What is the recommended food to give a child with the flu?

Whatever they want: Most kids feel so crummy with the flu that they don't want to eat or drink anything. If they are hungry, that's a good sign! Give them what they want (within reason). I'd start with bland foods, especially if there was tummy-upset. No specific food will shorten the illness--only time & love! And remember pushing fluids is far more important! Dehydration is a major cause of hospitalization from flu