C.T.
I think that if you offer a balanced diet with a wide variety of choices, then you should be fine no matter what he eats. Be prepared and dont freak out when he hits the "eats only one food for days" phase. It's really normal. My youngest only wanted mac-n-cheese for 3 days - every meal. I went with it and just added veggies, tofu etc to supplement him. I knew it wouldnt last forever.
You can google nutrition info for nearly every food - that way you can see which are high in what nutrients and plan your menu that way.