When you have the flu you should only eat Bland foods such as Bananas, Rice, Apple Sauce and Toast.
This food is known as the BRAT diet and is good for both the regular flu and the stomach flu.
You should avoid eating anything containing dairy, meats, etc.
Those Ramen Noodles in those cheap packages that you can buy at the Dollar Store or Walmart are also good to eat when you have the flu.
I keep a lot of those Ramen Noodles in my pantry so that I can eat them when I have the flu as it's about all I can seem to get down and it's better than eating nothing.