My son is one of those extreme cases where diet has a huge effect on his ADHD-like symptoms. I have a scientific background (PhD in physics) and I have spent years investigating this. My husband and I would do all kinds of experiments on DS when he was 5 or 6. We would sit him down at the table and have have him write a few sentences. While he was writing, we would give him a trial food to munch on. Within a short period of time (10 minutes or so), his handwriting would change dramatically. Letters would suddenly be printed backwards. The spacing between letters would go haywire. And then he would start babbling at ninety miles an hour. You could just see his brain start to spin wildly. He is now older (12) and can feel and articulate when he has eaten something or been exposed to a chemical (like perfume) that makes him feel extremely jittery and impulsive.

However, I would caution that some of what the NFT says sounds a little short on scientific basis. We have tried many things with our son: Feingold diet, low salicylates, etc. Ultimately we took him to a food allergy specialist about four years ago. He was diagnosed as being allergic to corn, wheat (gluten), eggs, dairy, and soy via skin prick testing and elimination diet. He also seems to be very sensitive to salicylates. It doesn't leave him with a whole lot of variety of foods, but the difference between him on the diet and not is huge! As a side note, he is extremely healthy during the school year, and never misses a day due to colds or the flu. It seems like if his diet was completely out of whack, we would see the results in his ability to fend off germs.

My current philosophy is that there are some kids who have "leaky guts" due to either food allergies/intolerances or an imbalance of good/bad bacteria which leads to an inflamed digestive system. When the digestive system is damaged, food is not broken down correctly and pieces of food (proteins) that are unprocessed get absorbed by the damaged digestive track. There is some research that these proteins can act like opiates on the brain. We are taking the approach of trying to heal his digestive system so that it functions better, with the hope that he will tolerate more foods.

Each kids is so very different. My child sounds a lot like MumofThree's eldest but may not resemble your child at all? It is just a question of whether you see any effects of food on his behavior or attention. You might try reading up on several things before your next meeting so that you can ask pointed questions to the NFT about the proposed diet.

Here is a quick link to a recent article on ABC news that might help:
ADHD From Allergy? Study Shows Benefit From Diet
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Though Daines is willing to work with families who want to try an elimination diet for treating ADHD, he feels it will only have an effect if the child is having a true food allergy or intolerance.

Edris felt similarly: Because ADHD can only be diagnosed by a cluster of symptoms (and not something biological such as a blood test), she thought that it was more likely that some children had allergy-related ADHD and it was only such children who would see a benefit from the diet.

Mom to DS12 and DD3