If you’re fresh in the morning then do the difficult meetings then. Choose the time that’s best for you.
If you generally are dozy after lunch, then consider two things:
- If you can, don’t schedule important meetings then
- If you’re not yet powerful enough to do this, then do what you can to reduce it: drowsiness after lunch changes if you eat different food, if you go to the gym, if you take a nap.
Remember you’re in charge of you.
Dan Pink recently published a whole book about it. Go read When: The Scientific Secrets of Perfect Timing.