I had tried intermittent fasting for 3 months now. Before the fast my weight was 85 kg, after 3 months it went down to 69 kg. The process includes fasting for 12-16 hours, typically when we are sleeping. There is a 5-6 hours window time to eat usually between lunch time and 6pm dinner. After 6pm beyond, no food and only water is allowed. I hope this would help.