You cannot control your mind from distractions. If you are actually focused on something you will automatically be free of distractions.

The best way to avoid a distraction is to satisfy it. If you feel hungry while doing a job, I suggest you satisfy your hunger and then get back to the job you were doing. If you feel like calling your Gf while you are on your Job do that. This will help you focus more on the job you have in hand.