Generally, singers should avoid consuming ice cream and other dairy products before singing. Dairy foods cause phlegm and mucus to build up. That mucus is thick and makes you want to clear your throat. Unless dairy products don’t bother your voice, avoid ice cream and any other dairy products before singing. Make the mad dash to the ice cream store after practicing.
What should you eat or drink? Water is a safe bet. Some singers say they don’t like cold water right before they sing. You can experiment with it to see whether it makes your voice feel different.
Other singers may tell you to drink water with lemon or fruit juice to clean out your throat. It won’t do any harm if you want to try it, but it might not be beneficial. In fact, lemon is a diuretic, so it may dry out your throat.
Experiment with any food or drinks before the day of a performance so that you know exactly how your throat feels afterward. Eating a couple of hours before a performance also gives your body a chance to digest the food and gives you some energy for the performance.
Some people like to sing on a full stomach, but you need to experiment singing right after eating to know whether it affects you. On the day of a performance, eat familiar foods; you don’t want any surprise digestive problems during the show.