Parenting a child with ADHD is of course, an extra challenge, and we would all want to know if there was a quick fix solution.  Diet, particularly sugar, is often blamed for children's hyperactivity and there is a certain truth to this.  While no food can cause the development of ADHD, many parents notice that their children have food sensitivities that can lead to adverse behaviour.  Sugar is a problematic food for many of us, but other ingredients to look out for include food dyes, corn syrup, dairy, salicylates, MSG, wheat, and artificial sweeteners.  ADHD has also been linked to a lack of omega-3 fatty acids in the diet (see the article on this site for more information).  If you'd like to explore whether your child does indeed have a food sensitivity, I would recommend eliminating the above mentioned ingredients for two weeks, monitoring your child's behaviour for improvement and then gradually re-introducing the foods one week at a time to see which negatively impacts his behaviour.  You may find that working with a nutritionist or naturopath can help with this process.  Some parents find that diet makes a huge difference in their child's behaviour and it is worth the difficulty of eliminating foods.  Other parents do not find that it makes much difference.  Each child is unique so experimentation is required.  I wish you the best of luck!