It’s not black and white though. The body does adapt and respond to just reducing calories in or fasting.

It’s better to do portion control, consume fiber and better calories, and exercise to increase metabolism.

That all balances the calories out side of the equation in ways where fasting itself won’t.

https://theconversation.com/its-time-to-bust-the-calories-in...

https://theconversation.com/is-weight-loss-as-simple-as-calo...