If you google Sue Dengate or Failsafe Diet you will find some resources. Its all about how preservatives and chemicals can affect behaviours.

Also if you look into Sensory Processing issues... or "Out of Sync Child" you may find some interesting things... Matilda feels as though she's floating all of the time & its most uncomfortable when she tries to sit down or lay down. We use OT exercises to help her feel more "grounded". Sometimes things get mistaken for bad behaviour when its not something in their control.