It is but social convention.
About the only things that stick are "don't stop physical and mental activity as you age" and "do stuff in moderation".
If you call it "intermittent fasting" and write a book about it, you can get a whole movement behind how healthy skipping breakfast and lunch is. And another movement preaching about how bad it is. And a followup book about what you REALLY should do ad nauseam.
As for good diets, for instance, there is a wild meal schedule that has shown to be fairly good at managing weight, it is just intense. It is the 16 to 17 meals a day plan. One meal every hour you are awake, each one only about 100 to 150 calories. It does potentially work but try selling it to people and worse getting folks to stick to it.
No: fasting has not been proven to extend lifespan in humans.
Also no: exercise has been far more provably correlated with healthspan improvements than fasting.
Also, the first thing I work on is usually a high leverage project that excites me. Reading news or answering emails (things that can affect my emotions) are usually avoided during that time. Usually.
I'd recommend everyone try fasting and figure out what their bodies really need (preferably over the holidays, because the adjustment period can be a bit rough and could interfere with work.) I suspect most of the developed world is over-eating by quite a lot given our largely sedentary lifestyles.
No, why would you think that?