The teen turns 18 on Thursday, but won't celebrate with a beer.
He said: "I don't touch it! I shall just be going out for a meal because I don't tend to do parties.
"I've had some stick for it but I'm doing what's best for my body and my health so I can go out and perform. So far it has been worth it.
"In the Premier League there is a lot of scrutiny. It's important that I stay out of trouble."