Religious fasting has little to do with the therapeutic ones. For a start, they are too short and are not even 24h. Second, the idea is usually to binge on cakes everyday at sunset.
The old Lenten Black Fast [1] probably applies.
- One meal a day
- No meat, lacticinia, or alcohol allowed in the meal
I am a Muslim and deny the second. A lot of us do lose weight in the Ramadan, along with our sins.
Imagine not being able to single out fasting and doing it without getting yourself into a religion. What other things can you not single out and need to delegate the thinking to religion for I wonder?