Intermittent fasting is the broad name for diets when you fast to some degree on some, but not all, days of the week; you eat normally on the other days. On “fast” days, the kilojoule (energy) restriction is severe, at about 25% of what you would normally eat. The most popular fasting diet is the 5:2 diet pattern where you fast on two days of the week.
While this may help in achieving short-term weight loss we do not know the longer term benefits or harms and it is very difficult to stick to. Our advice is to choose a diet to help you achieve a healthy weight and one you can stick with. It should also help you feel better and be healthier.
For more info check this out: https://theconversation.com/what-are-fasting-diets-and-do-they-help-you-lose-weight-76644.