Do you have to diet before a glucose test?

Bárbara • I'm 28, and I have a beautiful baby girl born on May 30th, 2017 ^^ I also have a dog named Oliver and I love him lots!
I have my 6th month glucose test on Thursday and I don't know if there are stuff I shouldn't eat days before? Are you supposed to diet? They didn't tell me anything, just that I don't have to eat anything 8 hours before the test! Any advice? Thanks! ^^