For me it depends on my weight. If I am above 123-125 lbs, I fast easily and naturally till 10 am- lunch daily. The heavier I am, the longer I can go without food without it bothering me, up to maybe 22 hours. I have done only one 24+ hours fast after the age of 23, and it was not something I would do again.
When I weigh less, fasting becomes problematic, so I have breakfast & eat more often, maybe going 4-5 hours between meals, sometimes less, sometimes more.
All and all, I just go by how I feel, and try to stop and analyse if I want food emotionally or physically before I eat.