The question of whether you should eat before speaking is a very individual one. Some people want to eat, others don’t. By the way, you are not alone in this dilemma. Most professional athletes, stage actors, and musicians do not eat a large meal before performing.
There have certainly been times in the past when I was teaching a private session on an empty stomach and my stomach started to growl. In a situation like this, it is a good idea to have some type of snack available like a granola bar or some fruit that you can nibble on; however, when it comes to speech or presentation, biting into an apple is not in the picture.
The real question is the grand presentation in front of the microphone or standing at the head of the boardroom table. Today’s good microphones can pick up a lot of sound, especially at close range. On the other hand, if you are at the head of the boardroom table, those sitting immediately to your left and right will hear all the sounds your body makes.
You should definitely have something on your stomach so it doesn’t growl during your performance; however, the last thing you want is too much. Feeling full is not good when nervousness is at its peak. If you feel like you can unbutton the top button of your pants, trousers, or skirt or need to unbuckle your belt, you definitely went overboard.
Remember, too much food in the stomach can produce unwanted audio results, as well as too little!
Eating a few hours before speaking is ideal. But what happens when you are the tabletop speaker and they have pride of place for you in the center of the podium?
Eat light.
Give up dessert.
AND
Do not drink alcohol.
While you may think that you can have a drink before you speak or that it can help you relax, I disagree. When you drink, you lose your edge. The last thing you want when speaking in public is to feel too relaxed. You need to be sharp, clear, crystallized. Alcohol does not allow any of that. It dulls the senses. So stay away from liquor. Instead, drink water, coffee, tea, or juice. Also avoid dairy products because they create extra phlegm. Excessive throat clearing when speaking is also annoying and damaging to the vocal cords (vocal cords).
The best advice I can give is to use common sense when choosing foods; have something in your stomach so you don’t starve; and save your dessert for later.