There has been research showing that caloric restiction has anti-aging benefits, although a well established and controlled diet is required due to risks.
I personally fast in the morning, and will break fast with coffee or Caffè Americano with heavy cream and a teaspoon of dried MCT (coconut milk powder). The caffeine and MCT provide my both a physical and mental boost for my day, and if I don't follow my routine, it's missed.
I don't run a large caloric deficit, my dietary goal is not weight loss. I am looking for a complete diet with low carbs, high fat, and moderate protein. I have a high stress, high energy life, this is what works best for me.
Again, thank you for the great post, you consistently post great content.