank the Keto diet worst for health?