I say start with 3 days if you haven’t fasted before, then try 5 if you aren’t where you want to be. Definitely give it some time between fasts using IF with very nutrient dense keto foods. Good luck! Belly fat is a problem I have, too.
Avoid sugary drinks, high fructose corn syrup and watch yourself when you are not fasting. Fasting can help get rid of belly fat, but it will come back if you don’t watch yourself. What I sometimes do is go run on treadmill while I am hungry as long as I have enough energy to do so, and I am not drained or tired.
Hey my bodytype is pretty close to yours. [m/22y/183cm/81.7kg] Actually on the 6th day of a 7 day waterfast and was 81.7 kg on day 1. Didn’t measure again in between. I’ll just do it on the last day. Anyways I’ve done a 2 day water fast oce and am now on a 7 day. No need to ramp up as slowly as people say, I felf fine during this fast(except the hunger pangs to be expected). I’m doing it mostly for weight loss and will move into keto immediately after.