Due to problems with potassium levels and horrible cramping during treatment if recommend you eat bananas and other foods high in potassium.
I'd stay away from a lot of sugary foods as well as citrus, but I have always eaten a healthy diet (that I think held me in good stead with all this) and I have always tried to stay away from sugar and processed foods as much as I possibly can. Just eat healthy and don't go too long between meals (you'll feel better, if I went too long between a meal I felt weaker) that's just my opinion, others have theirs. Good luck!