Here are some thoughts, based on evidence and theory.
(Short thread.)
Research has shown IF activates certain pathways in the body, but no study (yet) has gotten to real-world outcomes we care about.
The theoretical benefits of IF (beyond weight control) all center around it's role as a stressor to which the body adapts.
Physical activity is great and very well-studied example.
No physical activity, and you get sick. Too much physical activity, and you get sick (or injured).
If you believe intermittent fasting offers stress-related benefits, it'd be wise to consider the "just enough over and over again" approach here too.
Be a little hungry most days.
This feels like about the same hunger stress as would be a healthy workout stress. A little hard but not too hard. Very repeatable.
A full day fast once or twice a year? Fine.
-Intermittent fasting is a way to control calories.
-Any other benefits are still theoretical.
-The main theories are around positive stress-related adaptations, such as with exercise.
-Take a similar approach. Hard but not too hard. Be a little hungry most days.
-Burning out
-Binge eating in the windows you do eat
-And by far most dangerous, eating disorders
Based on everything out there:
-Avoid processed foods.
-Eat lots of plants.
-Consider a 12-hour window: be a little hungry most days.
(End.)