If someone invited to eat food and you will not eat.how will you say?

well there has to be a reason why you would not want to eat which you don't have to have food have a salad or a pop something like that tell them the reason why you don't want to eat infact you could just say no i'm really not hungry but i can have a pop or other beverage while you eat or you could say you have something else to do so you don't get caught up in that