I began 16+/8- IF in 2012, and today I see it, along with food quality, as a linchpin of my dietary health strategy. IF is magical for me because it is cure, prevention, and confirmation all in one:
Cure. The low insulin period in every day allows fat cells to disgorge fatty acids to be burned as fuel. This promotes metabolic flexibility and cellular mitochondrial health throughout the body. In turn, healthier cells improve organ function, overall health, and sense of wellbeing.
Prevention. I have a large per-meal capacity and a tendency to overeat. The 16+ hour fasting commitment reduces my overall daily appetite. If I have a large first meal, I'm often not especially hungry for dinner six or seven hours later, and I will eat less. If I were skipping a midday meal instead of a morning meal, I would tend to eat heavily both times.
Confirmation. IF should be easy. When it's comfortable to go for 16, 20, or more hours without food, I know that my body is functioning correctly. Pangs should come and go without jittery or "hangry" feelings.
To reach the lower bounds of 16+/8- IF, I recommend an incremental approach, proceeding to the next once the current one has become comfortable:
Phase 1. Stop eating after dinner.
Phase 2. Delay breakfast one hour.
Phase 3. Delay breakfast two hours.
Daily IF. Skip breakfast.
That's it - IF can be as simple as not snacking after dinner and skipping breakfast.