There are three basic rules to follow which will make controlling your fears easier. The speaker who rushes in at the last minute does himself or herself a disservice. We all need the time to mentally prepare ourselves for the event at hand. Avoid heavy meals. This also means no alcohol, and nothing that might cause you stomach upsets.
Bananas are a good choice, they are light and filling.
It is also important to avoid taking decongestants or other medications that might make you drowsy. Use humor to help release endorphins. Laughter is a great tension reliever. Take some of the pressure off yourself by using interactive techniques. When you begin your presentation, plan to ask audience members a question and get them to raise their hands.