I would start with looking at your sleep.
Everyone requires a different amount of sleep to be optimum. It's not only the length of time, but how quality the sleep is. Try tweaking your sleeping habits and sleeping environment.
For example, if you're under 8 hours, add an hour to your average sleep for a week. If you're pushing 9 hours, remove an hour for a week. Or if you sleep with the TV on, try it with it off, try to make it darker, add soft white noise, different pillows, different food before bed.
The next thing I would look at is your eating. Be sure and spread your meals out and eat a balanced diet starting with early in the morning.
AOL Health