How long after waking up it the best time to eat breakfast in order to maximize metabolic function?

Answer 1

Try to eat within a half hour after waking up, even if you're not hungry. One hour maximum, but a half hour is recommended.
Also, if you're not hungry when you wake up, that's a good sign that you may have over ate the night before, so try to limit the amount of food you consume later in the day.

Answer 2

breakfast should be consumed ASAP. the sooner you eat breakfast the sooner insulin can counteract the effects of cortisol which is a catabolic hormone.