Dont want to eat the food at prom?

So I used to have Selective Eating Disorder and it's left me with basically quite a small range of food that I like to eat. I have heard what is on the menu at prom and we dont get to choose what dish we want to eat, and by the sounds of it ill only be having desert. But it's kinda embarrassing to just sit there whilst everyone else eats their food. I'm going to eat before I go anyway because the prom is not till later in the evening so I will be too hungry to wait, so I will mention that im not hungry anyway, but what else can I do?