I have ADD and Cronic Depressive Disorder, and have moved to a low(er)-protein, low sugar diet (I still eat donughts or a slice of pie twice a week or so, but that's about it). It has helped me significantly in both the ADD and the Depressive area. I once (while on this low protein diet for moral reasons - before the idea of brain power had even been considered) had a deer burger, and found that my depression made a significant re-surgance for an 8 hour period after eating the burger (I was suicidal for no appearent reason). I didn't connect the mood swing to the food consumption until afterwards, at which time, I engaged a few friends to help me test the theory. Not a scientific study by any means, but it seems that a high surge in protein in an individual's diet can significanly increase depressive mood swings.
Also, there is currently a number of scientific studies underway showing that a high sugar diet as a child can increase ADD symptoms and chances of retaining ADD symptoms significantly (preliminary findings).
http://www.alternet.org/story.html?StoryID=15315
though there are also studies saying it makes litte difference.
http://www.drspock.com/article/0,1510,4126,00.html?r=related
I think that most of today's studies of ADHD treatments are all very skewed, however, given two things:
1)mis-diagnosis of ADHD in Children is rampent. How can the studies of a treatment be effective if there are no exact rules on how to diagnose a victim of it?
2)excitment factor. Even given long-term studies, I can say from personal expirience, that as soon as a kidd with ADD knows he is being studied for the sake of science, his hyperactivity/excitment level will go up about 15%. So if the diet makes a 15% difference in their behavior, then, overall, you will see no net effect.
As for your children specifically, care for them, but don't worry so much. I have found that most people with ADHD are extremely intelligent; part of the reason that they have a hard time focusing is that they have thoughts goings through their heads at 50x the speed of a normal person. How can you focus on addition for 45 minutes straight when your brain wants to consider the implications of how wind currents effect the flight paths of migrating birds? I used to get bad grades in kindergarden, because I was anti-social, and would "stand by the water fountain for hours at a time". If anyone had ever bothered to ask, I would have explained to them that I was tracking the pathways of the water rivulets as they traveled out of the spigot and down the drain. And they thought I was slow
The best description I have ever heard is this:
"A normal person has one TV which shows them the world. they can change the channel, and look at different things, but they only have one show on at a time. A person with ADHD has 50 TV's. Most of the time, they are each tuned to a different channel, and it is very hard to keep focused on one thing when this is going on. But every once in a while, every TV gets tuned to the same chennel, and you end up with an ADD kid "super-focused", to the point where the outside world doesn't exsist"
I know this description applies to most fo the ADD/ADHD people I know.
Good luck!
[edit:::
1) Proccesed foods, obviously these cannot be avoided completely but where there is a substitute try that instead, procceses like milling often removes over 80 percent of vitamin content from a food.
not only that, but it has been shown that eating proccessed starched leads to uneven spikes of sugar in the bloodstream, which has been linked to the possible development of typeII diabetes later in life.
who would of thunk it, the more we study diet and health, the more we realize that a diet similar to the one we evolved eating is the healthiest for us. surprise surprise. I also find that given humans have evolved an upright posture, walking is a good mode of transportation for me
(sorry for the sarcasm, but it seems so plainly obvious, once you consider it for a while!)
[edit2::
by chance there is a thread on this exact thing:
http://www.sciforums.com/showthread.php?s=&threadid=26699