I have for a time put on weight during intermittent fasting (daily 16-19h fast) easily, simply by ingesting excess calories in the "feeding window" for days/wee

I have for a time put on weight during intermittent fasting (daily 16-19h fast) easily, simply by ingesting excess calories in the "feeding window" for days/weeks on end. If you need 2000 a day and eat 2500-3000 a day or more (averaged over a longer time span), fasting isn't going to reverse that fact. Sometimes it is as simple as calories-in-calories-out.. I did this on purpose to grow some muscle, but some of the "gains" in that approach will always be bodyfat.