I was able to first hand witness how certain foods can react in children. I was working with a parent of a now typically developing child (thanks to food!) and we were sitting in her kitchen.
To give you back background of my past interactions with this child, he would come in and out of the room as kids do and ask his mom questions or to request something. He has always been very polite, follows direction, interacts with me well etc. Last time I saw him we had a snack together and we had very appropriate conversation.
When I first came over today he was once again very polite, was having a play date with a friend (which was being facilitated by another adult) and having a great time. Mom and I continued our talk and about half way through he had lunch. Mind you this is something he can eat. Not something that is restricted, but not something mom gives him all the time as she tries to limit the amount of yeast he has. We continue to talk and about 15 minutes later he runs in the room and yells I hate you both and other comments and behaviors that are out of character for him. Mom calms him down, he returns to his play date and mom and I continue talking.
Over the next half hour he continues to run in and out of the room continuing to make inappropriate, out of character comments and interactions, not listening to his mom, eating flour off a plate (even though he just ate lunch) and grabbing at things. He came in as though he didn't care what is right or wrong, he just wanted what he wanted and to me he didn't even know what that was. This surprised me as this is not the same way I have seen him in the past or even earlier that day. Even after his play date leaves he continues to make out of character comments that are inapprpriate. Mom attempts to give him something else to eat to balance out what he ate for lunch.
For me this was an eye opener to watch a child react to food before your eyes and it is trully amazing. What he ate was a small amount, but his reaction and change in character was something to take note on.
Tip from this and what can you do:
Next time you notice your child is out of character or you see a change in behavior write this down and write down what they ate. This gives you a frame of reference to know how your child reacts when they eat different foods.
Why this is beneficial: from both an educational and behavioral perspective if your child is upset and you don't know why or you hear from the school your child had a "bad day" or was "out of character" this is something else to consider. Knowig this, you can be a detective and figure out what you can do different (and feed your child differently) to help your child reach and maintain their full potential.