oh I get you now I struggled with that as well.. My GD educators said eat if I was hungry but test before I ate and tried to space my meals out to at least 2 hourly..

Some days I didn't eat breakfast as I am not a breakfast person in general life. But I would eat around 9 or 10 when I felt hungry.

Also I assume you know about exercise? I tried to go walking in the mornings as that was when I felt I needed it the most.