How can you tell when you’re in fat-burning?

One of the best ways to know is your appetite. Does your appetite go away especially between meals? Can you go along for your time without eating? That's the best indicator more than weight anything. And it just tells me you're burning fat between meals. Now if you could only go for so many hours and then you need to eat. We know you're not burning fat.You're just running on your sugar up and down, up and down.