‘Intermittent fasting’ is a new phrase, but fasting is very, very old.
Fasting is part of your biology. You have evolved to fast. It helps you thrive.
When your relatives, about 70,000 years ago, could not find food for a few days, it would not kill them. Their bodies had stored up appropriate amounts of fat from previous meals, which could be used for energy.
Your body still does that today.
In addition, when your body doesn’t have any food for hours, or a whole day, your cells clean themselves of junk. This is called autophagy.
That’s why just about all religions have periods of fast built into them … because it worked, as a part of life, before we had organized religion.
So, if you hear that today is Yom Kippur, and Jewish people are fasting, you have a bit of context. Yom Kippur has other meanings, but the fasting has roots even deeper than the holiday itself.
The same is true for Lent, Ramadan, and Crossfit.
Intermittent fasting is much older than all of those things.