Though I am now mostly just trying to maintain my current weight after losing the majority of the excess, I still pretty much do intermittent fasting. The eating window will vary for people depending on their routine, etc. Meaning I eat between an 8 hour time span and nothing but water, tea, or coffee for 16hrs. A lot of people think 16 hours without food is a long time, but not really. Because of course I also sleep in that 16hrs. Plus I am retired now and seldom get up before 9 AM. I had a late-night snacking problem which really added up the calories and found this helped with that. But naturally one still has to be mindful of what they eat and how many calories one consumes during the eating "window". The 8 hr window works for the majority of people. Not a good idea to skip a whole day without eating. This messes with one's metabolism, digestion, etc. Which will also affect energy levels, etc. Obese people need to be consistent.

Never done the fasting thing