It's more common than not to have a bipolar child who craves carbs, so this may be the reason he is after them so much.
Try the gluten free diet for a week. See if you notice a difference.
Honestly, I had Missy tested for food allergies and everything was negative, except for egg whites ( which she has never had a problem with). After reading about the Feingold diet and starting it, then introducing different things, I notice a big difference when she had food coloring and corn syrup. I don't hold a lot of faith in the allergy testing.
Do you have a Whole Foods near you? I used to live up there. I'm trying to remember if I there was a natural food store, but can't. I didn't have a reason to visit them, when I lived there about 15 years ago. I know that the Shop Rite there has a somewhat decent section of gluten free pastas and cookies.
I'm not saying these ideas are all healthy but if you have a child with a gluten allergy, these snacks are "healthier" than a snack with gluten in it:
Fruit snacks (Betty Crocker brand), potato chips (check for wheat or malt), Dora the Explorer cereal, popcorn, fruit, gluten free crackers with peanut butter or cheese, cheese, Yoplait yogurt, ice cream
My kids are both gluten and casein free so they don't eat cheese or yogurt but one or both of them will eat all of those ideas.
I think if your son has been eating so much shredded wheat and you are seeing behaviour changes, you are onto something! Some people even believe if you crave a food and eat it uncontrollably, it might mean you have an allergy to it. I know all of the things I used to binge on had wheat so I tend to believe it. Good luck getting a doctor to believe this. Sometimes you just have to go with what you see.
FWIW, her therapist and I believe my difficult child was headed to a bipolar diagnosis before she went gluten free.
It is a hard path at first but it gets much easier. It doesn't have to be costly.
of course his favorite candy is skittles, which he gets rarely, although I do not notice any reaction from them, but I do on the shredded wheat, which is weird, sometimes I wonder if I am over analyzing. thank you for the advice