Do have a good diet plan ?

I take whey protein shakes 2 times a day after each workout I blend it and put half a banana in it. I do this 2 times a day and in between I'll have a grilled cheese sandwich. I read each label on all the foods and rounded the calories to about 600 calories plus I might have a very small dinner so that adds up too about 700 calories...is this good or should I add something to my diet??