Afternoon blues..

Don't know why I always feel so hyper sleepy after lunch everyday, even if I don't take a very full lunch! Feel like taking a 15 min nap sometimes after lunch before going back to work, but then again, I don't like the feeling of being roughly disturbed from sleep, I think i'll get a worse feeling of sleepiness with a slight headache if i really do that!!

I wonder wat r e remedies for such a thing? pls don't give me that crap about not enough sleep cos i definitely sleep more than 7 hours a day liao, don't tell me tat isn't enouhg?