How long have you had him?
how long since his last meal?
Are the husbandry correct?
Any extreme change in temps recently?
Anything new with his enclosure (moved to a new room, new substrate, etc)?
Anything new with his surrounding (new pet in the house, more noise than usual, etc)?

There are number of other questions I can ask but BP going off feed is absolutely normal. Again, this is assuming all else is up to par. I'm sure other members will chime in but first and foremost, check his temperatures and surroundings. Other than that, you have an average BP like the rest of us. Good luck..